Oxidative desulfurization of fuels catalyzed by Fenton-like ionic liquids at room temperature.

PubMed

Jiang, Yunqing; Zhu, Wenshuai; Li, Huaming; Yin, Sheng; Liu, Hua; Xie, Qingjie

2011-03-21

Oxidation of the sulfur-containing compounds benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been studied in a desulfurization system composed of model oil, hydrogen peroxide, and different types of ionic liquids [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3), [(C(8)H(17))(3)CH(3)N]Cl/CuCl(2), [(C(8)H(17))(3)CH(3)N]Cl/ZnCl(2), [(C(8)H(17))(3)CH(3)N]Cl/SnCl(2), [(C(4)H(9))(3)CH(3)N]Cl/FeCl(3), [C(10)H(21)(CH(3))(3)N]Cl/FeCl(3), [(C(10)H(21))(2)(CH(3))(2)N]Cl/FeCl(3). Deep desulfurization is achieved in the Fenton-like ionic liquid [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) at 25 °C for 1 h. The desulfurization of DBT reaches 97.9%, in consuming very low amount of [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) (only 0.702 mmol). The reaction conditions, for example, the amount of [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) or H(2)O(2), the temperature, and the molar ratio of FeCl(3) to [(C(8)H(17))(3)CH(3)N]Cl, are investigated for this system. The oxidation reactivity of the different sulfur-containing compounds is found to decrease in the order of DBT>BT>4,6-DMDBT. The desulfurization system can be recycled six times without significant decrease in activity. The sulfur level of FCC gasoline could be reduced from 360 ppm to 110 ppm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Palladium complexes of a phosphorus ylide with two stabilizing groups: synthesis, structure, and DFT study of the bonding modes.

PubMed

Falvello, Larry R; Ginés, Juan Carlos; Carbó, Jorge J; Lledós, Agustí; Navarro, Rafael; Soler, Tatiana; Urriolabeitia, Esteban P

2006-08-21

The phosphorus ylide ligand [Ph3P=C(CO2Me)C(=NPh)CO2Me] (L1) has been prepared and fully characterized by spectroscopic, crystallographic, and density functional theory (DFT) methods (B3LYP level). The reactivity of L1 toward several cationic Pd(II) and Pt(II) precursors, with two vacant coordination sites, has been studied. The reaction of [M(C/\\X)(THF)2]ClO4 with L1 (1:1 molar ratio) gives [M(C/\\X)(L1)]ClO4 [M = Pd, C/\\X = C6H4CH2NMe2 (1), S-C6H4C(H)MeNMe2 (2), CH2-8-C9H6N (3), C6H4-2-NC5H4 (4), o-CH2C6H4P(o-tol)2 (6), eta3-C3H5 (7); M = Pt, C/\\X = o-CH2C6H4P(o-tol)2 (5); M(C/\\X) = Pd(C6F5)(SC4H8) (8), PdCl2 (9)]. In complexes 1-9, the ligand L1 bonds systematically to the metal center through the iminic N and the carbonyl O of the stabilizing CO2Me group, as is evident from the NMR data and from the X-ray structure of 3. Ligand L1 can also be orthopalladated by reaction with Pd(OAc)2 and LiCl, giving the dinuclear derivative [Pd(mu-Cl)(C6H4-2-PPh2=C(CO2Me)C(CO2Me)=NPh)]2 (10). The X-ray crystal structure of 10 is also reported. In none of the prepared complexes 1-10 was the C(alpha) atom found to be bonded to the metal center. DFT calculations and Bader analysis were performed on ylide L1 and complex 9 and its congeners in order to assess the preference of the six-membered N,O metallacycle over the four-membered C,N and five-membered C,O rings. The presence of two stabilizing groups at the ylidic C causes a reduction of its bonding capabilities. The increasing strength of the Pd-C, Pd-O, and Pd-N bonds along with other subtle effects are responsible for the relative stabilities of the different bonding modes.

Reactions between atomic chlorine and pyridine in solid para-hydrogen: infrared spectrum of the 1-chloropyridinyl (C5H5N-Cl) radical.

PubMed

Das, Prasanta; Bahou, Mohammed; Lee, Yuan-Pern

2013-02-07

With infrared absorption spectra we investigated the reaction between Cl atom and pyridine (C(5)H(5)N) in a para-hydrogen (p-H(2)) matrix. Pyridine and Cl(2) were co-deposited with p-H(2) at 3.2 K; a planar C(5)H(5)N-Cl(2) complex was identified from the observed infrared spectrum of the Cl(2)/C(5)H(5)N/p-H(2) matrix. Upon irradiation at 365 nm to generate Cl atom in situ and annealing at 5.1 K for 3 min to induce secondary reaction, the 1-chloropyridinyl radical (C(5)H(5)N-Cl) was identified as the major product of the reaction Cl + C(5)H(5)N in solid p-H(2); absorption lines at 3075.9, 1449.7, 1200.6, 1148.8, 1069.3, 1017.4, 742.9, and 688.7 cm(-1) were observed. The assignments are based on comparison of observed vibrational wavenumbers and relative IR intensities with those predicted using the B3PW91/6-311++G(2d, 2p) method. The observation of the preferential addition of Cl to the N-site of pyridine to form C(5)H(5)N-Cl radical but not 2-, 3-, or 4-chloropyridine (ClC(5)H(5)N) radicals is consistent with the reported theoretical prediction that formation of the former proceeds via a barrierless path.

Simple preparations of Pd6Cl12, Pt6Cl12, and Qn[Pt2Cl8+n], n=1, 2 (Q=TBA+, PPN+) and structural characterization of [TBA][Pt2Cl9] and [PPN]2[Pt2Cl10].C7H8.

PubMed

Dell'Amico, Daniela Belli; Calderazzo, Fausto; Marchetti, Fabio; Ramello, Stefano; Samaritani, Simona

2008-02-04

The hexanuclear Pd6Cl12, i.e., the crystal phase classified as beta-PdCl2, was obtained by reacting [TBA]2[Pd2Cl6] with AlCl3 (or FeCl3) in CH2Cl2. The action of AlCl3 on PtCl42-, followed by digestion of the resulting solid in 1,2-C2H4Cl2 (DCE), CHCl3, or benzene, produced Pt6Cl12.DCE, Pt6Cl12.CHCl3, or Pt6Cl12.C6H6, respectively. Treating [TBA]2[PtCl6] with a slight excess of AlCl3 afforded [TBA][Pt2Cl9], whose anion was established crystallographically to be constituted by two "PtCl6" octahedra sharing a face. Dehydration of H2PtCl6.nH2O with SOCl2 gave an amorphous compound closely analyzing as PtCl4, reactive with [Q]Cl in SOCl2 to yield [Q][Pt2Cl9] or [Q]2[Pt2Cl10], depending on the [Q]Cl/Pt molar ratio (Q=TBA+, PPN+). A single-crystal X-ray diffraction study has shown [PPN]2[Pt2Cl10].C7H8 to contain dinuclear anions formed by two edge-sharing PtCl6 octahedra.

Synthesis and characterization of water-soluble, heteronuclear ruthenium(III)/ferrocene complexes and their interactions with biomolecules.

PubMed

Anderson, Craig M; Jain, Swapan S; Silber, Lisa; Chen, Kody; Guha, Sumedha; Zhang, Wancong; McLaughlin, Emily C; Hu, Yongfeng; Tanski, Joseph M

2015-04-01

The reaction of Na[RuCl4(SO(CH3)2)2], 1, with one equivalent of FcCONHCH2C6H4N (Fc=FeC10H9), L1, FcCOOCH2CH2C3H3N2, L2, FcCOOC6H4N, L3, afforded the dinuclear species, Na[FcCONHCH2C6H4N[RuCl4(SO(CH3)2)

Group 4 metal mono-dicarbollide piano stool complexes. Synthesis, structure, and reactivity of ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})M(NR{sub 2}){sub 2}(NHR{sub 2}) (M = Zr, R = Et; M = Ti, R = Me, Et)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, D.E.; Jordan, R.F.; Rogers, R.D.

1995-08-01

The amine elimination reaction of C{sub 2}B{sub 9}H{sub 13} and Zr(NEt{sub 2}){sub 4} yields the mono-dicarbollide complex ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(NHEt{sub 2}), (1), which has been shown to adopt a three-legged piano stool structure by X-ray crystallography. Crystal data for 1: space group P2{sub 1}/c, a = 10.704(4) A, b = 11.066(3) A, c = 20.382(8) A, {beta} = 99.20(3){degree}, V = 2383(1) A{sup 3}, Z = 4. Complex 1 undergoes facile ligand substitution by THF and 4-picoline, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}-(THF) (2) and ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline){sub 2} (3).more » Compound 3 exists as the four-coordinate species ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline) in CH{sub 2}Cl{sub 2} solution. Complex 1 reacts selectively with 2 equiv of [NH{sub 2}ET{sub 2}]Cl, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})ZrCl{sub 2}(NHEt{sub 2}){sub 2} (4). Similarly, the reaction of C{sub 2}B{sub 9}H{sub 13} and Ti(NR{sub 2}){sub 4} yields ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Ti(NR{sub 2}){sub 2}(NHR{sub 2}) (5, R = Me; 6, R = Et). Compounds 1-6 are potential precursors to group 4 metal ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})MR{sub 2}L{sub n} alkyl species. 25 refs., 3 figs., 3 tabs.« less

ANALYSES OF THE INTERACTIONS WITHIN BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3H10T1/2CL8 CELLS

EPA Science Inventory

ANALYSES OF THE INTERACTIONS WITHIN BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3HIOT1/2 CL8 CELLS.

Studies of defined mixtures of carcinogenic polycyclic aromatic hydrocarbons (PAH) have identified three major categories of interacti...

The selective activation of a C-F bond with an auxiliary strong Lewis acid: a method to change the activation preference of C-F and C-H bonds.

PubMed

Wang, Lin; Sun, Hongjian; Li, Xiaoyan; Fuhr, Olaf; Fenske, Dieter

2016-11-15

The selective activation of the C-F bonds in substituted (2,6-difluorophenyl)phenylimines (2,6-F 2 H 3 C 6 -(C[double bond, length as m-dash]NH)-n'-R-C 6 H 4 (n' = 2, R = H (1); n' = 2, R = Me (2); n' = 4, R = tBu (3))) by Fe(PMe 3 ) 4 with an auxiliary strong Lewis acid (LiBr, LiI, or ZnCl 2 ) was explored. As a result, iron(ii) halides ((H 5 C 6 -(C[double bond, length as m-dash]NH)-2-FH 3 C 6 )FeX(PMe 3 ) 3 (X = Br (8); Cl (9)) and (n-RH 4 C 6 -(C[double bond, length as m-dash]NH)-2'-FH 3 C 6 )FeX(PMe 3 ) 3 (n = 2, R = Me, X = Br (11); n = 4, R = tBu, X = I (12))) were obtained. Under similar reaction conditions, using LiBF 4 instead of LiBr or ZnCl 2 , the reaction of (2,6-difluorophenyl)phenylimine with Fe(PMe 3 ) 4 afforded an ionic complex [(2,6-F 2 H 3 C 6 -(C[double bond, length as m-dash]NH)-H 4 C 6 )Fe(PMe 3 ) 4 ](BF 4 ) (10) via the activation of a C-H bond. The method of C-F bond activation with an auxiliary strong Lewis acid is appropriate for monofluoroarylmethanimines. Without the Lewis acid, iron(ii) hydrides ((2-RH 4 C 6 -(C[double bond, length as m-dash]NH)-2'-FH 3 C 6 )FeH(PMe 3 ) 3 (R = H (13); Me (14))) were generated from the reactions of Fe(PMe 3 ) 4 with the monofluoroarylmethanimines (2-FH 4 C 6 -(C[double bond, length as m-dash]NH)-2'-RC 6 H 4 (R = H (4); Me (5))); however, in the presence of ZnCl 2 or LiBr, iron(ii) halides ((2-RH 4 C 6 -(C[double bond, length as m-dash]NH)-H 4 C 6 )FeX(PMe 3 ) 3 (R = H, X = Cl (15); R = Me, X = Br (16))) could be obtained through the activation of a C-F bond. Furthermore, a C-F bond activation with good regioselectivity in (pentafluorophenyl)arylmethanimines (F 5 C 6 -(C[double bond, length as m-dash]NH)-2,6-Y 2 C 6 H 3 (Y = F (6); H (7))) could be realized in the presence of ZnCl 2 to produce iron(ii) chlorides ((2,6-Y 2 H 3 C 6 -(C[double bond, length as m-dash]NH)-F 4 C 6 )FeCl(PMe 3 ) 3 (Y = F (17); H (18))). This series of iron(ii) halides could be used to catalyze the hydrosilylation reaction of aldehydes. Due to the stability of iron(ii) halides to high temperature, the reaction mixture was allowed to be heated to 100 °C and the reaction could finish within 0.5 h.

Electrical conductivity of KAlCl4-ZrCl4 molten mixtures

NASA Astrophysics Data System (ADS)

Salyulev, A. B.; Khokhlov, V. A.; Moskalenko, N. I.

2017-02-01

The electrical conductivity of commercially challenging KAlCl4-ZrCl4 molten mixtures has been studied as a function of temperature (in the range from 345°C to 500°C) and the ZrCl4 concentration (0‒32.5mol %) using cells of a unique design. It is found to vary in the range from 0.41 to 0.80 S cm-1, increasing with temperature or when the mole concentration of zirconium tetrachloride in molten mixtures decreases.

Crystal structure, quantum mechanical investigation, IR and NMR spectroscopy of two new organic perchlorates: (C6H18N3)·(ClO4)3H2O (I) and (C9H11N2)·ClO4(II)

NASA Astrophysics Data System (ADS)

Bayar, I.; Khedhiri, L.; Soudani, S.; Lefebvre, F.; Ferretti, V.; Ben Nasr, C.

2018-06-01

The reaction of perchloric acid with 1-(2-aminoethyl)piperazine or 5,6-dimethyl-benzimidazole results in the formation of 1-(2-amonioethyl)piperazine-1,4-dium triperchlorate hydrate (C6H18N3)·(ClO4)3·H2O (I) or 5,6-dimethyl-benzylimidazolium perchlorate (C9H11N2)·ClO4(II). Both compounds were fully structurally characterized including single crystal X-ray diffraction analysis. Compound (I) crystallizes in the centrosymmetric triclinic space group P 1 bar with the lattice parameters a = 7.455 (2), b = 10.462 (2), c = 10.824 (2) Å, α = 80.832 (2), β = 88.243 (2), γ = 88.160 (2) °, Z = 2 and V = 832.77 (3) Å3. Compound (II) has been found to belong to the P21/c space group of the monoclinic system, with a = 7.590 (3), b = 9.266 (3), c = 16.503 (6) Å, β = 107.38 (2) °, V = 1107.69 (7) Å3 and Z = 4. The structures of (I) and (II) consist of slightly distorted [ClO4]- tetrahedra anions and 1-(2-amonioethyl)piperazine-1,4-dium trication (I) or 5,6-dimethyl-benzylimidazolium cations (II) and additionally a lattice water in (I). The crystal structures of (I) and (II) exhibit complex three-dimensional networks of H-bonds connecting all their components. In the atomic arrangement of (I), the ClO4- anions form corrugated chains, while in (II) the atomic arrangement exhibits wide pseudo-hexagonal channels of ClO4 tetrahedra including the organic entities. The lattice water serves as a link between pairs of cations and pairs of anions via several Osbnd H⋯O and N-H⋯O interactions in compound (I). The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid-state 13C, 35Cl and 15N NMR spectroscopy. DFT calculations allowed the attribution of the IR and NMR bands. Intermolecular interactions were investigated by Hirshfeld surfaces. Electronic properties such as HOMO and LUMO energies were derived.

The ultrasound-assisted oxidative scission of monoenic fatty acids by ruthenium tetroxide catalysis: influence of the mixture of solvents.

PubMed

Rup, Sandrine; Zimmermann, François; Meux, Eric; Schneider, Michel; Sindt, Michele; Oget, Nicolas

2009-02-01

Carboxylic acids and diacids were synthesized from monoenic fatty acids by using RuO4 catalysis, under ultrasonic irradiation, in various mixtures of solvents. Ultrasound associated with Aliquat 336 have promoted in water, the quantitative oxidative cleavage of the CH=CH bond of oleic acid. A design of experiment (DOE) shows that the optimal mixture of solvents (H2O/MeCN, ratio 1/1, 2.2% RuCl3/4.1 eq. NaIO4) gives 81% azelaic acid and 97% pelargonic acid. With the binary heterogeneous mixture H2O/AcOEt, the oxidation of the oleic acid leads to a third product, the alpha-dione 9,10-dioxostearic acid.

Hydrogen-alkali exchange between silicate melts and two-phase aqueous mixtures: an experimental investigation

NASA Astrophysics Data System (ADS)

Williams, Thomas J.; Candela, Philip A.; Piccoli, Philip M.

Experiments were performed in the three-phase system high-silica rhyolite melt + low-salinity aqueous vapor + hydrosaline brine, to investigate the exchange equilibria for hydrogen, potassium, and sodium in magmatic-hydrothermal systems at 800 °C and 100 MPa, and 850 °C and 50 MPa. The Kaqm/meltH,Na and Kaqm/meltH,K for hydrogen-sodium exchange between a vapor + brine mixture and a silicate melt are inversely proportional to the total chloride concentration (ΣCl) in the vapor + brine mixture indicating that HCl/NaCl and HCl/KCl are higher in the low-salinity aqueous vapor relative to high-salinity brine. The equilibrium constants for vapor/melt and brine/melt exchange were extracted from regressions of Kaqm/meltH,Na and Kaqm/meltH,K versus the proportion of aqueous vapor relative to brine in the aqueous mixture (Faqv) at P and T, expressed as a function of ΣCl. No significant pressure effect on the empirically determined exchange constants was observed for the range of pressures investigated. Model equilibrium constants are: Kaqv/meltH,Na(vapor/melt)=26(+/-1.3) at 100 MPa (800 °C), and 19( +/- 7.0) at 50 MPa (850 °C) Kaqv/meltH,K=14(+/-1.1) at 100 MPa (800 °C), and 24(+/-12) at 50 MPa (850 °C) Kaqb/meltH,b(brine/melt)= 1.6(+/-0.7) at 100 MPa (800 °C), and 3.9(+/-2.3) at 50 MPa (850 °C) and Kaqb/meltH,K=2.7(+/-1.2) at 100 MPa (800 °C) and 3.8(+/-2.3) at 50 MPa (850 °C). Values for Kaqv/meltH,K and Kaqb/meltH,K were used to calculate KCl/HCl in the aqueous vapor and brine as a function of melt aluminum saturation index (ASI: molar Al2O3/(K2O+Na2O+CaO) and pressure. The model log KCl/HCl values show that a change in melt ASI from peraluminous (ASI = 1.04) to moderately metaluminous (ASI = 1.01) shifts the cooling pathway (in temperature-log KCl/HCl space) of the aqueous vapor toward the andalusite+muscovite+K-feldspar reaction point.

Coordination-organometallic hybrid materials based on the trinuclear M(II)-Ru(II) (M=Ni and Zn) complexes: Synthesis, structural characterization, luminescence and electrochemical properties

NASA Astrophysics Data System (ADS)

Pawal, S. B.; Lolage, S. R.; Chavan, S. S.

2018-02-01

A new series of trinuclear complexes of the type Ni[R-C6H4Ndbnd CH(O)C6H3Ctbnd CRu(dppe)2Cl]2 (1a-c) and Zn[Rsbnd C6H4Ndbnd CH(O)C6H3Ctbnd CRu(dppe)2Cl]2 (2a-c) have been prepared from the reaction of trans-[RuCl(dppe)2Ctbnd Csbnd C6H3(OH)(CHO)] (1) with aniline, 4-nitroaniline and 4-methoxyaniline (R1-3) in presence of nickel acetate and zinc acetate in CH2Cl2/MeOH (1:1) mixture. The structural properties of the complexes have been characterized by elemental analyses and spectroscopic techniques viz. FTIR, UV-Visible, 1H NMR and 31P NMR spectral studies. The crystal structure and morphology of the hybrid complexes was investigated with the help of X-ray powder diffraction (XRPD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The thermal properties of 1a-c and 2a-c were studied by thermogravimetric (TG) analysis. The electrochemical behaviour of the complexes reveals that all complexes displayed a quasireversible redox behaviour corresponding to Ru(II)/Ru(III) and Ni(II)/Ni(III) couples for 1a-c and only Ru(II)/Ru(III) couple for 2a-c. All complexes are emissive in solution at room temperature revealing the influence of substituents and solvent polarity on emission properties of the complexes.

Synthesis and Characterization of Atomically Precise Copper Nanoclusters

NASA Astrophysics Data System (ADS)

Nguyen, Thuy-Ai Dang

The reactivity of MCl3(eta1-TEMPO) (M = Fe, Al; TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) with a variety of lignin models, including 3,4-dimethoxybenzyl alcohol, 1-phenyl-2-phenoxyethanol and 1,2-diphenyl-2-methoxyethanol is investigated. FeCl3(TEMPO) is effective in cleanly converting these substrates to the corresponding aldehyde or ketone. AlCl3(eta1-TEMPO) is also able to oxidize these substrates, however in a few instances the products of over-oxidation are also observed. In contrast, 2-phenoxyethanol is not oxidized by MCl 3(eta1-TEMPO); instead it likely coordinates to the metal center, forming a 2-phenoxyethoxide complex. Oxidation of activated alkanes by MCl3(eta1-TEMPO) suggests that the reactions proceed via an initial 1-electron concerted proton-electron transfer (CPET) event. Finally, reaction of TEMPO with FeBr3 in Et 2O results in oxidation of the solvent. The copper hydride clusters [Cu14H12(phen) 6(PPh3)4][X]2 (X = Cl, OTf) are obtained in good yields by reaction of [(Ph3P)CuH]6 with 1,10-phenanthroline, in the presence of a halide or pseudohalide source. [Cu14H 12(phen)6(PPh3)4][Cl]2 reacts with CO2 in CH2Cl2, in the presence of excess Ph3P, to form the formate complex, [(Ph3P)2Cu(kappa 2-O2CH)], along with [(phen)(Ph3P)CuCl]. [Cu25H22(PPh3)12]Cl and [Cu 18H17(PPh3)10]Cl, are isolated from the reaction of Cu(OAc) and CuCl with Ph2SiH2, in the presence of PPh3. [Cu25H22(PPh3) 12]Cl formally features partial Cu(0) character. Subsequent reaction with Ph2phen resulted in the isolation of [Cu29Cl 4H22(Ph2phen)12]Cl (Ph2phen = 4,7-diphenyl-1,10-phenanthroline), in good yields. A time-resolved kinetic evaluation of the formation of [Cu29Cl4H22(Ph 2phen)12]Cl reveals that the mechanism of cluster growth is initiated by rapid ligand exchange, followed by slower extrusion of CuCl monomer, transport, and subsequent capture by intact clusters. Two Cu26 nanoclusters, tentatively formulated as [Cu 26H17(PPh3)9(OAc)3] and [Cu26H22(PPh3)10(OAc)2], are isolated from the reaction of Cu(OAc) with Ph2SiH2, in the presence of PPh3. As formulated, [Cu26H 17(PPh3)9(OAc)3] features a magic number N* = 6, which is unprecedented for a copper nanocluster. XANES supports an assignment of more Cu(0) character than [Cu25H 22(PPh3)12]Cl (N* = 2) for this complex. A critical reevaluation of the synthesis and characterization of Cu 8(MPP)4 is reported. This product was reportedly formed by reaction of Cu(NO3)2 with 2-mercapto-5-n-propylpyrimidine (HMPP) and NaBH4, in ethanol, in the presence of [N(C8H 17)4][Br]. However, upon reevaluation, no experimental evidence to support the existence of Cu8(MPP)4 was found. Instead, the material isolated from this reaction is a complex mixture containing [N(C8H17)4]+, Br -, NO3-, 2-mercapto-5-n-propyl-1,6-dihydropyrimidine (H2MPP*), along with the Cu(I) coordination polymer, [Cu(MPP)]n. H2MPP* and [Cu(MPP)]n, as well as the related Cu(I) coordination complexes, [Cu(HMPP*)]n and [Cu2(MPP*)]n are independently synthesized to support these conclusions.

Halides Held by Bifurcated Chalcogen-Hydrogen Bonds. Effect of μ(S,N-H)Cl Contacts on Dimerization of Cl(carbene)PdII Species.

PubMed

Mikherdov, Alexander S; Novikov, Alexander S; Kinzhalov, Mikhail A; Boyarskiy, Vadim P; Starova, Galina L; Ivanov, Alexander Yu; Kukushkin, Vadim Yu

2018-03-19

The reaction of cis-[PdCl 2 (CNCy) 2 ] (1) with thiazol-2-amines (2-10) leads to the C,N-chelated diaminocarbene-like complexes [PdCl{ C(N(H)4,5-R 2 -thiazol-2-yl)NHCy}(CNCy)] (11-14; 82-91%) in the case of 4,5-R 2 -thiazol-2-amines (R, R = H, H (2), Me, Me (3), -(CH 2 ) 4 - (4)) and benzothiazol-2-amine (5) or gives the diaminocarbene species cis-[PdCl 2 {C(N(H)Cy)N(H)4-R-thiazol-2-yl}(CNCy)] (15-19; 73-93%) for the reaction with 4-aryl-substituted thiazol-2-amines (R = Ph (6), 4-MeC 6 H 4 (7), 4-FC 6 H 4 (8), 4-ClC 6 H 4 (9), 3,4-F 2 C 6 H 3 (10)). Inspection of the single-crystal X-ray diffraction data for 15-17 and 19 suggests that the structures of all these species exhibit previously unrecognized bifurcated chalcogen-hydrogen bonding μ (S,N-H) Cl and also Pd II ···Pd II metallophilic interactions. These noncovalent interactions collectively connect two symmetrically located molecules of 15-17 and 19, resulting in their solid-state dimerization. The existence of the μ (S,N-H) Cl system and its strength (6-9 kcal/mol) were additionally verified/estimated by a Hirshfeld surface analysis and DFT calculations combined with a topological analysis of the electron density distribution within the formalism of Bader's theory (AIM method) and NBO analysis. The observed noncovalent interactions are jointly responsible for the dimerization of 15-19 not only in the solid phase but also in CHCl 3 solutions, as predicted theoretically by DFT calculations and confirmed experimentally by FTIR, HRESI-MS, 1 H NMR, and diffusion coefficient NMR measurements. Available CCDC data were processed under the new moiety angle, and the observed μ (S,E-H) Cl systems were classified accordingly to E (E = N, O, C) type atoms.

Synchronized flash photolysis and pulse deposition in matrix isolation experiments

NASA Technical Reports Server (NTRS)

Allamandola, Louis J.; Lucas, Donald; Pimentel, George C.

1978-01-01

An apparatus is described which permits flash photolysis of a pulse-deposited gas mixture in a matrix isolation experiment. This technique obviates the limitations of in situ photolysis imposed by the cage effect and by secondary photolysis. The matrix is deposited in pulses at 30-s intervals and photolyzed sequentially by four synchronized flashlamps approximately 1 ms before the pulse strikes the cold surface. Pulsed deposition maintains adequate isolation and causes line narrowing, which enhances spectral sensitivity. The efficacy of flash photolysis combined with pulsed deposition for producing and trapping transient species was demonstrated by infrated detection of CF3 (from photolysis of CF3I/Ar mixtures) and of ClCO (from photolysis of Cl2/CO/Ar mixtures). The apparatus was used to study the photolytic decomposition of gaseous tricarbonylironcyclobutadiene, C4H4Fe(CO)3. The results indicate that the primary photolytic step is not elimination of C4H4, as suggested earlier, but rather of CO.

(Phosphinoalkyl)silanes. 4.(1) Hydrozirconation as a Non-Photochemical Route to (Phosphinopropyl)silanes: Facile Assembly of the Bis(3-(diphenylphosphino)propyl)silyl ("biPSi") Ligand Framework. Access to the Related Poly(3-(dimethylsilyl)propyl)phosphines R(n)()P(CH(2)CH(2)CH(2)SiMe(2)H)(3)(-)(n)() (n = 1, R = Ph; n = 0).

PubMed

Zhou, Xiaobing; Stobart, Stephen R.; Gossage, Robert A.

1997-08-13

Treatment of SiEt(3)(CH=CH(2)) with ZrCp(2)HCl (Schwartz's reagent) followed by reaction with PPh(2)Cl provides a high-yield (75%) route to Ph(2)PCH(2)CH(2)SiEt(3), and accordingly hydrozirconation of CH(2)=CHCH(2)SiHMe(2) affords the intermediate ZrCp(2)(CH(2)CH(2)CH(2)SiHMe(2))Cl (2). The latter, which is very sensitive to hydrolysis and reacts with HCl forming SiHMe(2)Pr(n)() and with NBS or I(2) affording SiHMe(2)CH(2)CH(2)CH(2)X (X = Br (3), I (4)), behaves similarly with PPh(2)Cl, PPhCl(2), or PBr(3) undergoing cleavage to the known Ph(2)PCH(2)CH(2)CH(2)SiMe(2)H (i.e. chelH, A) and the novel bis- and tris(silylpropyl)phosphines PhP(CH(2)CH(2)CH(2)SiMe(2)H)(2) (5) and P(CH(2)CH(2)CH(2)SiMe(2)H)(3) (6), respectively, with concomitant formation of ZrCp(2)Cl(2). Corresponding hydroboration of allylsilanes is facile, but subsequent phosphine halide cleavage yields (phosphinoalkyl)silanes only as constituents of intractable mixtures. Hydrozirconation followed by phosphination with PPh(2)Cl also converts SiHMe(CH(2)CH=CH(2))(2) to SiHMe(CH(2)CH(2)CH(2)PPh(2))(2) (i.e. biPSiH, B) together with a propyl analogue Ph(2)PCH(2)CH(2)CH(2)SiMe(Pr(n)())H (7) of A (ca. 2:1 ratio), as well as SiH(CH(2)CH=CH(2))(3) to a mixture (ca. 5:2:1 ratio) of SiH(CH(2)CH(2)CH(2)PPh(2))(3) (i.e. triPSiH, C), a new analogue SiH(Pr(n)())(CH(2)CH(2)CH(2)PPh(2))(2) (8) of B, and a further analogue Ph(2)PCH(2)CH(2)CH(2)SiHPr(n)()(2) (9) of A. A further analogue SiH(2)(CH(2)CH(2)CH(2)PPh(2))(2) (10) of biPSiH (B) is obtained similarly starting from SiH(2)(CH(2)CH=CH(2))(2). Steric control of silylalkyl cleavage from 2 is indicated by the fact that, like PPh(2)Cl (which forms B), two further biPSiH analogues SiH(Me)[CH(2)CH(2)CH(2)P(n-hex)(2)](2) (11) and SiH(Me)(CH(2)CH(2)CH(2)PPhBz)(2) (12) were obtained using P(n-hex)(2)Cl (i.e. n-hex = CH(3)(CH(2))(4)CH(2)-) or PPhBzCl (i.e. Bz = -CH(2)C(6)H(5)), respectively, whereas neither PPr(i)(2)Cl nor PBu(t)(2)Cl led to (phosphinoalkyl)silane formation. The surface-substrate linking reagent Ph(2)PCH(2)CH(2)CH(2)Si(OEt)(3) (D) is formed efficiently by similar means from Si(OEt)(3)(CH(2)CH=CH(2)). NMR data ((1)H, (13)C, (29)Si, (31)P) for 2-12 have been measured and are discussed.

Studies of the kinetics and thermochemistry of the forward and reverse reaction Cl + C6H6 = HCl + C6H5.

PubMed

Alecu, I M; Gao, Yide; Hsieh, P-C; Sand, Jordan P; Ors, Ahmet; McLeod, A; Marshall, Paul

2007-05-17

The laser flash photolysis resonance fluorescence technique was used to monitor atomic Cl kinetics. Loss of Cl following photolysis of CCl4 and NaCl was used to determine k(Cl + C6H6) = 6.4 x 10(-12) exp(-18.1 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) over 578-922 K and k(Cl + C6D6) = 6.2 x 10(-12) exp(-22.8 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) over 635-922 K. Inclusion of literature data at room temperature leads to a recommendation of k(Cl + C6H6) = 6.1 x 10(-11) exp(-31.6 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) for 296-922 K. Monitoring growth of Cl during the reaction of phenyl with HCl led to k(C6H5 + HCl) = 1.14 x 10(-12) exp(+5.2 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) over 294-748 K, k(C6H5 + DCl) = 7.7 x 10(-13) exp(+4.9 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) over 292-546 K, an approximate k(C6H5 + C6H5I) = 2 x 10(-11) cm(3) molecule(-1) s(-1) over 300-750 K, and an upper limit k(Cl + C6H5I) < or = 5.3 x 10(-12) exp(+2.8 kJ mol(-1)/RT) cm(3) molecule(-1) s(-1) over 300-750 K. Confidence limits are discussed in the text. Third-law analysis of the equilibrium constant yields the bond dissociation enthalpy D(298)(C6H5-H) = 472.1 +/- 2.5 kJ mol(-1) and thus the enthalpy of formation Delta(f)H(298)(C6H5) = 337.0 +/- 2.5 kJ mol(-1).

Role of the NH2 functionality and solvent in terdentate CNN alkoxide ruthenium complexes for the fast transfer hydrogenation of ketones in 2-propanol.

PubMed

Baratta, Walter; Ballico, Maurizio; Esposito, Gennaro; Rigo, Pierluigi

2008-01-01

The reaction of [RuCl(CNN)(dppb)] (1; HCNN=6-(4-methylphenyl)-2-pyridylmethylamine) with NaOiPr in 2-propanol/C6D6 affords the alcohol adduct alkoxide [Ru(OiPr)(CNN)(dppb)].n iPrOH (5), containing the Ru-NH2 linkage. The alkoxide [Ru(OiPr)(CNN)(dppb)] (4) is formed by treatment of the hydride [Ru(H)(CNN)(dppb)] (2) with acetone in C6D6. Complex 5 in 2-propanol/C6D6 equilibrates quickly with hydride 2 and acetone with an exchange rate of (5.4+/-0.2) s(-1) at 25 degrees C, higher than that found between 4 and 2 ((2.9+/-0.4) s(-1)). This fast process, involving a beta-hydrogen elimination versus ketone insertion into the Ru-H bond, occurs within a hydrogen-bonding network favored by the Ru-NH2 motif. The cationic alcohol complex [Ru(CNN)(dppb)(iPrOH)](BAr(f)4) (6; Ar(f)=3,5-C6H3(CF3)2), obtained from 1, Na[BAr(f)4], and 2-propanol, reacts with NaOiPr to afford 5. Complex 5 reacts with either 4,4'-difluorobenzophenone through hydride 2 or with 4,4'-difluorobenzhydrol through protonation, affording the alkoxide [Ru(OCH(4-C6H4F)2)(CNN)(dppb)] (7) in 90 and 85 % yield of the isolated product. The chiral CNN-ruthenium compound [RuCl(CNN)((S,S)-Skewphos)] (8), obtained by the reaction of [RuCl2(PPh3)3] with (S,S)-Skewphos and orthometalation of HCNN in the presence of NEt3, is a highly active catalyst for the enantioselective transfer hydrogenation of methylaryl ketones (turnover frequencies (TOFs) of up to 1.4 x 10(6) h(-1) at reflux were obtained) with up to 89% ee. Also the ketone CF3CO(4-C6H4F), containing the strong electron-withdrawing CF3 group, is reduced to the R alcohol with 64% ee and a TOF of 1.5 x 10(4) h(-1). The chiral alkoxide [Ru(OiPr)(CNN)((S,S)-Skewphos)]n iPrOH (9), obtained from 8 and NaOiPr in the presence of 2-propanol, reacts with CF3CO(4-C6H4F) to afford a mixture of the diastereomer alkoxides [Ru(OCH(CF3)(4-C6H4F))(CNN)((S,S)-Skewphos)] (10/11; 74% yield) with 67% de. This value is very close to the enantiomeric excess of the alcohol (R)-CF3CH(OH)(4-C6H4F) formed in catalysis, thus suggesting that diastereoisomeric alkoxides with the Ru-NH2 linkage are key species in the catalytic asymmetric transfer hydrogenation reaction.

Determination of Natural and Depleted Uranium in Urine at the ppt Level: An Interlaboratory Analytical Exercise

DTIC Science & Technology

2002-10-01

but de cet exercice analytique 6tait d𔄀valuer toutes les techniques analytiques disponibles ayant la capacit6 de mesurer les rapports isotopiques...B Formulation. Step Component Amount added 1 2% v/v nitric acid 500 mL 2 Calcium chloride (CaCl2.2H 20) 12.6 g 3 2% v/v nitric acid Dilute to 1000 mL...chloride (KCI) 3.43 Sodium chloride (NaCl) 2.32 Creatinine (C4H7N30) 1.10 Ammonium chloride (NH 4Cl) 1.06 Hippuric acid (C9H9N03) 0.63 Calcium chloride

Highly productive CNN pincer ruthenium catalysts for the asymmetric reduction of alkyl aryl ketones.

PubMed

Baratta, Walter; Chelucci, Giorgio; Magnolia, Santo; Siega, Katia; Rigo, Pierluigi

2009-01-01

Chiral pincer ruthenium complexes of formula [RuCl(CNN)(Josiphos)] (2-7; Josiphos = 1-[1-(dicyclohexylphosphano)ethyl]-2-(diarylphosphano)ferrocene) have been prepared by treating [RuCl(2)(PPh(3))(3)] with (S,R)-Josiphos diphosphanes and 1-substituted-1-(6-arylpyridin-2-yl)methanamines (HCNN; substituent = H (1 a), Me (1 b), and tBu (1 c)) with NEt(3). By using 1 b and 1 c as a racemic mixture, complexes 4-7 were obtained through a diastereoselective synthesis promoted by acetic acid. These pincer complexes, which display correctly matched chiral PP and CNN ligands, are remarkably active catalysts for the asymmetric reduction of alkyl aryl ketones in basic alcohol media by both transfer hydrogenation (TH) and hydrogenation (HY), achieving enantioselectivities of up to 99 %. In 2-propanol, the enantioselective TH of ketones was accomplished by using a catalyst loading as low as 0.002 mol % and afforded a turnover frequency (TOF) of 10(5)-10(6) h(-1) (60 and 82 degrees C). In methanol/ethanol mixtures, the CNN pincer complexes catalyzed the asymmetric HY of ketones with H(2) (5 atm) at 0.01 mol % relative to the complex with a TOF of approximately 10(4) h(-1) at 40 degrees C.

Effects of molten-salt/ionic-liquid mixture on extraction of docosahexaenoic acid (DHA)-rich lipids from Aurantiochytrium sp. KRS101.

PubMed

Choi, Sun-A; Jung, Joo-Young; Kim, Kyochan; Kwon, Jong-Hee; Lee, Jin-Suk; Kim, Seung Wook; Park, Ji-Yeon; Yang, Ji-Won

2014-11-01

In this study, lipid extraction from Aurantiochytrium sp. was performed using a molten-salt/ionic-liquid mixture. The total fatty acid content of Aurantiochytrium sp. was 478.8 mg/g cell, from which 145 mg/g cell (30.3% of total fatty acids) of docosahexaenoic acid (DHA) was obtained. FeCl3·6H2O showed a high lipid extraction yield (207.9 mg/g cell), when compared with that of [Emim]OAc, which was only 118.1 mg/g cell; notably however, when FeCl3·6H2O was mixed with [Emim]OAc (5:1, w/w), the yield was increased to 478.6 mg/g cell. When lipid was extracted by the FeCl3·6H2O/[Emim]OAc mixture at a 5:1 (w/w) blending ratio under 90 °C, 30 min reaction conditions, the fatty acid content of the extracted lipid was a high purity 997.7 mg/g lipid, with most of the DHA having been extracted (30.2% of total fatty acids). Overall, lipid extraction from Aurantiochytrium sp. was enhanced by the synergistic effects of the molten-salt/ionic-liquid mixture with different ions.

Effect of thermal treatment and light irradiation on the stability of lycopene with high Z-isomers content.

PubMed

Murakami, Kazuya; Honda, Masaki; Takemura, Ryota; Fukaya, Tetsuya; Wahyudiono; Kanda, Hideki; Goto, Motonobu

2018-06-01

The stability of lycopene with high Z-isomers content during thermal treatment and light irradiation was investigated. Purified (all-E)-lycopene was thermally isomerized to the Z-isomers in dichloromethane (CH 2 Cl 2 ) at 50 °C for 24 h. The total content of the Z-isomers of lycopene reached 56.1%. Then, the mixture of lycopene isomers was stored in the dark at 4, 25, and 40 °C for 30 days, and under light irradiation using a fluorescent light at 4 °C for 336 h. The degradation rate of lycopene during thermal treatment rose with increasing temperature and the activation energy for decomposition of the mixture of lycopene isomers was calculated to be 71.0 kJ mol -1 . The degradation rate of lycopene isomers was almost the same under thermal treatment. On the other hand, during light irradiation, isomerization was promoted rather than decomposition, i.e. (9Z)- and (13Z)-lycopene converted to the (all-E)-isomer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Products from the Oxidation of n-Butane from 298 to 735 K Using Either Cl Atom or Thermal Initiation: Formation of Acetone and Acetic Acid-Possible Roaming Reactions?

PubMed

Kaiser, E W; Wallington, T J

2017-11-16

The oxidation of 2-butyl radicals (and to a lesser extent 1-butyl radicals) has been studied over the temperature range of 298-735 K. The reaction of Cl atoms (formed by 360 nm irradiation of Cl 2 ) with n-butane generated the 2-butyl radicals in mixtures of n-C 4 H 10 , O 2 , and Cl 2 at temperatures below 600 K. Above 600 K, 2-butyl radicals were produced by thermal combustion reactions in the absence of chlorine. The yields of the products were measured by gas chromatography using a flame ionization detector. Major products quantified include acetone, acetic acid, acetaldehyde, butanone, 2-butanol, butanal, 1- and 2- chlorobutane, 1-butene, trans-2-butene, and cis-2-butene. At 298 K, the major oxygenated products are those expected from bimolecular reactions of 2-butylperoxy radicals (butanone, 2-butanol, and acetaldehyde). As the temperature rises to 390 K, the butanone decreases while acetaldehyde increases because of the increased rate of 2-butoxy radical decomposition. Acetone and acetic acid first appear in significant yield near 400 K, and these species rise slowly at first and then sharply, peaking near 525 K at yields of ∼25 and ∼20 mol %, respectively. In the same temperature range (400-525 K), butanone, acetaldehyde, and 2-butanol decrease rapidly. This suggests that acetone and acetic acid may be formed by previously unknown reaction channels of the 2-butylperoxy radical, which are in competition with those that lead to butanone, acetaldehyde, and 2-butanol. Above 570 K, the yields of acetone and acetic acid fall rapidly as the yields of the butenes rise. Experiments varying the Cl atom density, which in turn controls the entire radical pool density, were performed in the temperature range of 410-440 K. Decreasing the Cl atom density increased the yields of acetone and acetic acid while the yields of butanone, acetaldehyde, and 2-butanol decreased. This is consistent with the formation of acetone and acetic acid by unimolecular decomposition channels of the 2-butylperoxy radical, which are in competition with the bimolecular channels that form butanone, acetaldehyde, and 2-butanol. Such unimolecular decomposition channels would be unlikely to proceed through conventional transition states because those states would be very constrained. Therefore, the possibility that these decomposition channels proceed via roaming should be considered. In addition, we investigated and were unable to fit our data trends by a simplified ketohydroperoxide mechanism.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buragohain, Amlan; Couck, Sarah; Van Der Voort, Pascal

Four existing and three new functionalized chromium terephthalates having MIL-101 topology and denoted as Cr-MIL-101-X (existing ones with X=–F, 1-F; –Cl, 2-Cl; –Br, 3-Br; –CH{sub 3}, 4-CH{sub 3}; new ones with X=–C{sub 6}H{sub 4}, 5-C{sub 6}H{sub 4}; –F{sub 2}, 6-F{sub 2}, –(CH{sub 3}){sub 2}, 7-(CH{sub 3}){sub 2}) were synthesized under hydrothermal conditions. All the materials except 5-C{sub 6}H{sub 4} could be prepared by a general synthetic route, in which the mixtures of CrO{sub 3}, H{sub 2}BDC-X (BDC=1,4-benzenedicarboxylate) linkers, conc. HCl and water with a molar ratio of 1:1:3.9:222.2 were reacted at 180 °C for 144 h. Compared to the 144more » h of synthesis time, three of the compounds, namely 1-Cl, 2-Br and 5-C{sub 6}H{sub 4}, could be prepared in much shorter reaction times (12–18 h at 180–210 °C). The materials possess high thermal stability up to 270–300 °C in an air atmosphere. The activated compounds exhibit significant porosity (S{sub BET} range: 1273–2135 m{sup 2} g{sup −1}). At 0 °C and 1 bar, the CO{sub 2} adsorption capacities of the compounds fall in the 1.7–2.9 mmol g{sup −1} range. Compounds 1-F and 6-F{sub 2} showed enhanced CO{sub 2} uptake values compared to parent Cr-MIL-101. The benzene adsorption capacities of the compounds lie in the range of 66.2–139.5 molecules per unit cell at 50 °C and p/p{sub 0}=0.35. The increased benzene uptake value of 1-F compared to un-functionalized Cr-MIL-101 and 4-CH{sub 3} suggests that the fluorination has induced more hydrophobicity in Cr-MIL-101 as compared to the methylation. - Graphical abstract: Benzene adsorption by seven functionalized Cr-MIL-101-X metal-organic framework (MOF) materials Display Omitted - Highlights: • Seven functionalized Cr-MIL-101-X materials were synthesized solvothermally. • All Cr-MIL-101-X materials exhibited high thermal stability up to 270–300 °C in air. • All Cr-MIL-101-X compounds displayed considerable porosity towards N{sub 2}, CO{sub 2} and benzene. • Mono- and di-fluorinated Cr-MIL-101 materials showed enhanced CO{sub 2} adsorption capacities. • Cr-MIL-101-F adsorbed more benzene than non- and methyl-functionalized Cr-MIL-101.« less

Synthesis and characterisation of ionic liquids based on 1-butyl-3-methylimidazolium chloride and MCl(4), M = Hf and Zr.

PubMed

Campbell, Paul S; Santini, Catherine C; Bouchu, Denis; Fenet, Bernard; Rycerz, Leszek; Chauvin, Yves; Gaune-Escard, Marcelle; Bessada, Catherine; Rollet, Anne-Laure

2010-02-07

Dialkylimidazolium chlorometallate molten salts resulting from the combination of zirconium or hafnium tetrachloride and 1-butyl-3-methylimidazolium chloride, [C(1)C(4)Im][Cl], have been prepared with a molar fraction of MCl(4), R = n(MCl4)/n(MCl4) + n([C1C4IM][Cl]) equal to 0, 0.1, 0.2, 0.33, 0.5, 0.67. The structure and composition were studied by Differential Scanning Calorimetry (DSC), (35)Cl (263 to 333 K), (1)H and (13)C solid state and solution NMR spectroscopy, and electrospray ionisation (ESI) mass spectrometry. The primary anions of the MCl(4)-based ILs were [MCl(5)], [MCl(6)] and [M(2)Cl(9)], whose relative abundances varied with R. For R = 0.33, pure solid [C(1)C(4)Im](2)[MCl(6)], for both M = Zr and Hf are formed (m.p. = 366 and 385 K, respectively). For R = 0.67 pure ionic liquids [C(1)C(4)Im][M(2)Cl(9)] for both M = Zr and Hf are formed (T(g) = 224 and 220 K, respectively). The thermal dissociation has been attempted of [C(1)C(4)Im](2)[HfCl(6)], and [C(1)C(4)Im](2)[ZrCl(6)] monitored by (35)Cl and (91)Zr solid NMR (high temperature up to 551 K).

Dynamic study of excited state hydrogen-bonded complexes of harmane in cyclohexane-toluene mixtures.

PubMed

Carmona, Carmen; Balón, Manuel; Galán, Manuel; Guardado, Pilar; Muñoz, María A

2002-09-01

Photoinduced proton transfer reactions of harmane or 1-methyl-9H-pyrido[3,4-b]indole (HN) in the presence of the proton donor hexafluoroisopropanol (HFIP) in cyclohexane-toluene mixtures (CY-TL; 10% vol/vol of TL) have been studied. Three excited state species have been identified: a 1:2 hydrogen-bonded proton transfer complex (PTC), between the pyridinic nitrogen of the substrate and the proton donor, a hydrogen-bonded cation-like exciplex (CL*) with a stoichiometry of at least 1:3 and a zwitterionic exciplex (Z*). Time-resolved fluorescence measurements evidence that upon excitation of ground state PTC, an excited state equilibrium is established between PTC* and the cationlike exciplex, CL*, lambdaem approximately/= 390 nm. This excited state reaction is assisted by another proton donor molecule. Further reaction of CL* with an additional HFIP molecule produces the zwitterionic species, Z*, lambda(em) approximately/= 500 nm. From the analysis of the multiexponential decays, measured at different emission wavelengths and as a function of HFIP concentration, the mechanism of these excited state reactions has been established. Thus, three rate constants and three reciprocal lifetimes have been determined. The simultaneous study of 1,9-dimethyl-9H-pyrido[3,4-b]indole (MHN) under the same experimental conditions has helped to understand the excited state kinetics of these processes.

Effects of Ti-Based Additives on the Hydrogen Storage Properties of a L i B H 4 / C a H 2 Destabilized System

DOE PAGES

Yang, Hongwei; Ibikunle, Adeola; Goudy, Andrew J.

2010-01-01

Tmore » he hydrogen storage properties of a destabilized LiBH 4 / CaH 2 system ball-milled with iCl 3 , iF 3 , and iO 2 additives have been investigated. It is found that the system with iCl 3 additive has a lower dehydrogenation temperature than the ones with other additives. Further study shows that a higher amount of iCl 3 is more effective in reducing the desorption temperature of the LiBH 4 / CaH 2 system, since it leads to a lower activation energy of dehydrogenation. he activations energies for mixtures containing 4, 10, and 25 mol% of iCl 3 are 141, 126, and 110 kJ/mol, respectively. However, the benefits of higher amounts of iCl 3 are offset by a larger reduction in hydrogen capacity of the mixtures.« less

Investigating the Weak to Evaluate the Strong: An Experimental Determination of the Electron Binding Energy of Carborane Anions and the Gas phase Acidity of Carborane Acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, Matthew M; Wang, Xue B; Reed, Christopher A

2009-12-23

Five CHB 11X 6Y 5 - carborane anions from the series X = Br, Cl, I and Y = H, Cl, CH 3 were generated by electrospray ionization, and their reactivity with a series of Brønsted acids and electron transfer reagents were examined in the gas phase. The undecachlorocarborane acid, H(CHB 11Cl 11), was found to be far more acidic than the former record holder, (1-C 4F 9SO 2) 2NH (i.e., ΔH° acid = 241 ± 29 vs 291.1 ± 2.2 kcal mol -1) and bridges the gas-phase acidity and basicity scales for the first time. Its conjugate base, CHBmore » 11Cl 11 -, was found by photoelectron spectroscopy to have a remarkably large electron binding energy (6.35 ± 0.02 eV) but the value for the (1-C 4F 9SO 2) 2N - anion is even larger (6.5 ± 0.1 eV). Consequently, it is the weak H-(CHB 11Cl 11) BDE (70.0 kcal mol -1, G3(MP2)) compared to the strong BDE of (1-C 4F 9SO 2) 2N-H (127.4 ± 3.2 kcal mol -1) that accounts for the greater acidity of carborane acids.« less

Abnormal carbene-silicon halide complexes.

PubMed

Wang, Yuzhong; Xie, Yaoming; Wei, Pingrong; Schaefer, Henry F; Robinson, Gregory H

2016-04-14

Reaction of the anionic N-heterocyclic dicarbene (NHDC), [:C{[N(2,6-Pr(i)2C6H3)]2CHCLi}]n (1), with SiCl4 gives the trichlorosilyl-substituted (at the C4 carbon) N-heterocyclic carbene complex (7). Abnormal carbene-SiCl4 complex (8) may be conveniently synthesized by combining 7 with HCl·NEt3. In addition, 7 may react with CH2Cl2 in warm hexane, giving the abnormal carbene-complexed SiCl3(+) cation (9). The nature of the bonding in 9 was probed with complementary DFT computations.

Roles of Bridging Ligand Topology and Conformation in Controlling Exchange Interactions between Paramagnetic Molybdenum Fragments in Dinuclear and Trinuclear Complexes.

PubMed

Ung VÂ, V&acaron;n Ân; Cargill Thompson, Alexander M. W.; Bardwell, David A.; Gatteschi, Dante; Jeffery, John C.; McCleverty, Jon A.; Totti, Federico; Ward, Michael D.

1997-07-30

The magnetic properties of two series of dinuclear complexes, and one trinuclear complex, have been examined as a function of the bridging pathway between the metal centers. The first series of dinuclear complexes is [{Mo(V)(O)(Tp)Cl}(2)(&mgr;-OO)], where "OO" is [1,4-O(C(6)H(4))(n)O](2)(-) (n = 1, 1; n = 2, 3), [4,4'-O(C(6)H(3)-2-Me)(2)O](2)(-) (4), or [1,3-OC(6)H(4)O](2)(-) (2) [Tp = tris(3,5-dimethylpyrazolyl)hydroborate]. The second series of dinuclear complexes is [{Mo(I)(NO)(Tp)Cl}(2)(&mgr;-NN)], where "NN" is 4,4'-bipyridyl (5), 3,3'-dimethyl-4,4'-bipyridine (6), 3,8-phenanthroline (7), or 2,7-diazapyrene (8). The trinuclear complex is [{Mo(V)(O)(Tp)Cl}(3)(1,3,5-C(6)H(3)O(3))] (9), whose crystal structure was determined [9.5CH(2)Cl(2): C(56)H(81)B(3)Cl(13)Mo(3)N(18)O(6); monoclinic, P2(1)/n; a = 13.443, b = 41.46(2), c = 14.314(6) Å; beta = 93.21(3) degrees; V = 7995(5) Å(3); Z = 4; R(1) = 0.106]. In these complexes, the sign and magnitude of the exchange coupling constant J is clearly related to both the topology and the conformation of the bridging ligand [where J is derived from H = -JS(1)().S(2)() for 1-8 and H = -J(S(1)().S(2)() + S(2)().S(3)() + S(1)().S(3)()) for 9]. The values are as follows: 1, -80 cm(-)(1); 2, +9.8 cm(-)(1); 3, -13.2 cm(-)(1); 4, -2.8 cm(-)(1); 5, -33 cm(-)(1); 6, -3.5 cm(-)(1); 7, -35.6 cm(-)(1); 8, -35.0 cm(-)(1); 9, +14.4 cm(-)(1). In particular the following holds: (1) J is negative (antiferromagnetic exchange) across the para-substituted bridges ligands of 1 and 3-8 but positive (ferromagnetic exchange) across the meta-substituted bridging ligands of 2 and 9. (2) J decreases in magnitude dramatically as the bridging ligand conformation changes from planar to twisted (compare 3 and 4, or 6 and 8). These observations are consistent with a spin-polarization mechanism for the exchange interaction, propagated across the pi-system of the bridging ligand by via overlap of bridging ligand p(pi) orbitals with the d(pi) magnetic orbitals of the metals. The EPR spectrum of 9 is characteristic of a quartet species and shows weak Deltam(s) = 2 and Deltam(s) = 3 transitions at one-half and one-third, respectively, of the field strength of the principal Deltam(s) = 1 component.

Infrared absorption of 1-chloro-2-methyl-2-propyl [⋅C(CH3)2CH2Cl] and 2-chloro-2-methylpropyl [⋅CH2C(CH3)2Cl] radicals produced in the addition reactions of Cl with isobutene (i-C4H8) in solid para-hydrogen.

PubMed

Chou, Ching-Yin; Lee, Yuan-Pern

2016-10-07

The addition reactions of chlorine atom with isobutene (i-C 4 H 8 ) in solid para-hydrogen (p-H 2 ) were investigated with infrared (IR) absorption spectra. When a p-H 2 matrix containing Cl 2 and isobutene was irradiated with ultraviolet light at 365 nm, intense lines in a set at 534.5, 1001.0, 1212.9, 1366.0, 2961.6, and 2934.7 cm -1 , and several weaker others due to the 1-chloro-2-methyl-2-propyl radical, ⋅ C(CH 3 ) 2 CH 2 Cl, and those in a second set including intense ones at 642.7, 799.2, 1098.2, 1371.8, and 3027.3 cm -1 due to the 2-chloro-2-methylpropyl radical, ⋅ CH 2 C(CH 3 ) 2 Cl, appeared; the ratio of ⋅ C(CH 3 ) 2 CH 2 Cl to ⋅ CH 2 C(CH 3 ) 2 Cl was approximately (3 ± 1):1. The observed wavenumbers and relative intensities agree with the vibrational wavenumbers and IR intensities predicted with the B3PW91/aug-cc-pVTZ method. That the Cl atom adds to both carbons of the C=C bond of isobutene with the terminal site slightly favored is consistent with the energies of products predicted theoretically, but is in contrast to the reaction of Cl + propene in solid p-H 2 in which the addition of Cl to mainly the central C atom was previously reported. The role of the p-H 2 matrix in affecting the reaction paths is discussed. Absorption lines of the complex i-C 4 H 8 ⋅Cl 2 and the dichloro-product anti-1,2-dichloro-2-methylpropane, a-CH 2 ClCCl(CH 3 ) 2 , are also characterized.

Ligand-to-ligand charge-transfer transitions of platinum(II) complexes with arylacetylide ligands with different chain lengths: spectroscopic characterization, effect of molecular conformations, and density functional theory calculations.

PubMed

Tong, Glenna So Ming; Law, Yuen-Chi; Kui, Steven C F; Zhu, Nianyong; Leung, King Hong; Phillips, David Lee; Che, Chi-Ming

2010-06-11

The complexes [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)R}](+) (n = 1: R = alkyl and aryl (Ar); n = 1-3: R = phenyl (Ph) or Ph-N(CH(3))(2)-4; n = 1 and 2, R = Ph-NH(2)-4; tBu(3)tpy = 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) and [Pt(Cl(3)tpy)(C[triple bond]CR)](+) (R = tert-butyl (tBu), Ph, 9,9'-dibutylfluorene, 9,9'-dibutyl-7-dimethyl-amine-fluorene; Cl(3)tpy = 4,4',4''-trichloro-2,2':6',2''-terpyridine) were prepared. The effects of substituent(s) on the terpyridine (tpy) and acetylide ligands and chain length of arylacetylide ligands on the absorption and emission spectra were examined. Resonance Raman (RR) spectra of [Pt(tBu(3)tpy)(C[triple bond]CR)](+) (R = n-butyl, Ph, and C(6)H(4)-OCH(3)-4) obtained in acetonitrile at 298 K reveal that the structural distortion of the C[triple bond]C bond in the electronic excited state obtained by 502.9 nm excitation is substantially larger than that obtained by 416 nm excitation. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations on [Pt(H(3)tpy)(C[triple bond]CR)](+) (R = n-propyl (nPr), 2-pyridyl (Py)), [Pt(H(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)Ph}](+) (n = 1-3), and [Pt(H(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+)/+H(+) (n = 1-3; H(3)tpy = nonsubstituted terpyridine) at two different conformations were performed, namely, with the phenyl rings of the arylacetylide ligands coplanar ("cop") with and perpendicular ("per") to the H(3)tpy ligand. Combining the experimental data and calculated results, the two lowest energy absorption peak maxima, lambda(1) and lambda(2), of [Pt(Y(3)tpy)(C[triple bond]CR)](+) (Y = tBu or Cl, R = aryl) are attributed to (1)[pi(C[triple bond]CR)-->pi*(Y(3)tpy)] in the "cop" conformation and mixed (1)[d(pi)(Pt)-->pi*(Y(3)tpy)]/(1)[pi(C[triple bond]CR)-->pi*(Y(3)tpy)] transitions in the "per" conformation. The lowest energy absorption peak lambda(1) for [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-H-4}](+) (n = 1-3) shows a redshift with increasing chain length. However, for [Pt(tBu(3)tpy){C[triple bond]C(C6H4C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+) (n = 1-3), lambda(1) shows a blueshift with increasing chain length n, but shows a redshift after the addition of acid. The emissions of [Pt(Y(3)tpy)(C[triple bond]CR)](+) (Y = tBu or Cl) at 524-642 nm measured in dichloromethane at 298 K are assigned to the (3)[pi(C[triple bond]CAr)-->pi*(Y(3)tpy)] excited states and mixed (3)[d(pi)(Pt)-->pi*(Y(3)tpy)]/(3)[pi(C[triple bond]C)-->pi*(Y(3)tpy)] excited states for R = aryl and alkyl groups, respectively. [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+) (n = 1 and 2) are nonemissive, and this is attributed to the small energy gap between the singlet ground state (S(0)) and the lowest triplet excited state (T(1)).

Axial zero-field splitting in mononuclear Co(ii) 2-N substituted N-confused porphyrin: Co(2-NC3H5-21-Y-CH2C6H4CH3-NCTPP)Cl (Y = o, m, p) and Co(2-NC3H5-21-CH2C6H5-NCTPP)Cl.

PubMed

Lai, Ya-Yuan; Chang, Yu-Chang; Chen, Jyh-Horung; Wang, Shin-Shin; Tung, Jo-Yu

2016-03-21

The inner C-benzyl- and C-o-xylyl (or m-xylyl, p-xylyl)-substituted cobalt(ii) complexes of a 2-N-substituted N-confused porphyrin were synthesized from the reaction of 2-NC3H5NCTPPH (1) and CoCl2·6H2O in toluene (or o-xylene, m-xylene, p-xylene). The crystal structures of diamagnetic chloro(2-aza-2-allyl-5,10,15,20-tetraphenyl-21-hydrogen-21-carbaporphyrinato-N,N',N'')zinc(ii) [Zn(2-NC3H5-21-H-NCTPP)Cl; 3 ] and paramagnetic chloro(2-aza-2-allyl-5,10,15,20-tetraphenyl-21-benzyl-21-carbaporphyrinato-N,N',N'')cobalt(ii) [Co(2-NC3H5-21-CH2C6H5NCTPP)Cl; 7], and chloro(2-aza-2-allyl-5,10,15,20-tetraphenyl-21-Y-xylyl-21-carbaporphyrinato-N,N',N'')cobalt(ii) [Co(2-NC3H5-21-Y-CH2C6H4CH3NCTPP)Cl] [Y = o (8), m (9), p (10)] were determined. The coordination sphere around the Zn(2+) (or Co(2+)) ion in 3 (or 7-10) is a distorted tetrahedron (DT). The free energy of activation at the coalescence temperature Tc for the exchange of phenyl ortho protons o-H (26) with o-H (22) in 3 in a CDCl3 solvent is found to be ΔG = 61.4 kJ mol(-1) through (1)H NMR temperature-dependent measurements. The axial zero-field splitting parameter |D| was found to vary from 35.6 cm(-1) in 7 (or 30.7 cm(-1) in 8) to 42.0 cm(-1) in 9 and 46.9 cm(-1) in 10 through paramagnetic susceptibility measurements. The magnitude of |D| can be related to the coordination sphere at the cobalt sites.

Unimolecular HCl and HF elimination reactions of 1,2-dichloroethane, 1,2-difluoroethane, and 1,2-chlorofluoroethane: assignment of threshold energies.

PubMed

Duncan, Juliana R; Solaka, Sarah A; Setser, D W; Holmes, Bert E

2010-01-21

The recombination of CH(2)Cl and CH(2)F radicals generates vibrationally excited CH(2)ClCH(2)Cl, CH(2)FCH(2)F, and CH(2)ClCH(2)F molecules with about 90 kcal mol(-1) of energy in a room temperature bath gas. New experimental data for CH(2)ClCH(2)F have been obtained that are combined with previously published studies for C(2)H(4)Cl(2) and C(2)H(4)F(2) to define reliable rate constants of 3.0 x 10(8) (C(2)H(4)F(2)), 2.4 x 10(8) (C(2)H(4)Cl(2)), and 1.9 x 10(8) (CH(2)ClCH(2)F) s(-1) for HCl and HF elimination. The product branching ratio for CH(2)ClCH(2)F is approximately 1. These experimental rate constants are compared to calculated statistical rate constants (RRKM) to assign threshold energies for HF and HCl elimination. The calculated rate constants are based on transition-state models obtained from calculations of electronic structures; the energy levels of the asymmetric, hindered, internal rotation were directly included in the state counting to obtain a more realistic measure for the density of internal states for the molecules. The assigned threshold energies for C(2)H(4)F(2) and C(2)H(4)Cl(2) are both 63 +/- 2 kcal mol(-1). The threshold energies for CH(2)ClCH(2)F are 65 +/- 2 (HCl) and 63 +/- 2 (HF) kcal mol(-1). These threshold energies are 5-7 kcal mol(-1) higher than the corresponding values for C(2)H(5)Cl or C(2)H(5)F, and beta-substitution of F or Cl atoms raises threshold energies for HF or HCl elimination reactions. The treatment presented here for obtaining the densities of states and the entropy of activation from models with asymmetric internal rotations with high barriers can be used to judge the validity of using a symmetric internal-rotor approximation for other cases. Finally, threshold energies for the 1,2-fluorochloroethanes are compared to those of the 1,1-fluorochloroethanes to illustrate substituent effects on the relative energies of the isomeric transition states.

Synthesis and X-ray crystal structures of heavy-metal complexes of 1,5,9,13-tetrathiacyclohexadecane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setzer, W.N.; Tang, Yaping; Grant, G.J.

1991-09-18

Heavy-metal complexes of the macrocyclic tetrathioether 1,5,9,13-tetrathiacyclohexadecane (16S4) have been prepared by reaction of the ligand with the appropriate heavy-metal salts. The complexes [Hg(16S4)](ClO[sub 4])[sub 2], [Cd(16S4)](ClO[sub 4])[sub 2], and (16S4)(HgCl[sub 2])[sub 2] have been synthesized and characterized. Single-crystal X-ray structural studies have been carried out on [Hg(16S4)](ClO[sub 4])[sub 2] and [Cd(16S4)](ClO[sub 4])[sub 2]. Crystal data for [Hg(16S4)](ClO[sub 4])[sub 2]: C[sub 12]H[sub 24]S[sub 4]HgCl[sub 2]O[sub 8]; monoclinic space group C2/c; a = 10.033 (3), b = 13.421 (4), c = 15.960 (4) [angstrom]; [beta] = 96.48 (2)[degree]; Z = 4; R = 0.051. Crystal data for [Cd(16S4)](ClO[sub 4])[sub 2]: C[submore » 12]H[sub 24]S[sub 4]CdCl[sub 2]O[sub 8]; triclinic space group P[bar I]; a = 8.346 (2), b = 8.349 (3), c = 8.688 (2) [angstrom]; [alpha] = 69.87 (2), [beta] = 68.97 (2), [gamma] = 82.33 (2)[degree]; Z = 1; R = 0.043. Molecular mechanics calculations have been carried out on the 16S4 ligand, and the lowest energy conformation is a quadrangular [4444] conformation with the sulfur atoms occupying the corners (exodentate) of the quadrangle.« less

Hydrogen Isotope Fractionation during the Biodegradation of 1,2-Dichloroethane: Potential for Pathway Identification Using a Multi-element (C, Cl, and H) Isotope Approach.

PubMed

Palau, Jordi; Shouakar-Stash, Orfan; Hatijah Mortan, Siti; Yu, Rong; Rosell, Monica; Marco-Urrea, Ernest; Freedman, David L; Aravena, Ramon; Soler, Albert; Hunkeler, Daniel

2017-09-19

Even though multi-element isotope fractionation patterns provide crucial information with which to identify contaminant degradation pathways in the field, those involving hydrogen are still lacking for many halogenated groundwater contaminants and degradation pathways. This study investigates for the first time hydrogen isotope fractionation during both aerobic and anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) using five microbial cultures. Transformation-associated isotope fractionation values (ε bulk H ) were -115 ± 18‰ (aerobic C-H bond oxidation), -34 ± 4‰ and -38 ± 4‰ (aerobic C-Cl bond cleavage via hydrolytic dehalogenation), and -57 ± 3‰ and -77 ± 9‰ (anaerobic C-Cl bond cleavage via reductive dihaloelimination). The dual-element C-H isotope approach (Λ C-H = Δδ 2 H/Δδ 13 C ≈ ε bulk H /ε bulk C , where Δδ 2 H and Δδ 13 C are changes in isotope ratios during degradation) resulted in clearly different Λ C-H values: 28 ± 4 (oxidation), 0.7 ± 0.1 and 0.9 ± 0.1 (hydrolytic dehalogenation), and 1.76 ± 0.05 and 3.5 ± 0.1 (dihaloelimination). This result highlights the potential of this approach to identify 1,2-DCA degradation pathways in the field. In addition, distinct trends were also observed in a multi- (i.e., Δδ 2 H versus Δδ 37 Cl versus Δδ 13 C) isotope plot, which opens further possibilities for pathway identification in future field studies. This is crucial information to understand the mechanisms controlling natural attenuation of 1,2-DCA and to design appropriate strategies to enhance biodegradation.

Speciation of inorganic and organolead compounds by gas chromatography-atomic absorption spectrometry and the determination of lead species after pre-concentration onto diphenylthiocarbazone-anchored polymeric microbeads

NASA Astrophysics Data System (ADS)

Salih, Bekir

2000-07-01

Poly(EGDMA-HEMA) microbeads were prepared by suspension copolymerization of ethyleneglycol dimethacrylate (EGDMA) and hydroxyethylmethacrylate (HEMA) using poly(vinylalcohol), benzoyl peroxide and toluene as the stabilizer, the initiator, and the diluent, respectively. A chelating ligand, diphenylthiocarbazone (dithizone), was then attached. The microbeads were characterized by FT-IR and elemental analysis. The affinity microbeads containing 118.9 μmol dithizone g -1 polymer were used in the adsorption/desorption of some selected lead species, Pb(II), (CH 3) 2PbCl 2, (C 2H 5) 2PbCl 2, (CH 3) 3PbCl, and (C 2H 5) 3PbCl from aqueous media containing different amounts of these species (5-200 mg l -1) at different pH values, 2.0-8.0. Adsorption rates were high, and adsorption equilibrium was reached in approximately 45 min. The detection limits of the lead species onto the dithizone-anchored affinity microbeads from solutions containing a single species was 0.28 ng ml -1 for Pb(II), 0.12 ng ml -1 for (CH 3) 3PbCl, 0.24 ng ml -1 for (C 2H 5) 3PbCl, 0.18 ng ml -1 for (CH 3) 2PbCl 2 and 0.30 ng ml -1 for (C 2H 5) 2PbCl 2 on a weight basis for lead. The same behavior was observed during competitive adsorption that is adsorption from a mixture. The affinity order of the lead species was Pb(II)>(CH 3) 2PbCl 2>(CH 3) 3PbCl>(C 2H 5) 3PbCl>(C 2H 5) 2PbCl 2 for competitive adsorption. Dithizone-anchored microbeads were found to be suitable for repeated use of more than five cycles, without noticeable loss of adsorption capacity. For the speciation of organolead compounds, ionic alkyllead compounds were derivatized by n-butyl Grignard reagent and the speciation was performed using a gas chromatography-atomic absorption spectrometry coupled system. Detection limits were improved at least 180-fold with this preconcentration approach using the dithizone-anchored microbeads.

Molecular structure stability of short-chain chlorinated paraffins (SCCPs): Evidence from lattice compatibility and Simha-Somcynsky theories

NASA Astrophysics Data System (ADS)

Yumak, A.; Boubaker, K.; Petkova, P.; Yahsi, U.

2015-10-01

In is known that short-chain chlorinated paraffins (SCCPs) are highly complex technical mixtures of polychlorinated n-alkanes with single chlorine content. Due to their physical properties (viscosity, flame resistance) they are used in many different applications, such as lubricant additives, metal processing, leather fat-liquoring, plastics softening, PVC plasticizing and flame retardants in paints, adhesives and sealants. SCCPs are studied here in terms of processing-linked molecular structure stability, under Simha and Somcynsky-EOS theory calculations and elements from Simha-Somcynsky-related Lattice Compatibility Theory. Analyses were carried out on 1-chloropropane, 2-chloropropane, 1-chlorobutane, 2-chlorobutane, 1-chloro 2-methylane, and 2-chloro 2-methylane as (SCCPs) universal representatives. This paper gives evidence to this stability and reviews the current state of knowledge and highlights the need for further research in order to improve future (SCCPs) monitoring efforts.

Monitoring structural transformations in crystals. 7. 1-Chloroanthracene and its photodimer.

PubMed

Turowska-Tyrk, Ilona; Grześniak, Karolina

2004-02-01

Crystals of the 1-chloroanthracene photodimer, viz. trans-bi(1-chloro-9,10-dihydro-9,10-anthracenediyl), C(28)H(18)Cl(2), were obtained from the solid-state [4+4]-photodimerization of the monomer, C(14)H(9)Cl, followed by recrystallization. The symmetry of the product molecules is defined by the orientation of the reactant molecules in the crystal. The mutual orientation parameters calculated for adjacent monomers explain the reactivity of the compound. The molecules in the crystal of the monomer and the recrystallized photodimer pack differently and the photodimer has crystallographically imposed inversion symmetry.

Hot-corrosion of AISI 1020 steel in a molten NaCl/Na2SO4 eutectic at 700°C

NASA Astrophysics Data System (ADS)

Badaruddin, Mohammad; Risano, Ahmad Yudi Eka; Wardono, Herry; Asmi, Dwi

2017-01-01

Hot-corrosion behavior and morphological development of AISI 1020 steel with 2 mg cm-2 mixtures of various NaCl/Na2SO4 ratios at 700°C were investigated by means of weight gain measurements, Optical Microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The weight gain kinetics of the steel with mixtures of salt deposits display a rapid growth rates, compared with the weight gain kinetics of AISI 1020 steel without salt deposit in dry air oxidation, and follow a steady-state parabolic law for 49 h. Chloridation and sulfidation produced by a molten NaCl/Na2SO4 on the steel induced hot-corrosion mechanism attack, and are responsible for the formation of thicker scale. The most severe corrosion takes place with the 70 wt.% NaCl mixtures in Na2SO4. The typical Fe2O3 whisker growth in outer part scale was attributed to the FeCl3 volatilization. The formation of FeS in the innermost scale is more pronounced as the content of Na2SO4 in the mixture is increased.

Novel types of tetra-, hexa-, octa-, and dodecanuclear silver clusters containing (2,7-Di-tert-butylfluoren-9-ylidene)methanedithiolate.

PubMed

Vicente, José; González-Herrero, Pablo; García-Sánchez, Yolanda; Jones, Peter G

2009-03-02

The reaction of AgClO(4) with piperidinium 2,7-di-tert-butyl-9H-fluorene-9-carbodithioate (pipH)[S(2)C(t-Bu-Hfy)] (1) (t-Bu-Hfy = 2,7-di-tert-butylfluoren-9-yl) afforded [Ag(n){S(2)C(t-Bu-Hfy)}(n)] (2), which reacted with phosphines to give [Ag{S(2)C(t-Bu-Hfy)}L(2)] [L = PPh(3) (3a); L(2) = bis(diphenylphosphino)ethane (dppe, 3b), 1,1'-bis(diphenylphosphino)ferrocene (dppf, 3c). By reacting complex 2 with AgClO(4) and piperidine in a 1:1:1 molar ratio, the dodecanuclear cluster [Ag(12){S(2)C(t-Bu-fy)}(6)] (4) (t-Bu-fy = 2,7-di-tert-butylfluoren-9-ylidene) was obtained. Compound 4 can also be directly prepared from the reaction of 1 with AgClO(4) and piperidine in a 1:2:1 molar ratio. The reactions of 1 with AgClO(4), phosphines, and piperidine afforded the compounds [Ag(6){S(2)C(t-Bu-fy)}(3)L(5)] [1:2:2:1 molar ratio; L = PPh(3) (5a), P(p-To)(3) (5b)], [Ag(4){S(2)C(t-Bu-fy)}(2)(dppf)(2)] (6) (1:2:1:1 molar ratio), [Ag(n){S(2)C(t-Bu-fy)}(n/2){P(i-Pr)(3)}(n)] (7) (1:2:2:1 molar ratio), or [Ag(8){S(2)C(t-Bu-fy)}(4){P(i-Pr)(3)}(4)] (8) (1:2:1:1 molar ratio). Complexes 5a,b, 6, 7, and 8 can be also obtained by reacting 4 with the corresponding phosphine in the appropriate molar ratio. The crystal structures of 4, 5b, and 8 have been determined by X-ray diffraction studies. The nuclearity of complex 6 was established from its (31)P{(1)H} NMR data, which reveal a very fast dynamic process leading to an average coupling of each of the P atoms of the dppf ligands with four Ag atoms.

Stereoselective synthesis of novel thioglycosyl heterocycles

NASA Astrophysics Data System (ADS)

El Ashry, El Sayed H.; Awad, Laila F.; Al Moaty, Mohamed N. Abd; Ghabbour, Hazem A.; Barakat, Assem

2018-01-01

In this work, the synthesis of novel 1,2,4-triazole thioglycoside heterocycles 4, 5, and 8 were achieved by the reaction of 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose (2) and galactopyranose (3) with 4-((4-arylidene)amino)-5-methyl-1,2,4-triazole-3-thiol derivatives 1 and 6 in the presence of boron trifluoride etherate (BF3·Et2O) as a promoter under nitrogen in CH2Cl2. Exclusive β-stereoselectivity of the formed glycosidic bond was confirmed by X-ray analysis of 4 as well as its spectral data. Different stereoselectivities were observed when the acceptor 9, having an ortho phenolic OH group, was coupled with the donors 2 or 3, under the same reaction conditions. Similarly, treatment of a mixture of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (16) and the thiol acceptors 1 and 15 afforded the β-thioribofuranosides 17 and 18, respectively. The β-stereoselectivity of the reaction was confirmed by 1H, 13C, 1Hsbnd 1H 2D, and 1Hsbnd 13C 2D NMR spectral analysis.

Chemistry of 1,1,2,2,9,9,10,10-octafluoro-[2,2]-paracyclophane: Its synthesis and reactions

NASA Astrophysics Data System (ADS)

Duan, Jian-Xin

This dissertation describes the first example of the synthesis of 1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophane (AF4) under non-high-dilution conditions. Under very mild reaction conditions, bis-p-(chlorodifluoromethyl)benzene (TFPX dichloride) and its derivatives reacted with Zn dust in N,N-dimethyl acetamide (DMA) (Zinc method) affording the corresponding AF4 and its derivatives in moderate to good yields. Purification of products was also studied and an efficient purification process was developed. A new and very cheap method for preparation of TFPX dichloride is also disclosed. Using the very cheap fluorinating reagent, anhydrous hydrogen fluoride (AHF), 1,4-bis(trichloromethyl)benezene or its derivatives were converted to TFPX and its derivatives in high yields (F/Cl exchange reaction). With the success of the Zinc method and F/Cl exchange reaction, highly pure AF4 thus can be provided to the semiconductor industry and academy research scientists in large quantity and at a very low price. Starting from AF4, numerous AF4 derivatives were synthesized using convenient reaction conditions. Reaction of AF4 with fuming nitric acid at room temperature gave mono-nitroAF4 in almost quantitative yield. Reduction of the mono-nitroAF4 with iron powder in the presence of HCl in alcoholic solvent gave the aminoAF4 in 90% yield. Via the diazonium salt intermediate, iodoAF4 was also obtained in good yield. Under similar reaction conditions, disubstituted AF4 derivatives were also prepared in good yields. Heating a mixture of AF4, trifluoroacetyl peroxide and dichloromethane gave the trifluoromethylated dimeric AF4 as a mixture of diastereomers. When these products were heated to 170--180°C in the presence of I 2, 4-trifluoromethyl-AF4 was obtained in almost 87% yield. X-ray structural analysis showed that the C-C bond connecting the two cyclophane moieties to be longer than the normal C-C bond. Kinetic studies, conducted in the presence of excess amount of hydrogen donor, showed this bond to be quite weak. Oxidation of AF4 with HIO3 in the presence of catalytic amount of H2SO4 in trifluoroacetic acid gave AF4 quinone in one step. AF4 quinone can be easily reduced to the hydroquinone by Na 2S2O4 aqueous solution.

Iodine bonding stabilizes iodomethane in MIDAS pesticide. Theoretical study of intermolecular interactions between iodomethane and chloropicrin.

PubMed

Glaser, Rainer; Prugger, Kaitlan

2012-02-22

The results are reported of a theoretical study of iodomethane (H(3)C-I, 1) and chloropicrin (Cl(3)C-NO(2), 2), of the heterodimers 3-6 formed by aggregation of 1 and 2, and of their addition products 7 and 8 and their possible fragmentation reactions to 9-18. Mixtures of iodomethane and chloropicrin are not expected to show chemistry resulting from their reactions with each other. The structures and stabilities are discussed of the iodine-bonded molecular aggregates (IBMA) 3 and 4 and of the hydrogen- and iodine-bonded molecular aggregates (IHBMA) 5 and 6. The mixed aggregates 3-5 are bound on the free enthalpy surface relative to the homodimers of 1 and 2, and the IBMA structures 3 and 4 are most stable. This result suggests that the mixture of chloropicrin and iodomethane in the pesticide Midas is a good choice to reduce the volatility of iodomethane because of thermodynamically stabilizing iodine bonding.

Optical and magnetic properties for metal halide-based organic-inorganic layered perovskites

NASA Astrophysics Data System (ADS)

Shikoh, Eiji; Ando, Yasuo; Era, Masanao; Miyazaki, Terunobu

2001-05-01

Layered perovskites (RNH 3) 2CuCl 4, where R was methyl-benzene C 6H 5-CH 2, 1-methyl-naphthalene 1-C 10H 9-CH 2, 1-propyl-naphthalene 1-C 10H 9-O(CH 2) 3 and 1-butyl-naphthalene 1-C 10H 9-O(CH 2) 4, were synthesized. These complexes showed ferromagnetism, with different Curie temperatures, TC, depending on the structure of the molecule. The change of TC by taking into account the overlap of the electronic states between the organic and the inorganic layers were discussed.

INFRARED STUDY OF UV/EUV IRRADIATION OF NAPHTHALENE IN H2O+NH3 ICE

NASA Astrophysics Data System (ADS)

Chen, Y.-J.; Nuevo, M.; Yeh, F.-C.; Yih, T.-S.; Sun, W.-H.; Ip, W.-H.; Fung, H.-S.; Lee, Y.-Y.; Wu, C.-Y. R.

We have carried out photon irradiation study of naphthalene (C10H8), the smallest polycyclic aromatic hydrocarbon (PAH) in water and ammonia ice mixtures. Photons provided by a synchrotron radiation light source in two broad-band energy ranges in the ultraviolet/near extreme ultraviolet (4-20 eV) and the extreme ultraviolet (13-45 eV) ranges were used for the irradiation of H2O+NH3+C10H8 = 1:1:1 ice mixtures at 15K. We could identify several photo-products, namely CH4, C2H6, C3H8, CO, CO2, HNCO, OCN-, and probably quinoline (C9H7N) and phenanthridine (C13H9N). We found that the light hydrocarbons are preferably produced for the ice mixture subjected to 4-20 eV photons. However, the production yields of CO, CO2, and OCN- species seem to be higher for the mixture subjected to EUV photons (13-45 eV). Therefore, naphthalene and its photo-products appear to be more efficiently destroyed when high energy photons (E > 20 eV) are used. This has important consequences on the photochemical evolution of PAHs in astrophysical environments.

Genetic Exclusion in Bacteriophage T4.

DTIC Science & Technology

1987-01-01

1942) as "interference" between various coliphages , was shown by Delbruck and Bailey (1946) to be the inability of superinfecting phage to contribute... water : 5.8 g Na IPO , 3.0 2 4 g KH PO , 0.5 g NaCl, 1.0 g NH Cl, and the pH adjusted to 2 4 4 o 6.8 to 7.0. All media were autoclaved, cooled to 55 C...0.5M Tris), once with a 1:1 mixture of phenol and chloroform (1/24 isoamyl alcohol) then thrice iith an equal volume of water saturated ether. After

Synthesis, structural characterization, and electrochemical properties of dinuclear Ni/Mn model complexes for the active site of [NiFe]-hydrogenases.

PubMed

Song, Li-Cheng; Li, Jia-Peng; Xie, Zhao-Jun; Song, Hai-Bin

2013-10-07

Four new dinuclear Ni/Mn model complexes RN(PPh2)2Ni(μ-SEt)2(μ-Cl)Mn(CO)3 (7, R = p-MeC6H4CH2; 8, R = EtO2CCH2) and RN(PPh2)2Ni(μ-SEt)2(μ-Br)Mn(CO)3 (9, R = p-MeC6H4CH2; 10, R = EtO2CCH2) have been prepared via the four separated step-reactions involving six new precursors RN(PPh2)2 (1, R = p-MeC6H4CH2; 2, R = EtO2CCH2), RN(PPh2)2NiCl2 (3, R = p-MeC6H4CH2; 4, R = EtO2CCH2), and RN(PPh2)2Ni(SEt)2 (5, R = p-MeC6H4CH2; 6, R = EtO2CCH2). The Et3N-assisted aminolysis of Ph2PCl with p-MeC6H4CH2NH2 or EtO2CCH2NH2·HCl in CH2Cl2 gave the azadiphosphine ligands 1 and 2 in 38% and 53% yields, whereas the coordination reaction of 1 or 2 with NiCl2·6H2O in CH2Cl2/MeOH afforded the mononuclear Ni dichloride complexes 3 and 4 in 59% and 78% yields, respectively. While thiolysis of 3 or 4 with EtSH under the assistance of Et3N in CH2Cl2 produced the mononuclear Ni dithiolate complexes 5 and 6 in 64% and 68% yields, further treatment of 5 and 6 with Mn(CO)5Cl or Mn(CO)5Br resulted in formation of the dinuclear Ni/Mn model complexes 7-10 in 31-73% yields. All the new compounds 1-10 have been structurally characterized, while model complexes 7 and 9 have been found to be catalysts for HOAc proton reduction to hydrogen under CV conditions.

Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: Detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells

NASA Astrophysics Data System (ADS)

Jagadeesh, M.; Kalangi, Suresh K.; Sivarama Krishna, L.; Reddy, A. Varada

2014-01-01

Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1 = 2.1228, g2 = 2.0706 and g3 = 2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 μM.

Intrinsic viscosity of binary gum mixtures with xanthan gum and guar gum: Effect of NaCl, sucrose, and pH.

PubMed

Bak, J H; Yoo, B

2018-05-01

The intrinsic viscosity ([η]) values of binary gum mixtures with xanthan gum (XG) and guar gum (GG) mixed with NaCl and sucrose at different concentrations as well as in the presence of different pH levels were examined in dilute solution as a function of XG/GG mixing ratio (100/0, 75/25, 50/50, and 0/100). Experimental values of concentration (C) and relative viscosity (η rel ) or specific viscosity (η sp ) of gums in dilute solution were fitted to five models to determine [η] values of binary gum mixtures including individual gums. A [η] model (η rel =1+[η]C) of Tanglertpaibul and Rao is recommended as the best model to estimate [η] values for the binary gum mixtures with XG and GG as affected by NaCl, sucrose, and pH. Overall, the synergistic interaction of XG-GG mixtures in the presence of NaCl and sucrose showed a greatly positive variation between measured and calculated values of [η]. In contrast, the binary gum mixtures showed synergy only under an acidic condition (pH3). These results suggest that the NaCl and sucrose addition or acidic condition appears to affect the intermolecular interaction occurred between XG and GG at different gum mixing ratios. Copyright © 2018 Elsevier B.V. All rights reserved.

Atomic layer deposition of zirconium silicate films using zirconium tetra-tert-butoxide and silicon tetrachloride

NASA Astrophysics Data System (ADS)

Kim, Won-Kyu; Kang, Sang-Woo; Rhee, Shi-Woo

2003-09-01

A new precursor combination (SiCl4 and Zr(OtC4H9)4) was used to deposit Zr silicate with Zr(OtC4H9)4 as a zirconium source and oxygen source at the same time. SiCl4 and Zr(OtC4H9)4 have higher vapor pressures than their counterpart, ZrCl4 and tetra-n-butyl orthosilicate (TBOS), and it was expected that the cycle time would be shorter. The deposition temperature of the new combination was about 150 °C lower than that of ZrCl4 and TBOS. The film was zirconium rich while it was silicon rich with ZrCl4 and TBOS. Growth rate (nm/cycle), composition ratio [Zr/(Zr+Si)], and chlorine impurity were decreased with increasing deposition temperature from 125 to 225 °C. The composition ratio of the film deposited at 225 °C was 0.53 and the chlorine content was about 0.4 at. %. No carbon was detected by x-ray photoelectron spectroscopy.

Copper(I) Complexes of N-(2-{[(2E)-2-(4-Nitrobenzylidenyl)Hydrazinyl]Carbonyl}Phenyl)Benzamide and Triphenylphosphine: Synthesis, Characterization and Luminescence Properties.

PubMed

Chavan, S S; Pawal, S B; More, M S; Willis, A C

2016-11-01

Copper(I) complexes of the formula [Cu(L)(PPh 3 ) 2 ]X (1-4) (X = Cl(1), ClO 4 (2), BF 4 (3) and PF 6 (4)) [where L = N-(2-{[(2E)-2-(4-nitrobenzylidenyl)hydrazinyl]carbonyl}phenyl)benzamide; PPh 3  = triphenylphosphine] have been prepared by the condensation of N-[2-(hydrazinocarbonyl)phenyl]benzamide with 4-nitrobenzaldehyde followed by the reaction with CuCl, [Cu(MeCN) 4 ]ClO 4 , [Cu(MeCN) 4 ]BF 4 and [Cu(MeCN) 4 ]PF 6 in presence of triphenylphosphine as a coligand. Complexes 1-4 were then characterized by elemental analyses, FTIR, UV-visible and 1 H NMR spectroscopy. Mononuclear copper(I) complexes 1-4 were formed with L in its keto form by involvement of azomethine nitrogen and the carbonyl oxygen along with two PPh 3 groups. A single crystal X-ray diffraction study of the representative complex [(Cu(L)(PPh 3 ) 2 ]CIO 4 (2) reveals a distorted tetrahedral geometry around Cu(I). Crystal data of (2): space group = C2/c, a = 42.8596 (9) Å, b = 14.6207 (3) Å, c = 36.4643 (7) Å, V = 20,653.7 (7) Å 3 , Z = 16. Complexes 1-4 exhibit quasireversible redox behaviour corresponding to a Cu(I)/Cu(II) couple. All complexes show blue-green emission as a result of fluorescence from an intra-ligand charge transition (ILCT), ligand to ligand charge transfer transition (LLCT) or mixture of both. Significant increase in size of the counter anion shows marked effect on quantum efficiency and lifetime of the complexes in solution.

Structure-activity relationship of cyclic peptide penta-c[Asp-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys]-NH(2) at the human melanocortin-1 and -4 receptors: His(6) substitution.

PubMed

Cheung, Adrian Wai-Hing; Danho, Waleed; Swistok, Joseph; Qi, Lida; Kurylko, Grazyna; Rowan, Karen; Yeon, Mitch; Franco, Lucia; Chu, Xin-Jie; Chen, Li; Yagaloff, Keith

2003-04-07

A series of MT-II related cyclic peptides, based on potent but non-selective hMC4R agonist (Penta-c[Asp-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys]-NH(2)) was prepared in which His(6) residue was systematically substituted. Two of the most interesting peptides identified in this study are Penta-c[Asp-5-ClAtc-DPhe-Arg-Trp-Lys]-NH(2) and Penta-c[Asp-5-ClAtc-DPhe-Cit-Trp-Lys]-NH(2) which are potent hMC4R agonists and are either inactive or weak partial agonists (not tested for their antagonist activities) in hMC1R, hMC3R and hMC5R agonist assays.

Effect of Sodium Chloride and pH on Enterotoxin C Production

PubMed Central

Genigeorgis, Constantin; Foda, Mohamed S.; Mantis, Antony; Sadler, Walter W.

1971-01-01

Growth and production of enterotoxin C by Staphylococcus aureus strain 137 in 3% + 3% protein hydrolysate powder N-Z Amine NAK broths with 0 to 12% NaCl and an initial pH of 4.00 to 9.83 were studied during an 8-day incubation period at 37 C. Growth was initiated at pH values as low as 4.00 and as high as 9.83 at 0% salt level as long as the inoculum contained at least 108 cells per ml. Rate of growth decreased as the NaCl concentration was increased gradually to 12%. Enterotoxin C was produced in broths inoculated with 108 cells per ml and above and having initial pH ranges of 4.00 to 9.83, 4.40 to 9.43, 4.50 to 8.55 and respective NaCl concentrations of 0, 4, and 8%. In the presence of 10% NaCl, the pH range supporting enterotoxin C production was 5.45 to 7.30 for an inoculum level of 108 cells per ml and 6.38 to 7.30 for 3.6 × 106 cells per ml. In repeated experiments in which the inoculum contained 108 cells per ml, we failed to demonstrate enterotoxin C production in broths with 12% NaCl and a pH range of 4.50 to 8.55 and concentrated up to 14 times. The effect of NaCl on enterotoxin C production followed the same pattern as its effect on enterotoxin B production. As the concentration of NaCl increased from 0 to 10%, yields of enterotoxin B and C decreased to undetectable amounts. PMID:5574320

Synthesis and structural and photoswitchable properties of novel chiral host molecules: axis chiral 2,2'-dihydroxy-1,1'-binaphthyl-appended stiff-stilbene.

PubMed

Shimasaki, Toshiaki; Kato, Shin-ichiro; Ideta, Keiko; Goto, Kenta; Shinmyozu, Teruo

2007-02-16

Novel photoswitchable chiral hosts having an axis chiral 2,2'-dihydroxy-1,1'-binaphthyl (BINOL)-appended stiff-stilbene, trans-(R,R)- and -(S,S)-1, were synthesized by palladium-catalyzed Suzuki-Miyaura coupling and low-valence titanium-catalyzed McMurry coupling as key steps, and they were fully characterized by various NMR spectral techniques. The enantiomers of trans-1 showed almost complete mirror images in the CD spectra, where two split Cotton effects (exciton coupling) were observed in the beta-transitions of the naphthyl chromophore at 222 and 235 nm, but no Cotton effect was observed in the stiff-stilbene chromophore at 365 nm. The structures of (R)-10 and trans-(R,R)-1 were confirmed by X-ray structural analysis. The optimized structure of cis-1 by MO calculations has a wide chiral cavity of 7-8 A in diameter, whereas trans-1 cannot form an intramolecular cavity based on the X-ray data. Irradiation of (R,R)-trans-1 with black light (lambda = 365 nm) in CH3CN or benzene at 23 degrees C led to the conversion to the corresponding cis-isomer, as was monitored by 1H NMR, UV-vis, and CD spectra. At the photostationary state, the cis-1/trans-1 ratio was 86/14 in benzene or 75/25 in CH3CN. On the other hand, irradiation of the cis-1/trans-1 (75/25) mixture in CH3CN with an ultra-high-pressure Hg lamp at 23 degrees C (lambda = 410 nm) led to the photostationary state, where the cis-1/trans-1 ratio was estimated to be 9/91 on the basis of the 1H NMR spectra. The cis-trans and trans-cis interconversions could be repeated 10 times without decomposition of the C=C double bond. Thus, a new type of photoswitchable molecule has been developed, and trans-1 and cis-1 were quite durable under irradiation conditions. The guest binding properties of the BINOL moieties of trans- and cis-(R,R)-1 with F-, Cl-, and H2PO4- were examined by 1H NMR titration in CDCl3. Similar interaction with F- and Cl- was observed in trans-1 (host/guest = 1/1, Kassoc = (1.0 +/- 0.13) x 103 for F- and (4.6 +/- 0.72) x 102 M-1 for Cl-) and cis-1 (host/guest = 1/1, Kassoc = (1.0 +/- 0.13) x 103 for F- and (5.9 +/- 0.69) x 10 M-1 for Cl-), but H2PO4- interacted differently: the cis-isomer formed the 1/1 complex (Kassoc = (9.38 +/- 2.67) x 10 M-1), whereas multistep equilibrium was expected for the trans-isomer.

Theoretical study on the gas adsorption capacity and selectivity of CPM-200-In/Mg and CPM-200-In/Mg-X (-X = -NH2, -OH, -N, -F).

PubMed

Liu, Xiao-le; Chen, Guang-Hui; Wang, Xiu-Jun; Li, Peng; Song, Yi-Bing; Li, Rui-Yan

2017-11-15

The adsorption capacities of a heterometallic metal-organic framework (CPM-200-In/Mg) to VOCs (HCHO, C 2 H 4 , CH 4 , C 2 H 2 , C 3 H 8 , C 2 H 6 , C 2 H 3 Cl, C 2 H 2 Cl 2 , CH 2 Cl 2 and CHCl 3 ) and some inorganic gas molecules (HCN, SO 2 , NO, CO 2 , CO, H 2 S and NH 3 ), as well as its selectivity in ternary mixture systems of natural gas and post-combustion flue gas are theoretically explored at the grand canonical Monte Carlo (GCMC) and density functional theory (DFT) levels. It is shown that CPM-200-In/Mg is suitable for the adsorption of VOCs, particularly for HCHO (up to 0.39 g g -1 at 298 K and 1 bar), and the adsorption capacities of some inorganic gas molecules such as SO 2 , H 2 S and CO 2 match well with the sequence of their polarizability (SO 2 > H 2 S > CO 2 ). The large adsorption capacities of HCN and HCHO in the framework result from the strong interaction between adsorbates and metal centers, based on analyzing the radial distribution functions (RDF). Comparing C 2 H 4 and CH 4 molecules interacting with CPM-200-In/Mg by VDW interaction, we speculate that the high adsorption capacities of their chlorine derivatives in the framework could be due to the existence of halogen bonding or strong electrostatic and VDW interactions. It is found that the basic groups, including -NH 2 , -N and -OH, can effectively improve both the adsorption capacities and selectivity of CPM-200-In/Mg for harmful gases. Note that the adsorption capacity of CPM-200-In/Mg-NH 2 (site 2) (245 cm 3 g -1 ) for CO 2 exceeded that of MOF-74-Mg (228 cm 3 g -1 ) at 273 K and 1 bar and that for HCHO can reach 0.41 g g -1 , which is almost twice that of 438-MOF and nearly 45 times of that in active carbon. Moreover, for natural gas mixtures, the decarburization and desulfurization abilities of CPM-200-In/Mg-NH 2 (site 2) have exceeded those of the MOF-74 series, while for post-combustion flue gas mixtures, the desulfurization ability of CPM-200-In/Mg-NH 2 (site 2) is still comparable to those of the MOF-74 series at 303 K and 4 MPa. We hope that the current theoretical study could guide experimental research in the future.

Controlled synthesis of racemic indenyl rare-earth metal complexes via the cooperation between the intramolecular coordination of donor atoms and a bridge.

PubMed

Zhou, Shuangliu; Wu, Zhangshuan; Zhou, Lingmin; Wang, Shaowu; Zhang, Lijun; Zhu, Xiancui; Wei, Yun; Zhai, Jinhua; Wu, Jie

2013-06-03

The reactions of Me2Si(C9H6CH2CH2-DG)2 (DG = NMe2 (1), CH2NMe2 (2), OMe (3), and N(CH2CH2)2O (4)) with [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 in toluene afforded a series of racemic divalent rare-earth metal complexes: {η(5):η(1):η(5):η(1)-Me2Si(C9H5CH2CH2-DG)2}RE (DG = NMe2, RE = Yb (6) and Eu (7); DG = CH2NMe2, RE = Yb (8), Eu (9), and Sm (10); DG = OMe, RE = Yb (11) and Eu (12); DG = N(CH2CH2)2O, RE = Yb (13) and Eu (14)). Similarly, the racemic divalent rare-earth metal complexes {η(5):η(1):η(5):η(1)-Me2Si(C9H5CH2CH2CH2NMe2)(C9H5CH2CH2OMe)}RE (RE = Yb (15) and Eu (16)) were also obtained. The reaction of Me2Si(C9H5CH2CH2OMe)2Li2 with NdCl3 gave a racemic dimeric neodymium chloride {η(5):η(1):η(5)-Me2Si(C9H5CH2CH2OMe)2NdCl}2 (17), whereas the reaction of Me2Si(C9H5CH2CH2NMe2)2Li2 with SmCl3 afforded a racemic dinuclear samarium chloride bridged by lithium chloride {η(5):η(1):η(5):η(1)-Me2Si(C9H5CH2CH2NMe2)2SmCl}2(μ-LiCl) (18). Further reaction of complex 18 with LiCH2SiMe3 provided an unexpected rare-earth metal alkyl complex {η(5):η(1):η(5):η(1):σ-Me2Si(C9H5CH2CH2NMe2)[(C9H5CH2CH2N(CH2)Me]}Sm (19) through the activation of an sp(3) C-H bond α-adjacent to the nitrogen atom. Complexes 19 and {η(5):η(1):η(5):η(1):σ-Me2Si(C9H5CH2CH2NMe2)[(C9H5CH2CH2N(CH2)Me]}Y (20) were also obtained by one-pot reactions of Me2Si(C9H5CH2CH2NMe2)2Li2 with RECl3 followed by treatment with LiCH2SiMe3. All compounds were fully characterized by spectroscopic methods and elemental analysis. Complexes 6-10 and 14-20 were further characterized by single-crystal X-ray diffraction analysis. All of the prepared rare-earth metal complexes were racemic, suggesting that racemic organo rare-earth metal complexes could be controllably synthesized by the cooperation between a bridge and the intramolecular coordination of donor atoms.

Mercury(II) complexes of unsymmetric phosphorus ylides: Synthesis, spectroscopic and antibacterial activity studies

NASA Astrophysics Data System (ADS)

Sabounchei, Seyyed Javad; Panahimehr, Mohammad; Hosseinzadeh, Marjan; Karamian, Roya; Asadbegy, Mostafa; Masumi, Azadeh

2014-03-01

The reaction of Ph2PCH2PPh2 (dppm) with 2-bromo-3-nitroacetophenone and 2,2‧,4‧-trichloroacetophenone in chloroform produce the new phosphonium salts [Ph2PCH2PPh2CH2C(O)C6H4NO2]Br (1) and [Ph2PCH2PPh2CH2C(O)C6H3Cl2]Cl (2). Further, by reaction of the monophosphonium salts of dppm with the strong base triethylaminethe corresponding bidentate phosphorus ylides, Ph2PCH2PPh2C(H)C(O)C6H4NO2 (3) and Ph2PCH2PPh2C(H)C(O)C6H3Cl2 (4) were obtained. The reaction of these ligands with mercury(II) halides in dry methanol led to the formation of the mononuclear complexes {HgX2[(Ph2PCH2PPh2C(H)C(O)C6H4NO2)]} [X = Cl (5), Br (6), I (7)] and {HgX2[(Ph2PCH2PPh2C(H)C(O)C6H3Cl2)]} [X = Cl (8), Br (9), I (10)]. Characterization of the obtained compounds was performed by elemental analysis, IR, 1H, 31P and 13C NMR. The structure of compound 1 being unequivocally determined by single crystal X-ray diffraction techniques. The mass spectrum of compound 6 (as an instance) also demonstrates the synthesize of these compounds. In all complexes the title ylides are coordinated through the ylidic carbon and the phosphine atom. These compounds form five membered ring under complexation. The antibacterial effects of DMSO solutions of the ligands and their metal complexes were evaluated by the disc diffusion method against six Gram positive and negative bacteria. All compounds represent antibacterial activity against these bacteria with high levels of inhibitory potency exhibited against the Gram positive species.

Formation of dioxins from incineration of foods found in domestic garbage.

PubMed

Katami, Takeo; Yasuhara, Akio; Shibamoto, Takayuki

2004-02-15

There has been great concern about the large amounts of garbage produced by domestic households in the modern world. One of the major sources of dioxins (PCDDs, PCDFs, and coplanar PCBs) in the environment is the combustion of domestic waste materials. Exhaust gases from an incinerator, in which mixtures of 67 food items--including fruits, vegetables, pasta, seafoods, meats, and processed foods and seasoned foods--were analyzed for dioxins. Gases collected at the chimney port (9.15 ng/g) contained less total dioxins than those collected at the chamber port (29.1 ng/g). The levels of Cl1-Cl6-PCDDs and Cl1-Cl5-PCDFs were much lower in the gas collected at the chimney port than in the gas collected at the chamber port. The levels of Cl7-Cl8-PCDDs and Cl6-Cl8-PCDFs were higher in the gas collected at the chimney port than in the gas collected at the chamber port. A total of Cl4-Cl8-PCDDs (1.84-3.04 ng/g) comprised over 80% of the total PCDDs formed (2.24-4.00 ng/g). Total PCDFs (16.2-22.6 ng/g) comprised 78-86% of the total dioxins formed (18.9-29.1 ng/g). The PCDFs formed in the greatest amounts were M1CDFs (9.68-10.7 ng/g). Mixtures of commonly consumed food items produced ppb levels of total dioxins in exhaust gases upon combustion, suggesting that incineration of domestic food wastes is one of the sources of dioxins in the environment. A mixture containing some seasoned foods, such as mayonnaise spread on bread, produced more dioxins (29.1 ng/g) than a mixture without seasoned foods did (18.9 ng/g).

Isotope fractionation associated with the direct photolysis of 4-chloroaniline.

PubMed

Ratti, Marco; Canonica, Silvio; McNeill, Kristopher; Erickson, Paul R; Bolotin, Jakov; Hofstetter, Thomas B

2015-04-07

Compound-specific isotope analysis is a useful approach to track transformations of many organic soil and water pollutants. Applications of CSIA to characterize photochemical processes, however, have hardly been explored. In this work, we systematically studied C and N isotope fractionation associated with the direct photolysis of 4-Cl-aniline used as a model compound for organic micropollutants that are known to degrade via photochemical processes. Laboratory experiments were carried out at an irradiation wavelength of 254 nm over the pH range 2.0 to 9.0 as well as in the presence of Cs(+) as a quencher of excited singlet 4-Cl-aniline at pH 7.0 and 9.0. We observed considerable variation of C and N isotope enrichment factors, ϵC and ϵN, between -1.2 ± 0.2‰ to -2.7 ± 0.2‰ for C and -0.6 ± 0.2‰ to -9.1 ± 1.6‰ for N, respectively, which could not be explained by the speciation of 4-Cl-aniline alone. In the presence of 1 M Cs(+), we found a marked increase of apparent (13)C-kinetic isotope effects ((13)C-AKIE) and decrease of 4-Cl-aniline fluorescence lifetimes. Our data suggest that variations of C and N isotope fractionation originate from heterolytic dechlorination of excited triplet and singlet states of 4-Cl-aniline. Linear correlations of (13)C-AKIE vs (15)N-AKIE were distinctly different for these two reaction pathways and may be explored further for the identification of photolytic aromatic dechlorination reactions.

Weak hydrogen bonding and fluorous interactions in the chloride and bromide salts of 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium.

PubMed

Lu, Norman; Wei, Rong Jyun; Lin, Kwan Yu; Alagesan, Mani; Wen, Yuh Sheng; Liu, Ling Kang

2017-04-01

Neutralization of 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridine with hydrohalo acids HX (X = Cl and Br) yielded the pyridinium salts 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium chloride, C 9 H 10 F 4 NO + ·Cl - , (1), and 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium bromide, C 9 H 10 F 4 NO + ·Br - , (2), both carrying a fluorous side chain at the para position of the pyridinium ring. Single-crystal X-ray diffraction techniques revealed that (1) and (2) are isomorphous. The halide anions accept four hydrogen bonds from N-H, ortho-C-H and CF 2 -H groups. Two cations and two anions form a centrosymmetric dimeric building block, utilizing complimentary N-H...X...H-Csp 3 connections. These dimers are further crosslinked, utilizing another complimentary Csp 2 -H...X...H-Csp 2 connection. The pyridinium rings are π-stacked, forming columns running parallel to the a axis that make angles of ca 44-45° with the normal to the pyridinium plane. There are also supramolecular C-H...F-C interactions, namely bifurcated C-H...F and bifurcated C-F...H interactions; additionally, one type II C-F...F-C halogen bond has been observed.

Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos.

PubMed

Liu, Lihua; Li, Yifan; Coelhan, Mehmet; Chan, Hing Man; Ma, Wanli; Liu, Liyan

2016-12-01

Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C 10- groups (C 10 H 18 Cl 4 , 1,2,5,6,9,10-C 10 H 16 Cl 6 and C 10 H 15 Cl 7 ) were more toxic than the C 12- groups (C 12 H 22 Cl 4 , C 12 H 19 Cl 7 and 1,1,1,3,10,12,12,12-C 12 H 18 Cl 8 ) and Cereclor 63L. The C 10- groups were also more potent than C 12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C 10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C 10 H 18 Cl 4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C 10 H 18 Cl 4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

(2SR,3RS)-Benz­yl[4-chloro-1-(4-chloro­phen­yl)-1-methoxy­carbon­yl-2-but­yl]­ammonium chloride

PubMed Central

Kaupang, Åsmund; Bolsønes, Marianne; Gamadeku, Thywill; Hansen, Tore; Hennum, Martin Johanson; Görbitz, Carl Henrik

2008-01-01

In the racemic hydro­chloride salt of the title ester, C19H22Cl2NO2 +·Cl−, the penta­noic acid chain shows a mixture of trans and gauche orientations to give an overall helical conformation. The dihedral angle between the two aromatic rings is 26.11 (10)°. The charged secondary amine function participates in two N—H⋯Cl hydrogen bonds. PMID:21201230

Mechanochemistry of the LiBH 4–AlCl 3 System: Structural Characterization of the Products by Solid-State NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, T.; Dolotko, O.; Gupta, S.

The double-cation metal borohydride, Li 4Al 3(BH 4) 13, mechanochemically produced from a 13:3 mixture of lithium borohydride (LiBH 4) and aluminum chloride (AlCl 3), has a low hydrogen desorption temperature; however, the material’s decomposition is accompanied by a large emission of toxic diborane (B 2H 6). In this study, we found that a decrease of the LiBH 4:AlCl 3 ratio in the starting mixture yields increased amounts of partially chlorinated products that also dehydrogenate at low temperature, but release negligibly small amounts of diborane. Extensive characterization by solid-state NMR spectroscopy (SSNMR) and powder X-ray diffraction (XRD) found that themore » 11:3 ratio product maintains the Li 4Al 3(BH 4) 13-like structure, with additional Cl – anions substituting for [BH 4] – compared to the 13:3 mixture. Further decrease of relative LiBH 4 concentration in the starting mixture to 9:3 results in a different product composed of tetrahedral [Al(BH 4) 4] - and [Al(BH 4) 2Cl 2] - complexes, in which two hydrogen atoms of each borohydride group are bridged to aluminum sites. Additionally, SSNMR revealed the covalent character of the Al–H bonds, which is not observed in Li 4Al 3(BH 4) 13. In conclusion, these findings suggest that the Al–Cl bonding present in the chlorinated complexes prevents the formation of Al(BH 4) 3, which is a known intermediate leading to the formation of diborane during thermal dehydrogenation of the nearly chlorine-free Li 4Al 3(BH 4) 13.« less

Mechanochemistry of the LiBH 4–AlCl 3 System: Structural Characterization of the Products by Solid-State NMR

DOE PAGES

Kobayashi, T.; Dolotko, O.; Gupta, S.; ...

2017-12-19

The double-cation metal borohydride, Li 4Al 3(BH 4) 13, mechanochemically produced from a 13:3 mixture of lithium borohydride (LiBH 4) and aluminum chloride (AlCl 3), has a low hydrogen desorption temperature; however, the material’s decomposition is accompanied by a large emission of toxic diborane (B 2H 6). In this study, we found that a decrease of the LiBH 4:AlCl 3 ratio in the starting mixture yields increased amounts of partially chlorinated products that also dehydrogenate at low temperature, but release negligibly small amounts of diborane. Extensive characterization by solid-state NMR spectroscopy (SSNMR) and powder X-ray diffraction (XRD) found that themore » 11:3 ratio product maintains the Li 4Al 3(BH 4) 13-like structure, with additional Cl – anions substituting for [BH 4] – compared to the 13:3 mixture. Further decrease of relative LiBH 4 concentration in the starting mixture to 9:3 results in a different product composed of tetrahedral [Al(BH 4) 4] - and [Al(BH 4) 2Cl 2] - complexes, in which two hydrogen atoms of each borohydride group are bridged to aluminum sites. Additionally, SSNMR revealed the covalent character of the Al–H bonds, which is not observed in Li 4Al 3(BH 4) 13. In conclusion, these findings suggest that the Al–Cl bonding present in the chlorinated complexes prevents the formation of Al(BH 4) 3, which is a known intermediate leading to the formation of diborane during thermal dehydrogenation of the nearly chlorine-free Li 4Al 3(BH 4) 13.« less

Dialkylimidazolium Chlorides

DTIC Science & Technology

1981-01-01

Force Systems Command U. S. Air Force Academy, Colorado 80840 I7 *i iL•- r.•r -i- ABSTRACT A- A - i The synthesis of a homologous series of 1 -methyl...Chemical Co. and was vacuum distilled from BaO before use. The 1 - chloropropane and 1 -chlorobutane were obtained from the Aldrich Chemical Co. and were used...23.52% Cl, 1.84% 0. l-Methvl-3-propylimidazolium chloride. 1 -Methylimidazole (10.1 g, 0.123 mol) and l- chloropropane (12.7 g, 0.161 mol) were mixed in

Strong intramolecular Si-N interactions in the chlorosilanes Cl3-nHnSiOCH2CH2NMe2 (n = 1-3).

PubMed

Hagemann, Michael; Mix, Andreas; Berger, Raphael J F; Pape, Tania; Mitzel, Norbert W

2008-11-17

The compounds Cl 3SiOCH 2CH 2NMe 2 ( 1) and Cl 2HSiOCH 2CH 2NMe 2 ( 2) were prepared by reactions of lithium 2-(dimethylamino)ethanolate with SiCl 4 and HSiCl 3. The analogous reaction with H 2SiCl 2 gave ClH 2SiOCH 2CH 2NMe 2 ( 3), but only in a mixture with Cl 2HSiOCH 2CH 2NMe 2 ( 2), from which it could not be separated. All compounds were characterized by IR and NMR ( (1)H, (13)C, (29)Si) spectroscopy, 1 and 2 by elemental analyses and by determination of their crystal structures. Cl 3SiOCH 2CH 2NMe 2 ( 1) and Cl 2HSiOCH 2CH 2NMe 2 ( 2) crystallize as monomeric ring compounds with pentacoordinate silicon atoms participating in intramolecular Si-N bonds [2.060(2) A ( 1), 2.037(2) A ( 2)]. The dative bonds in 1 and 2 between the silicon and nitrogen atoms could also be proven to exist at low temperatures in solution in (1)H, (29)Si-HMBC-NMR experiments by detection of the scalar coupling between the (29)Si and the protons of the NCH 2 and NCH 3 groups. A function describing the chemical shift delta exp (29)Si dependent on the chemical shifts of the individual equilibrium components, the temperature, and the free enthalpy of reaction was worked out and fitted to the experimental VT-NMR data of 1 and 2. This provided values of the free reaction enthalpies of Delta G = -28.8 +/- 3.9 kJ x mol (-1) for 1 and Delta G = -22.3 +/- 0.4 kJ x mol (-1) for 2 and estimates for the chemical shifts of open-chain (index o) and ring conformers (index r) for 1 of delta r = -94 +/- 2 ppm and delta o = -36 +/- 5 ppm and for 2 of delta r = -82 +/- 1 ppm and delta o = -33 +/- 4 ppm. The value of delta r for 1 is very close to that obtained from a solid-state (29)Si MAS NMR spectrum. Quantumchemical calculations (up to MP2/TZVPP) gave largely differing geometries for 1 (with a Si...N distance of 3.072 A), but well reproduced the geometry of 2. These differences are due to Cl...H and Cl...C repulsions and solid state effects, which can be modeled by conductor-like screening model calculations and also rationalized in terms of the topology of the electron density, which was analyzed in terms of the quantum theory of atoms in molecules.

TeX4 (X = F, Cl, Br) as Lewis acids--complexes with soft thio- and seleno-ether ligands.

PubMed

Hector, Andrew L; Jolleys, Andrew; Levason, William; Reid, Gillian

2012-08-28

TeF(4) reacts with OPR(3) (R = Me or Ph) in anhydrous CH(2)Cl(2) to give the colourless, square based pyramidal 1 : 1 complexes [TeF(4)(OPR(3))] only, in which the OPR(3) is coordinated basally in the solid state, (R = Me: d(Te-O) = 2.122(2) Å; R = Ph: d(Te-O) = 2.1849(14) Å). Variable temperature (19)F{(1)H}, (31)P{(1)H} and (125)Te{(1)H} NMR spectroscopic studies strongly suggest this is the low temperature structure in solution, although the systems are dynamic. The much softer donor ligands SMe(2) and SeMe(2) show a lower affinity for TeF(4), although unstable, yellow products with spectroscopic features consistent with [TeF(4)(EMe(2))] are obtained by the reaction of TeF(4) in neat SMe(2) or via reaction in CH(2)Cl(2) with SeMe(2). TeX(4) (X = F, Cl or Br) causes oxidation and halogenation of TeMe(2) to form X(2)TeMe(2). The Br(2)TeMe(2) hydrolyses in trace moisture to form [BrMe(2)Te-O-TeMe(2)Br], the crystal structure of which has been determined. TeX(4) (X = Cl or Br) react with the selenoethers SeMe(2), MeSe(CH(2))(3)SeMe or o-C(6)H(4)(SeMe)(2) (X = Cl) in anhydrous CH(2)Cl(2) to give the distorted octahedral monomers trans-[TeX(4)(SeMe(2))(2)], cis-[TeX(4){MeSe(CH(2))(3)SeMe}] and cis-[TeCl(4){o-C(6)H(4)(SeMe)(2)}], which have been characterised by IR, Raman and multinuclear NMR ((1)H, (77)Se{(1)H} and (125)Te{(1)H}) spectroscopy, and via X-ray structure determinations of representative examples. Tetrahydrothiophene (tht) can form both 1 : 1 and 1 : 2 Te : L complexes. For X = Br, the former has been shown to be a Br-bridged dimer, [Br(3)(tht)Te(μ-Br)(2)TeBr(3)(tht)], by crystallography with the tht ligands anti, whereas the latter are trans-octahedral monomers. Like its selenoether analogue, MeS(CH(2))(3)SMe forms distorted octahedral cis-chelates, [TeX(4){MeS(CH(2))(3)SMe}], whereas the more rigid o-C(6)H(4)(SMe)(2) unexpectedly forms a zig-zag chain polymer in the solid state, [TeCl(4){o-C(6)H(4)(SMe)(2)}](n), in which the dithioether adopts an extremely unusual bridging mode. This is in contrast to the chelating monomer, cis-[TeCl(4){o-C(6)H(4)(SeMe)(2)}], formed with the analogous selenoether and may be attributed to small differences in the ligand chelate bite angles. The wider bite angle xylyl-linked bidentates, o-C(6)H(4)(CH(2)EMe(2))(2) behave differently; the thioether forms cis-chelated [TeX(4){o-C(6)H(4)(CH(2)SMe)(2)}] confirmed crystallographically, whereas the selenoether undergoes C-Se cleavage and rearrangement on treatment with TeX(4), forming the cyclic selenonium salts, [C(9)H(11)Se](2)[TeX(6)]. The tetrathiamacrocycle, [14]aneS(4) (1,4,8,11-tetrathiacyclotetradecane), does not react cleanly with TeCl(4), but forms the very poorly soluble [TeCl(4)([14]aneS(4))](n), shown by crystallography to be a zig-zag polymer with exo-coordinated [14]aneS(4) units linked via alternate S atoms to a cis-TeCl(4) unit. Trends in the (125)Te{(1)H} NMR shifts for this series of Te(IV) halides chalcogenoether complexes are discussed.

Copper-promoted methylene C-H oxidation to a ketone derivative by O2.

PubMed

Deville, Claire; McKee, Vickie; McKenzie, Christine J

2017-01-17

The methylene group of the ligand 1,2-di(pyridin-2-yl)-ethanone oxime (dpeo) is slowly oxygenated by the O 2 in air under ambient conditions when [Cu(dpeo) 2 ](ClO 4 ) 2 is dissolved in ethanol or acetonitrile. An initial transient ketone product, 2-(hydroxyimino)-1,2-di(pyridine-2-yl)ethanone, (hidpe) was characterized in the heteroleptic copper(ii) complex [Cu(bpca)(hidpe)](ClO 4 ). The co-ligand in this complex, N-(2'-pyridylcarbonyl)pyridine-2-carboximidate (bpca - ), is derived from a copper-promoted Beckmann rearrangement of hidpe. In the presence of bromide only [Cu(bpca)Br] is isolated. When significant water is present in reaction mixtures copper complexes of dpeo, hidpe and bpca - are not recovered and [Cu(pic) 2 H 2 O] is isolated. This occurs since two equivalents of picolinate are ultimately generated from one equivalent of oxidized and hydrolysed dpeo. The copper-dependent O 2 activation and consequent stoichiometric dpeo C-H oxidation is reminiscent of the previously observed catalysis of dpeo oxidation by Mn(ii) [C. Deville, S. K. Padamati, J. Sundberg, V. McKee, W. R. Browne, C. J. McKenzie, Angew. Chem., Int. Ed., 2016, 55, 545-549]. By contrast dpeo oxidation is not observed during complexation reactions with other late transition metal(ii) ions (M = Fe, Co, Ni, Zn) under aerobic conditions. In these cases bis and tris complexes of bidentate dpeo are isolated in good yields. It is interesting to note that dpeo is not oxidised by H 2 O 2 in the absence of Cu or Mn, suggesting that metal-based oxidants capable of C-H activation are produced from the dpeo-Cu/Mn systems and specifically O 2 . The metastable copper complexes [Cu(dpeo) 2 ](ClO 4 ) 2 and [Cu(bpca)(hidpe)](ClO 4 ), along with [NiX 2 (dpeo) 2 ] (X = Cl, Br), [Ni(dpeo) 3 ](ClO 4 ) 2 , [Co(dpeo) 3 ](ClO 4 ) 3 and the mixed valence complex [Fe III Fe(dpeo-H) 3 (dpeo) 3 ](PF 6 ) 4 , have been structurally characterized.

Formation of a 1,4-diamino-2,3-disila-1,3-butadiene derivative.

PubMed

Mondal, Kartik Chandra; Roesky, Herbert W; Dittrich, Birger; Holzmann, Nicole; Hermann, Markus; Frenking, Gernot; Meents, Alke

2013-10-30

A 1,4-diamino-2,3-disila-1,3-butadiene derivative of composition (Me2-cAAC)2(Si2Cl2) (Me2-cAAC = :C(CMe2)2(CH2)N-2,6-iPr2C6H3) was synthesized by reduction of the Me2-cAAC:SiCl4 adduct with KC8. This compound is stable at 0 °C for 3 months in an inert atmosphere. Theoretical studies reveal that the silicon atoms exhibit pyramidal coordination, where the Cl-Si-Si-Cl dihedral angle is twisted by 43.3° (calcd 45.9°). The two silicon-carbon bonds are intermediates between single and double Si-C bonds due to twisting of the C-Si-Si-C dihedral angle (163.6°).

Carbon K-edge X-ray absorption spectroscopy and time-dependent density functional theory examination of metal-carbon bonding in metallocene dichlorides.

PubMed

Minasian, Stefan G; Keith, Jason M; Batista, Enrique R; Boland, Kevin S; Kozimor, Stosh A; Martin, Richard L; Shuh, David K; Tyliszczak, Tolek; Vernon, Louis J

2013-10-02

Metal-carbon covalence in (C5H5)2MCl2 (M = Ti, Zr, Hf) has been evaluated using carbon K-edge X-ray absorption spectroscopy (XAS) as well as ground-state and time-dependent hybrid density functional theory (DFT and TDDFT). Differences in orbital mixing were determined experimentally using transmission XAS of thin crystalline material with a scanning transmission X-ray microscope (STXM). Moving down the periodic table (Ti to Hf) has a marked effect on the experimental transition intensities associated with the low-lying antibonding 1a1* and 1b2* orbitals. The peak intensities, which are directly related to the M-(C5H5) orbital mixing coefficients, increase from 0.08(1) and 0.26(3) for (C5H5)2TiCl2 to 0.31(3) and 0.75(8) for (C5H5)2ZrCl2, and finally to 0.54(5) and 0.83(8) for (C5H5)2HfCl2. The experimental trend toward increased peak intensity for transitions associated with 1a1* and 1b2* orbitals agrees with the calculated TDDFT oscillator strengths [0.10 and 0.21, (C5H5)2TiCl2; 0.21 and 0.73, (C5H5)2ZrCl2; 0.35 and 0.69, (C5H5)2HfCl2] and with the amount of C 2p character obtained from the Mulliken populations for the antibonding 1a1* and 1b2* orbitals [8.2 and 23.4%, (C5H5)2TiCl2; 15.3 and 39.7%, (C5H5)2ZrCl2; 20.1 and 50.9%, (C5H5)2HfCl2]. The excellent agreement between experiment, theory, and recent Cl K-edge XAS and DFT measurements shows that C 2p orbital mixing is enhanced for the diffuse Hf (5d) and Zr (4d) atomic orbitals in relation to the more localized Ti (3d) orbitals. These results provide insight into how changes in M-Cl orbital mixing within the metallocene wedge are correlated with periodic trends in covalent bonding between the metal and the cyclopentadienide ancillary ligands.

Detecting Illicit Trafficking

DTIC Science & Technology

2001-09-01

n , p ’b 9 MeV and up activ.,7.13 s C0 ’Cl( n ,I : Ca thermal prompt Ci 35Cl ( n , n 𔃾 C:)3Ci 3 MeV and up prompt CI 7Ci( n , p )yS 14 MeV activ.,4.9 min 377 ...Octogene 3.95 ppt/ 3x 10- 9 9,1 376 Table 2. Elementary composition of some CW agents (atom number/molecule). Agent Cl P As S F 0 N C H S-Mustard (HD) 2 1...types of sources are used: 252Cf that decays by spontaneous fission and Be(a, n ) sources, where as an a emitter americium, or plutonium,

THERMODYNAMICS OF THE CHLORINE-HYDROGEN-SILICON SYSTEM.

DTIC Science & Technology

The equilibrium composition of the gas phase and the weight of silicon deposited were calculated for SiCl4 /H2 and SiHCl3/H2 mixtures at temperatures... SiCl4 /H2 and SiHCl3/H2 mixtures may be explained in terms of thermodynamics alone. (Author)

Redox non-innocence of thioether crowns: spectroelectrochemistry and electronic structure of formal nickel(III) complexes of aza-thioether macrocycles.

PubMed

Stephen, Emma; Huang, Deguang; Shaw, Jennifer L; Blake, Alexander J; Collison, David; Davies, E Stephen; Edge, Ruth; Howard, Judith A K; McInnes, Eric J L; Wilson, Claire; Wolowska, Joanna; McMaster, Jonathan; Schröder, Martin

2011-09-05

The Ni(II) complexes [Ni([9]aneNS(2)-CH(3))(2)](2+) ([9]aneNS(2)-CH(3)=N-methyl-1-aza-4,7-dithiacyclononane), [Ni(bis[9]aneNS(2)-C(2)H(4))](2+) (bis[9]aneNS(2)-C(2)H(4)=1,2-bis-(1-aza-4,7-dithiacyclononylethane) and [Ni([9]aneS(3))(2)](2+) ([9]aneS(3)=1,4,7-trithiacyclononane) have been prepared and can be electrochemically and chemically oxidized to give the formal Ni(III) products, which have been characterized by X-ray crystallography, UV/Vis and multi-frequency EPR spectroscopy. The single-crystal X-ray structure of [Ni(III)([9]aneNS(2)-CH(3))(2)](ClO(4))(6)·(H(5)O(2))(3) reveals an octahedral co-ordination at the Ni centre, while the crystal structure of [Ni(III)(bis[9]aneNS(2)-C(2)H(4))](ClO(4))(6)·(H(3)O)(3)·3H(2)O exhibits a more distorted co-ordination. In the homoleptic analogue, [Ni(III)([9]aneS(3))(2)](ClO(4))(3), structurally characterized at 30 K, the Ni-S distances [2.249(6), 2.251(5) and 2.437(2) Å] are consistent with a Jahn-Teller distorted octahedral stereochemistry. [Ni([9]aneNS(2)-CH(3))(2)](PF(6))(2) shows a one-electron oxidation process in MeCN (0.2 M NBu(4)PF(6), 293 K) at E(½)=+1.10 V versus Fc(+)/Fc assigned to a formal Ni(III)/Ni(II) couple. [Ni(bis[9]aneNS(2)-C(2)H(4))](PF(6))(2) exhibits a one-electron oxidation process at E(½)=+0.98 V and a reduction process at E(½)=-1.25 V assigned to Ni(II)/Ni(III) and Ni(II)/Ni(I) couples, respectively. The multi-frequency X-, L-, S-, K-band EPR spectra of the 3+ cations and their 86.2% (61)Ni-enriched analogues were simulated. Treatment of the spin Hamiltonian parameters by perturbation theory reveals that the SOMO has 50.6%, 42.8% and 37.2% Ni character in [Ni([9]aneNS(2)-CH(3))(2)](3+), [Ni(bis[9]aneNS(2)-C(2)H(4))](3+) and [Ni([9]aneS(3))(2)](3+), respectively, consistent with DFT calculations, and reflecting delocalisation of charge onto the S-thioether centres. EPR spectra for [(61)Ni([9]aneS(3))(2)](3+) are consistent with a dynamic Jahn-Teller distortion in this compound. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lamotriginium crotonate and lamotriginium salicylate ethanol monosolvate: the role of solvent molecules in the packing organization.

PubMed

Freire, Eleonora; Echeverría, Gustavo A; Baggio, Ricardo

2017-07-01

Two lamotriginium salts, namely lamotriginium crotonate [systematic name: 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazin-2-ium but-2-enoate, C 9 H 8 Cl 2 N 5 + ·C 4 H 5 O 2 - , (III)] and lamotriginium salicylate [systematic name: 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazin-2-ium 2-hydroxybenzoate ethanol monosolvate, C 9 H 8 Cl 2 N 5 + ·C 7 H 5 O 3 - ·C 2 H 5 OH, (IV)] present extremely similar centrosymmetric hydrogen-bonded A...L...L...A packing building blocks (L is lamotriginium and A is the anion). The fact that salicylate salt (IV) is (ethanol) solvated, while crotonate salt (III) is not, has a profound effect on the way these elemental units aggregate to generate the final crystal structure. Possible reasons for this behaviour are analyzed and the hypothesis raised checked against similar structures in the literature.

2-Chlorobutane

Integrated Risk Information System (IRIS)

2 - Chlorobutane ; CASRN 78 - 86 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

Experimental study of the solubilities of pyrite in NaCl-bearing aqueous solutions at 250-350°C

NASA Astrophysics Data System (ADS)

Ohmoto, Hiroshi; Hayashi, Ken-Ichiro; Kajisa, Yukari

1994-05-01

A total of sixty-three silica capsule experiments were performed to determine the solubilities of pyrite in NaCl-bearing aqueous solutions (0, 0.1, 0.5, 1, 2, 3, and 4 m) at 250, 300, and 350°C at pressures of vapor/liquid coexistence. The starting materials in the capsules were H2O(1) + FeS2( s) + S ° ( s) ± NaCl ( s). After reaction times up to ~ 60 days, the quenched solutions were analyzed for ΣFe, σH2S, ΣSO42-, and pH; the ΣFe content, ranging 5-1,300 ppm, generally increased with increasing temperature and ΣCl content of solution. The calculated solution compositions at the experimental P-T conditions fall mostly in the following ranges: pH = 2.0 to 3.2, logaH2s = -1.9 to -1.0, logaHSO4- = -3.8 to -2.0, and logaH2( aq) = -7.0 to -5.0. Evaluation of the experimental data suggests that the various redox equilibria between solution and mineral were attained in most of the experimental solutions. The pH, aH2S( aq) , and aH2( aq) of the solutions were controlled by the sulfur hydrolysis reaction (48° + 4 H2O( l) = 3 H2S( aq) + HSO4- + H+) and the sulfide/sulfate reaction ( H2S( aq) + 4 H2O( l) = 4 H2( aq) + H+ + HSO4-). The pyrite solubility is controlled by a general reaction: FeS2( s) + nCl- + 2 H+ + H2( aq) = FeCln2- n + 2 H2S( aq). The equilibrium constants for this reaction, as well as those for association of ferrous chloride complexes ( Fe2+ + nCl- = FeCln2- n), were obtained at 250, 300, and 350°C; they were used also to compute the equilibrium constants for the reactions controlling the solubilities of pyrrhotite, magnetite, and hematite: FeS( s) + 2 H+ + nCl- = FeCln2- n + H2S( aq); Fe3O4( s) + 6 H+ + 3 nCl- + H2( aq) = 3 FeCln2- n + H2O( aq); Fe2O3( s) + 4 H+ + 2 nCl- + H2( aq) = 2 FeCln2- n + 3 H2O( aq). Our experimental data suggest that the dominant Fe-Cl complex is FeCl + in solutions of ΣCl ≤ 0.5 m at 250°C and ΣCl ≤ 0.1 m at 300 and 350°C; FeCl 20 is dominant in solutions of the higher ΣCl contents at each temperature. The association constants for FeCl + and FeCl 2 estimated from this study are in good agreement with those estimated recently by HEINRICH and SEWARD (1990), DING and SEYFRIED (1992), Fein et al. (1992), and Palmer and Hyde (1992). Our solubility constants for pyrite are in good agreement with those obtained by CRERAR et al. (1978) and WOOD et al. (1987) for 3 m ΣCl solution at 350°C, but are 0.5-2 orders of magnitude higher than those obtained by them at lower temperatures and/or at lower ΣCl values. Our data suggest that natural hydrothermal fluids that are in equilibrium with pyrite, the most abundant sulfide mineral in the upper crust, are able to transport sufficient amounts (> 10 -m) of both Fe and H 2S to produce pyrite-rich ore deposits at temperatures above 250°C, and possibly at lower temperatures. The solubility of pyrite (and of other Fe-bearing minerals) is affected very little by a change of temperature, provided the pH, aH2( aq), aH2S( aq), and ΣCl values remain constant.

Experimental (FTIR, Raman, UV-visible and PL) and theoretical (DFT and TDDFT) studies on bis(8-hydroxyquinolinium) tetrachlorocobaltate(II) compound

NASA Astrophysics Data System (ADS)

Chaouachi, Soumaya; Elleuch, Slim; Hamdi, Besma; Zouari, Ridha

2016-12-01

The purpose of this paper is to present the chemical preparation, crystal structure, vibrational study and optical features for new organic-inorganic compound [C9H8NO]2CoCl4 abbreviated [8-HQ]2CoCl4. The structural study by X-ray diffraction prove that this compound crystallize in a monoclinic unit-cell with space group C2/c (point group 2/m = C2h). It is built of tetrahedra [CoCl4]2- anions and (C9H8NO)+ cations in the 1/2 ratio. The crystal structure is stabilized by network three-dimensional of Nsbnd H⋯Cl, Nsbnd H⋯O, Osbnd H⋯Cl, Csbnd H⋯Cl hydrogen bonds, and offset π-π stacking interactions. Also, the Hirshfeld Surface projections and Fingerprint plots were elucidated the relative contribution of the type, nature and explore the H⋯Cl, C⋯H, C⋯C, C⋯N, H⋯O intermolecular contacts in the crystal in a visual manner. Furthermore, vibrational analysis of the structural groups in the compound was carried out by both Fourier transforms infrared (FT-IR) and Raman spectra. The spectral data are complemented by good information at the region characteristic of metal-ligand, which evidences coordination through the compound. The optical properties of the crystal were studied by using optical absorption UV-visible and photoluminescence (PL) spectroscopy studies. Theoretical calculations were performed using density functional theory (DFT) at (DFT/B3LYP/LanL2DZ) level in the aim of aiding in studying structural, vibrational and optical properties of the investigated compound. Good relationship consistency is found between the experimental and theoretical studies. Inspection of the optical properties has lead to confirm the exhibition of a green photoluminescence and the occurrence of charge transfer phenomenon in this material.

Functionalization of metallabenzenes through nucleophilic aromatic substitution of hydrogen.

PubMed

Clark, George R; Ferguson, Lauren A; McIntosh, Amy E; Söhnel, Tilo; Wright, L James

2010-09-29

The cationic metallabenzenes [Ir(C(5)H(4){SMe-1})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (1) and [Os(C(5)H(4){SMe-1})(CO)(2)(PPh(3))(2)][CF(3)SO(3)] (2) undergo regioselective nucleophilic aromatic substitution of hydrogen at the metallabenzene ring position γ to the metal in a two-step process that first involves treatment with appropriate nucleophiles and then oxidation. Thus, reaction between compound 1 and NaBH(4), MeLi, or NaOEt gives the corresponding neutral iridacyclohexa-1,4-diene complexes Ir(C(5)H(3){SMe-1}{H-3}{Nu-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2) (Nu = H (3), Me (4), OEt (5)). Similarly, reaction between 2 and NaBH(4) or MeLi gives the corresponding osmacyclohexa-1,4-diene complexes Os(C(5)H(3){SMe-1}{H-3}{Nu-3})(CO)(2)(PPh(3))(2) (Nu = H (8), Me (9)). The metallacyclohexa-1,4-diene rings in all these compounds are rearomatized on treatment with the oxidizing agent O(2), CuCl(2), or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Accordingly, the cationic metallabenzene 1 or 2 is returned after reaction between 3 and DDQ/NEt(4)PF(6) or between 8 and DDQ/NaO(3)SCF(3), respectively. The substituted cationic iridabenzene [Ir(C(5)H(3){SMe-1}{Me-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (6) or [Ir(C(5)H(4){SMe-1}{OEt-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (7) is produced in a similar manner through reaction between 4 or 5, respectively, and DDQ/NEt(4)PF(6), and the substituted cationic osmabenzene [Os(C(5)H(3){SMe-1}{Me-3})(CO)(2)(PPh(3))(2)]Cl (10) is formed in good yield on treatment of 9 with CuCl(2). The starting cationic iridabenzene 1 is conveniently prepared by treatment of the neutral iridabenzene Ir(C(5)H(4){SMe-1})Cl(2)(PPh(3))(2) with NaS(2)CNEt(2) and NEt(4)PF(6), and the related starting cationic osmabenzene 2 is obtained by treatment of Os(C(5)H(4){S-1})(CO)(PPh(3))(2) with CF(3)SO(3)CH(3) and CO. The stepwise transformations of 1 into 6 or 7 as well as 2 into 10 provide the first examples in metallabenzene chemistry of regioselective nucleophilic aromatic substitutions of hydrogen by external nucleophiles. DFT calculations have been used to rationalize the preferred sites for nucleophilic attack at the metallabenzene rings of 1 and 2. The crystal structures of 1, 3, 6, and 7 have been obtained.

Solvolysis of para-substituted cumyl chlorides. Brown and Okamoto's electrophilic substituent constants revisited using continuum solvent models.

PubMed

DiLabio, Gino A; Ingold, K U

2004-03-05

Brown and Okamoto (J. Am. Chem. Soc. 1958, 80, 4979) derived their electrophilic substitutent constants, sigma(p)+, from the relative rates of solvolysis of ring-substituted cumyl chlorides in an acetone/water solvent mixture. Application of the Hammett equation to the rates for the meta-substituted cumyl chlorides, where there could be no resonance interaction with the developing carbocation, gave a slope, rho(+) = -4.54 ( identical with 6.2 kcal/mol free energy). Rates for the para-substituted chlorides were then used to obtain sigma(p)+ values. We have calculated gas-phase C-Cl heterolytic bond dissociation enthalpy differences, Delta BDE(het) (= BDE(het)(4-YC(6)H(4)CMe(2)Cl) - BDE(het)(C(6)H(5)CMe(2)Cl)), for 16 of the 4-Y substituents employed by Brown and Okamoto. The plot of Delta BDE(het) vs sigma(p)+ gave rho(+) (SD) = 16.3 (2.3) kcal/mol, i.e., a rho(+) value roughly 2.5 times greater than experiment. Inclusion of solvation (water) energies, calculated using three continuum solvent models, reduced rho(+) and SD. The computationally least expensive model used, SM5.42R (Li et al. Theor. Chem. Acc. 1999, 103, 9) gave the best agreement with experiment. This model yielded rho(+) (SD) = 7.7 (0.9) kcal/mol, i.e., a rho(+) value that is only 24% larger than experiment.

Dissolution of nontronite in chloride brines and implications for the aqueous history of Mars

NASA Astrophysics Data System (ADS)

Steiner, M. H.; Hausrath, E. M.; Elwood Madden, M. E.; Tschauner, O.; Ehlmann, B. L.; Olsen, A. A.; Gainey, S. R.; Smith, J. S.

2016-12-01

Increasing evidence suggests the presence of recent liquid water, including brines, on Mars. Brines have therefore likely impacted clay minerals such as the Fe-rich mineral nontronite found in martian ancient terrains. To interpret these interactions, we conducted batch experiments to measure the apparent dissolution rate constant of nontronite at 25.0 °C at activities of water (aH2O) of 1.00 (0.01 M CaCl2 or NaCl), 0.75 (saturated NaCl or 3.00 mol kg-1 CaCl2), and 0.50 (5.00 mol kg-1 CaCl2). Experiments at aH2O = 1.00 (0.01 M CaCl2) were also conducted at 4.0 °C, 25.0 °C, and 45.0 °C to measure an apparent activation energy for the dissolution of nontronite. Apparent dissolution rate constants at 25.0 °C in CaCl2-containing solutions decrease with decreasing activity of water as follows: 1.18 × 10-12 ± 9 × 10-14 mol mineral m-2 s-1 (aH2O = 1.00) > 2.36 × 10-13 ± 3.1 × 10-14 mol mineral m-2 s-1 (aH2O = 0.75) > 2.05 × 10-14 ± 2.9 × 10-15 mol mineral m-2 s-1 (aH2O = 0.50). Similar results were observed at 25.0 °C in NaCl-containing solutions: 1.89 × 10-12 ± 1 × 10-13 mol mineral m-2 s-1 (aH2O = 1.00) > 1.98 × 10-13 ± 2.3 × 10-14 mol mineral m-2 s-1 (aH2O = 0.75). This decrease in apparent dissolution rate constants with decreasing activity of water follows a relationship of the form: log kdiss = 3.70 ± 0.20 × aH2O - 15.49, where kdiss is the apparent dissolution rate constant, and aH2O is the activity of water. The slope of this relationship (3.70 ± 0.20) is within uncertainty of that of other minerals where the relationship between dissolution rates and activity of water has been tested, including forsteritic olivine (log R = 3.27 ± 0.91 × aH2O - 11.00) (Olsen et al., 2015) and jarosite (log R = 3.85 ± 0.43 × aH2O - 12.84) (Dixon et al., 2015), where R is the mineral dissolution rate. This result allows prediction of mineral dissolution as a function of activity of water and suggests that with decreasing activity of water, mineral dissolution will decrease due to the role of water as a ligand in the reaction. Apparent dissolution rate constants in the dilute NaCl solution (1.89 × 10-12 ± 1 × 10-13 mol mineral m-2 s-1) are slightly greater than those in the dilute CaCl2 solutions (1.18 × 10-12 ± 9 × 10-14 mol mineral m-2 s-1). We attribute this effect to the exchange of Na with Ca in the nontronite interlayer. An apparent activation energy of 54.6 ± 1.0 kJ/mol was calculated from apparent dissolution rate constants in dilute CaCl2-containing solutions at temperatures of 4.0 °C, 25.0 °C, and 45.0 °C: 2.33 × 10-13 ± 1.3 × 10-14 mol mineral m-2 s-1 (4.0 °C), 1.18 × 10-12 ± 9 × 10-14 mol mineral m-2 s-1 (25.0 °C), and 4.98 × 10-12 ± 3.8 × 10-13 mol mineral m-2 s-1 (45.0 °C). The greatly decreased dissolution of nontronite in brines and at low temperatures suggests that any martian nontronite found to be perceptibly weathered may have experienced very long periods of water-rock interaction with brines at the low temperatures prevalent on Mars, with important implications for the paleoclimate and long-term potential habitability of Mars.

The coupling of carbon dioxide and epoxides by phenanthroline derivatives containing different Cu(II) complexes as catalyst

NASA Astrophysics Data System (ADS)

Kilic, Ahmet; Palali, Ahmet Arif; Durgun, Mustafa; Tasci, Zeynep; Ulusoy, Mahmut

2013-09-01

A series of the mononuclear Cu(II) metal complexes containing the ligand Bdppz [(9a,13a-dihydro-4,5,9,14-tetraaza-benzo[b]triphenylene-11-yl)-phenyl-methanone] (L1) and Aqphen [(12,17-dihydronaphthol[2,3-h]dipyrido[3,2-a:2‧,3‧-c]-phenazine-12,17-dione)] (L2) were synthesized and used as catalyst for the coupling of carbon dioxide (CO2) and liquid epoxide which served as both reactant and solvent. Dimethylamino pyridine (DMAP) was used as co-catalyst. The yields of epoxides to corresponding cyclic carbonates were determined by comparing the ratio of product to substrate in the 1H NMR spectrum of an aliquot of the reaction mixture. The mononuclear Cu(II) complexes of these ligands were synthesized by treating an ethanol solvent of the appropriate ligand with a different molar amount of CuCl2·2H2O. The Cu(II) complexes were characterized by FT-IR, UV-Vis, elemental analysis, melting point analysis, mass spectra, molar conductivity measurements and magnetic susceptibility techniques. The reaction of the Bdppz and Aqphen ligands in a 1:1, 1:2 or 1:3 mole ratio with CuCl2·2H2O afforded ionic Cu(II) complexes in the presence of Et3N.

STEAM REFORMING OF CHLOROCARBONS: CHLORINATED AROMATICS. (R826694C633)

EPA Science Inventory

Effective dechlorination of chloroaromatics, such as C₆H₅Cl, 1,2-C₆H₄Cl₂, 1,3-C₆H₄Cl₂ and 1,2,4-C₆H₃Cl₃, using catalytic steam reforming has been confirmed ...

Gold(I) Complexes with N-Donor Ligands. 2.(1) Reactions of Ammonium Salts with [Au(acac-kappaC(2))(PR(3))] To Give [Au(NH(3))L](+), [(AuL)(2)(&mgr;(2)-NH(2))](+), [(AuL)(4)(&mgr;(4)-N)](+), or [(AuL)(3)(&mgr;(3)-O)](+). A New and Facile Synthesis of [Au(NH(3))(2)](+) Salts. Crystal Structure of [{AuP(C(6)H(4)OMe-4)(3)}(3)(&mgr;(3)-O)]CF(3)SO(3).

PubMed

Vicente, José; Chicote, María-Teresa; Guerrero, Rita; Jones, Peter G.; Ramírez De Arellano, M. Carmen

1997-09-24

The complexes [Au(acac-kappaC(2))(PR(3))] (acac = acetylacetonate, R = Ph, C(6)H(4)OMe-4) react with (NH(4))ClO(4) to give amminegold(I), [Au(NH(3))(PR(3))]ClO(4), amidogold(I), [(AuPR(3))(2)(&mgr;(2)-NH(2))]ClO(4), or nitridogold(I), [(AuPR(3))(4)(&mgr;(4)-N)]ClO(4), complexes, depending on the reaction conditions. Similarly, [Au(acac-kappaC(2))(PPh(3))] reacts with (NH(3)R')OTf (OTf = CF(3)SO(3)) (1:1) or with [H(3)N(CH(2))(2)NH(2)]OTf (1:1) to give (amine)gold(I) complexes [Au(NH(2)R')(PPh(3))]OTf (R' = Me, C(6)H(4)NO(2)-4) or [(AuPPh(3))(2){&mgr;(2)-H(2)N(CH(2))(2)NH(2)}](OTf)(2), respectively. The ammonium salts (NH(2)R'(2))OTf (R' = Et, Ph) react with [Au(acac-kappaC(2))(PR(3))] (R = Ph, C(6)H(4)OMe-4) (1:2) to give, after hydrolysis, the oxonium salts [(AuPR(3))(3)(&mgr;(3)-O)]OTf (R = Ph, C(6)H(4)OMe-4). When NH(3) is bubbled through a solution of [AuCl(tht)] (tht = tetrahydrothiophene), the complex [Au(NH(3))(2)]Cl precipitates. Addition of [Au(NH(3))(2)]Cl to a solution of AgClO(4) or TlOTf leads to the isolation of [Au(NH(3))(2)]ClO(4) or [Au(NH(3))(2)]OTf, respectively. The crystal structure of [(AuPR(3))(3)(&mgr;(3)-O)]OTf.Me(2)CO (R = C(6)H(4)OMe-4) has been determined: triclinic, space group P&onemacr;, a = 14.884(3) Å, b = 15.828(3) Å, c = 16.061(3) Å, alpha = 83.39(3) degrees, beta = 86.28(3) degrees, gamma = 65.54(3) degrees, R1 (wR2) = 0.0370 (0.0788). The [(AuPR(3))(3)(&mgr;(3)-O)](+) cation shows an essentially trigonal pyramidal array of three gold atoms and one oxygen atom with O-Au-P bond angles of ca. 175 degrees and Au.Au contacts in the range 2.9585(7)-3.0505(14) Å. These cations are linked into centrosymmetric dimers through two short Au.Au [2.9585(7), 3.0919(9) Å] contacts. The gold atoms of the dimer form a six-membered ring with a chair conformation.

The promotion effect of coexisting hygroscopic composition on the reaction between oxalic acid and calcite during humidifying process

NASA Astrophysics Data System (ADS)

Ma, Q.; He, H.

2012-12-01

Internally mixed oxalic acid with mineral dust has been frequently detected in field measurements (Sullivan and Prather, 2007; Wang et al., 2012; Yang et al., 2009). Meanwhile, Furukawa and Takahashi (Furukawa and Takahashi, 2011) found that most of the oxalic acid in mineral mixture is present as metal oxalate complexes in the aerosols, however, the formation mechanism of these complexes is not well known. It was reported that cloud process of H2C2O4/CaCO3 mixture could lead to the formation of calcium oxalate (Gierlus et al., 2012). Recently, we used Raman spectroscopy to investigate the hygroscopic behavior of H2C2O4/CaCO3 mixture below saturation condition as well as the effect of coexisting hygroscopic compositions, e.g. Ca(NO3)2, NaCl, NH4NO3, and (NH4)2SO4. It was found that there was no interaction between H2C2O4 and calcite without third component during humidifying process under ambient condition. In contrast, the presence of coexisting Ca(NO)3, NaCl, or NH4NO3 could promote the reaction between H2C2O4 and calcite by providing an aqueous circumstance after deliquescence, resulting in the formation of calcium oxalate hydrates. Moreover, substitution of strong acid (HNO3) by medium acid (H2C2O4) occurred when water vapor was absorbed in Ca(NO3)2/H2C2O4 mixture (Ma and He, 2012). As for (NH4)2SO4, there existed a competition effect between (NH4)2SO4 and H2C2O4 for the reaction with CaCO3. CaCO3 was preferentially reacted with (NH4)2SO4 to form gypsum in the solution, while the residual NH4+ and C2O42- ions were bonded to (NH4)2C2O4 after efflorescence. These results implies a potential formation pathway of metal oxalate complexes in the atmosphere and also suggests that synergistic effect between different constituents in humidifying process of mixed particles should be considered in future hygroscopic behavior studies.

Reactions of the linear tetranuclear complex Ru sub 4 (CO) sub 10 (CH sub 3 C double bond C(H)C(H) double bond N-i-Pr) sub 2 with oxidizing reagents. Syntheses of halide-bridged (Ru(CO) sub 2 X(CH sub 3 C double bond C(H)C(H) double bond N-i-Pr)) sub 2 and fac-Ru(CO) sub 3 X(CH sub 3 C double bond C(H)C(H) double bond N-i-Pr)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mul, W.P.; Elsevier, C.J.; van Leijen, M.

1991-01-01

The linear tetranuclear complex Ru{sub 4}(CO){sub 10}(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr){sub 2} (1), containing two {eta}{sup 5}-azaruthenacyclopentadienyl systems, reacts with oxidizing reagents (I{sub 2}, Br{sub 2}, NBS, CCl{sub 4}) at elevated temperatures (40-90C) in heptane or benzene to give the new dimeric halide-bridged organoruthenium(II) complexes (Ru(CO){sub 2}X(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr)){sub 2} (X = I (3a), X = Br (3b), Cl (3c); yield 30-80%) together with (Ru(CO){sub 3}X{sub 2}){sub 2}. The reactions of 1 with CX{sub 4} (X = I, Br, Cl) are accelerated by CO, probably because Ru{sub 4}(CO){sub 12}(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr){sub 2} (5), which contains two unbridged metal-metal bonds,more » is formed prior to oxidation. The halide-bridged dimers 3a-c are obtained as mixtures of four isomers, the configurations of which are discussed. Splitting of the halide bridges takes place when a solution of 3a-c is saturated with CO, whereby mononuclear fac-Ru(CO){sub 3}X(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr) (4a-c) is obtained. This process is reversible; ie., passing a stream of nitrogen through a solution of 4a-c or removal of the solvent under vacuum causes the reverse reaction with reformation of 3a-c. Compounds 3a-c and 4a-c have been characterized by IR (3, 4), FD mass (3), {sup 1}H (3, 4), and {sup 13}C{l brace}H{r brace} NMR (4) spectroscopy and satisfactory elemental analyses have been obtained for 3a-c. Compounds 3 and 4 are suitable precursors for the preparation of new homo- and heteronuclear transition-metal complexes.« less

Nano-spatial parameters from 3D to 2D lattice dimensionality by organic variant in [ZnCl4]- [R]+ hybrid materials: Structure, architecture-lattice dimensionality, microscopy, optical Eg and PL correlations

NASA Astrophysics Data System (ADS)

Kumar, Ajit; Verma, Sanjay K.; Alvi, P. A.; Jasrotia, Dinesh

2016-04-01

The nanospatial morphological features of [ZnCl]- [C5H4NCH3]+ hybrid derivative depicts 28 nm granular size and 3D spreader shape packing pattern as analyzed by FESEM and single crystal XRD structural studies. The organic moiety connect the inorganic components through N-H+…Cl- hydrogen bond to form a hybrid composite, the replacement of organic derivatives from 2-methylpyridine to 2-Amino-5-choloropyridine results the increase in granular size from 28nm to 60nm and unit cell packing pattern from 3D-2D lattice dimensionality along ac plane. The change in optical energy direct band gap value from 3.01eV for [ZnCl]- [C5H4NCH3]+ (HM1) to 3.42eV for [ZnCl]- [C5H5ClN2]+ (HM2) indicates the role of organic moiety in optical properties of hybrid materials. The photoluminescence emission spectra is observed in the wavelength range of 370 to 600 nm with maximum peak intensity of 9.66a.u. at 438 nm for (HM1) and 370 to 600 nm with max peak intensity of 9.91 a.u. at 442 nm for (HM2), indicating that the emission spectra lies in visible range. PL excitation spectra depicts the maximum excitation intensity [9.8] at 245.5 nm for (HM1) and its value of 9.9 a.u. at 294 nm, specify the excitation spectra lies in UV range. Photoluminescence excitation spectra is observed in the wavelength range of 280 to 350 nm with maximum peak intensity of 9.4 a.u. at 285.5 nm and 9.9 a.u. at 294 and 297 nm, indicating excitation in the UV spectrum. Single crystal growth process and detailed physiochemical characterization such as XRD, FESEM image analysis photoluminescence property reveals the structure stability with non-covalent interactions, lattice dimensionality (3D-2D) correlations interweaving into the design of inorganic-organic hybrid materials.

Low-Bandgap Cs4CuSb2Cl12 Layered Double Perovskite: Synthesis, Reversible Thermal Changes, and Magnetic Interaction.

PubMed

Singhal, Nancy; Chakraborty, Rayan; Ghosh, Prasenjit; Nag, Angshuman

2018-05-29

Double perovskites (DPs) with a generic formula A2M'(I)M(III)X6 (A and M are metal ions, and X = Cl, Br, I) are now being explored as potential alternatives to Pb-halide perovskite for solar cell and other optoelectronic applications. However, these DPs typically suffer from wide (~ 3 eV) and/or indirect band gaps. In 2017, a new structural variety, namely layered DP halide Cs4CuSb2Cl12 (CCSC) with bivalent Cu(II) ion in place of M'(I) was reported exhibiting a band gap ~1 eV. Here, we report a mechanochemical synthesis of CCSC, its thermal- and chemical stability, and magnetic response of Cu(II) d9 electrons controlling optoelectronic properties. A simple grinding of precursor salts at ambient conditions provides stable and scalable product CCSC. CCSC is stable in water-acetone solvent mixture (~30% water) and many other polar solvents unlike Pb-halide perovskites. It decomposes to Cs3Sb2Cl9, Cs2CuCl4 and SbCl3 at 210 oC, but the reaction can be reversed back to produce CCSC at lower temperatures and high humidity. A long range magnetic ordering is observed in CCSC even at room temperature. Role of such magnetic ordering in controlling the dispersion of conduction band, and therefore, controlling the electronic and optoelectronic properties of CCSC has been discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Halide anion effects on coordination polymerization of cadmium(II) halide with 1: 1 mixed ligands

NASA Astrophysics Data System (ADS)

Ryu, Minjoo; Lee, Young-A.; Jung, Ok-Sang

2018-05-01

Insight into self-assembly of CdX2 (X = Cl and Br) with a mixture of L1 and L2 (L1 = diallylbis(3-pyridyl)silane; L2 = diallylbis(4-pyridyl)silane) was carried out. The self-assembly of CdCl2 with the 1: 1 mixture of L1 and L2 produces only 2D [CdCl2(L1)(L2)] with heteroleptic ligands, whereas that of CdBr2 with the 1: 1 mixture of L1 and L2 gives rise to the statistical mixture of 2D sheet [CdBr2(L1)2]·2H2O, 1D loop-chain [CdBr2(L2)2]·2CH2Cl2, and the 2D [CdBr2(L1)(L2)] with heteroleptic ligands.

Study on Potential Clostridium Botulinum Growth and Toxin Production in Parma Ham

PubMed Central

Ramini, Mattia; Parolari, Giovanni; Barbuti, Silvana; Frustoli, Maria Angela; Taddei, Roberta; Pongolini, Stefano; Ardigò, Paolo; Cozzolino, Paolo

2016-01-01

The objective of this study was to investigate Clostridium botulinum growth and toxin production in the industrially manufactured Italian Parma ham. The study focuses on the Parma ham production phase identified as maximum risk to C. botulinum proliferation, i.e. the transition from cold phase (salting and resting) to a phase carried out at temperature between 15 and 23°C (drying). A preliminary in vitro test was carried out in order to verify the capability of 6 C. botulinum strains (1 type A, 4 type B, and 1 type E strains) to grow in conditions of temperature, pH and NaCl concentration comparable to those of the beginning stage of ham drying. Five C. botulinum strains grew at 20°C and pH 6, four strains produced toxin when inoculated at a concentration equal to 103 cfu/mL at NaCl concentration of 4%, while when the inoculum concentration was 10 cfu/mL, NaCl concentration of 3% resulted the toxin-genesis limiting factor. An experimental contamination with a mixture of the 5 C. botulinum strains selected by the preliminary in vitro test was performed on 9 thighs inoculated at the end of the resting phase. The study was designed to evaluate the potential growth and toxin production in extremely favourable conditions for the bacterium. Type B proteolytic C. botulinum toxin was produced after 14 days of incubation at 20°C in 2 thighs characterised by high weight, low number of days of resting and anomalous physiochemical characteristics [one for very low NaCl concentration (1.59%), the other for elevated pH (6.27) and both for high water activity values (>0.970)]. The results of this research confirm that the cold resting step is a critical phase in the production process of Parma ham for the investigated hazard. Based on the present study, the long resting phase adopted in the manufacturing of Parma ham is proven effective to prevent the growth of C. botulinum, an event which could not otherwise be excluded if the hams were processed under less stringent technological conditions. PMID:27800441

H2O activity in concentrated NaCl solutions at high pressures and temperatures measured by the brucite-periclase equilibrium

NASA Astrophysics Data System (ADS)

Aranovich, L. Y.; Newton, R. C.

1996-10-01

H2O activities in concentrated NaCl solutions were measured in the ranges 600° 900° C and 2 15 kbar and at NaCl concentrations up to halite saturation by depression of the brucite (Mg(OH)2) periclase (MgO) dehydration equilibrium. Experiments were made in internally heated Ar pressure apparatus at 2 and 4.2 kbar and in 1.91-cm-diameter piston-cylinder apparatus with NaCl pressure medium at 4.2, 7, 10 and 15 kbar. Fluid compositions in equilibrium with brucite and periclase were reversed to closures of less than 2 mol% by measuring weight changes after drying of punctured Pt capsules. Brucite-periclase equilibrium in the binary system was redetermined using coarsely crystalline synthetic brucite and periclase to inhibit back-reaction in quenching. These data lead to a linear expression for the standard Gibbs free energy of the brucite dehydration reaction in the experimental temperature range: ΔG° (±120J)=73418 134.95 T(K). Using this function as a baseline, the experimental dehydration points in the system MgO-H2O-NaCl lead to a simple systematic relationship of high-temperature H2O activity in NaCl solution. At low pressure and low fluid densities near 2 kbar the H2O activity is closely approximated by its mole fraction. At pressures of 10 kbar and greater, with fluid densities approaching those of condensed H2O, the H2O activity becomes nearly equal to the square of its mole fraction. Isobaric halite saturation points terminating the univariant brucite-periclase curves were determined at each experimental pressure. The five temperature-composition points in the system NaCl-H2O are in close agreement with the halite saturation curves (liquidus curves) given by existing data from differential thermal analysis to 6 kbar. Solubility of MgO in the vapor phase near halite saturation is much less than one mole percent and could not have influenced our determinations. Activity concentration relations in the experimental P-T range may be retrieved for the binary system H2O-NaCl from our brucite-periclase data and from halite liquidus data with minor extrapolation. At two kbar, solutions closely approach an ideal gas mixture, whereas at 10 kbar and above the solutions closely approximate an ideal fused salt mixture, where the activities of H2O and NaCl correspond to an ideal activity formulation. This profound pressure-induced change of state may be characterized by the activity ( a) concentration ( X) expression: a H 2O= X H 2O/(1+α X NaCl), and a NaCl=(1+α)(1+α)[ X NaCl/(1+α X NaCl)](1+α). The parameter α is determined by regression of the brucite-periclase H2O activity data: α=exp[A B/ϱH 2O ]-C P/ T, where A=4.226, B=2.9605, C=164.984, and P is in kbar, T is in Kelvins, and ϱH 2O is the density of H2O at given P and T in g/cm3. These formulas reproduce both the H2O activity data and the NaCl activity data with a standard deviation of ±0.010. The thermodynamic behavior of concentrated NaCl solutions at high temperature and pressure is thus much simpler than portrayed by extended Debye-Hückel theory. The low H2O activity at high pressures in concentrated supercritical NaCl solutions (or hydrosaline melts) indicates that such solutions should be feasible as chemically active fluids capable of coexisting with solid rocks and silicate liquids (and a CO2-rich vapor) in many processes of deep crustal and upper mantle metamorphism and metasomatism.

Advanced H2-HCl Gas Dynamic Laser, Phase 2

DTIC Science & Technology

1976-01-01

1 3.5.11 Us • 3.969 N2H5N03 33.661 Zr 44.370 HDB 18 NH4C104 2817 33.2 12.6 94.8 ^ 3.5.12 23.808 N2H5N03 34.267 Zr 31.825 HDB 6 ZrCl4 2831...98.2 3.7.3 13.317 NH.CIO. 4 4 20.677 Zr 66.006 HDB 2394 50.6 15.6 98.8 3.7.4 13.586 NH.CIO. 4 4 19.921 Zr 63.493 HDB . 3 ZrCl4 2393 32.9 17.0...CANDIDATE PROPELLANTS Composition 3.3.4 Specie CL H H2 NH3 N2 OH ZRN8 ZRCL4 NH2 ZRCL3 HC1 H20 ZRCL2 ZR028 T °K Chamber Throat Specie

A New Green Chemical Synthesis Strategy for Synthesis of L10 FePt Nanoparticles from Layered Precursor Fe(H2O)6PtCl6

NASA Astrophysics Data System (ADS)

Hadjipanayis, George; Hu, Xiaocao; Capobianchi, Aldo; Gallagher, Ryan

2014-03-01

In this work, a new green chemical strategy for the synthesis of L10 FePt nanoparticles is reported. The starting material is a polycrystalline molecular complex (Fe(H2O)6PtCl6) , in which Fe and Pt atoms are arranged on alternating planes. The starting compound was milled with crystalline NaCl and then annealed under forming gas (5 % H2 and 95 % Ar) at 450 °C for 2h. Finally, the mixture was washed with water to remove the NaCl and L10 FePt nanoparticles were obtained. Transmission electron microscopy (TEM) images revealed that this method is able to produce L10 nanoparticles with different average size varying from 13.9 nm to 5.4 nm depending on the (Fe(H2O)6PtCl6) /NaCl ratio. With smaller (Fe(H2O)6PtCl6) /NaCl ratio(10mg/20g) and longer milling time(15h), FePt nanoparticles had a smaller size and narrower size distribution. The X-Ray Diffraction (XRD) pattern showed the presence of the characteristic peaks of the fct phase. The hysteresis loop, measured both at room temperature and 50 K, shows a high coercivity of 7.6 kOe and 11.2 kOe, respectively as expected for the high anisotropy L10 phase. Larger precursor/NaCl ratio and shorter ball milling time led to larger coercivity.

Quantifying Short-Chain Chlorinated Paraffin Congener Groups.

PubMed

Yuan, Bo; Bogdal, Christian; Berger, Urs; MacLeod, Matthew; Gebbink, Wouter A; Alsberg, Tomas; de Wit, Cynthia A

2017-09-19

Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are referred to as a "congener group" C n Cl m . Recently, we resolved individual C n Cl m by mathematically deconvolving soft ionization high-resolution mass spectra of SCCP mixtures. Here we extend the method to quantifying C n Cl m by introducing C n Cl m specific response factors (RFs) that are calculated from 17 SCCP chain-length standards with a single carbon chain length and variable chlorination level. The signal pattern of each standard is measured on APCI-QTOF-MS. RFs of each C n Cl m are obtained by pairwise optimization of the normal distribution's fit to the signal patterns of the 17 chain-length standards. The method was verified by quantifying SCCP technical mixtures and spiked environmental samples with accuracies of 82-123% and 76-109%, respectively. The absolute differences between calculated and manufacturer-reported chlorination degrees were -0.9 to 1.0%Cl for SCCP mixtures of 49-71%Cl. The quantification method has been replicated with ECNI magnetic sector MS and ECNI-Q-Orbitrap-MS. C n Cl m concentrations determined with the three instruments were highly correlated (R 2 > 0.90) with each other.

Crystal Structure and Magnetic Behavior of Two New Dinuclear Carbonato-Bridged Copper(II) Compounds. Superexchange Pathway for the Different Coordination Modes of the Carbonato Bridge in Polynuclear Copper(II) Compounds.

PubMed

Escuer, Albert; Mautner, Franz A.; Peñalba, Evaristo; Vicente, Ramon

1998-08-24

Four new &mgr;-CO(3)(2-) copper(II) complexes with different coordination modes for the carbonato bridge have been obtained by fixation of atmospheric CO(2): {(&mgr;(3)-CO(3))[Cu(3)(ClO(4))(3)(Et(3)dien)(3)]}(ClO(4)) (1), Et(3)dien = N,N',N"-triethylbis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(Et(4)dien)(2)]}(ClO(4))(2).H(2)O (2), Et(4)dien = N,N,N",N"-tetraethyl-bis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(2)(EtMe(4)dien)(2)]} (ClO(4))(2).2H(2)O (3), EtMe(4)dien = N'-ethyl-N,N,N",N"-tetramethylbis(2-aminoethane)amine; and {(&mgr;-CO(3))[Cu(2)(H(2)O)(Me(5)dien)(2)]}(ClO(4))(2).H(2)O (4), Me(5)dien = N,N,N',N",N"-pentamethylbis(2-aminoethane)amine. The crystal structures have been solved for 2, monoclinic system, space group P2(1)/n, formula [C(25)H(62)Cl(2)Cu(2)N(6)O(13)] with a = 12.763(6) Å, b = 25.125(8) Å, c = 13.261(4) Å, beta = 111.85(3) degrees, Z = 4, and for 3, triclinic system, space group P&onemacr;, formula [C(21)H(58)Cl(2)Cu(2)N(6)O(15)] with a = 8.412(3) Å, b = 14.667(4) Å, c = 16.555(5) Å, alpha = 99.66(2) degrees, beta = 102.14(2) degrees, gamma = 104.72(2) degrees, Z = 2. Susceptibility measurements show ferromagnetic behavior (J = +6.7(6) cm(-)(1)) for the trinuclear compound 1 whereas 2-4 are antiferromagnetically coupled with J = -17.8(8), -125.5(9), and -21.2(3) cm(-)(1) respectively. Certain synthetic aspects that may be related to the nuclearity of the copper(II) &mgr;-CO(3)(2-) compounds and the superexchange pathway for the different coordination modes of the carbonato bridge are discussed.

Effects of Coordinating a Hemilabile Ligand to 14e Cp*M(NO) Scaffolds (M = Mo, W).

PubMed

Handford, Rex C; Patrick, Brian O; Legzdins, Peter

2017-10-16

This article describes the differing chemical properties imparted by the two ligands, hemilabile 2-[(diisopropylphosphino)methyl]-3-methylpyridine ( i Pr 2 PN) and the related 1,2-bis(dimethylphosphino)ethane (dmpe), when attached to the 14e Cp*M(NO) scaffolds (Cp* = η 5 -C 5 Me 5 ; M = W, Mo). For instance, the treatment of [Cp*W(NO)Cl 2 ] 2 with 2 or 1 equiv of dmpe in C 6 H 6 affords excellent yields of [Cp*W(NO)(κ 2 -dmpe)Cl]Cl (1) or [Cp*W(NO)Cl 2 ] 2 [μ-dmpe] (2). In contrast, the treatment of [Cp*W(NO)Cl 2 ] 2 with 1 equiv of i Pr 2 PN in C 6 H 6 does not produce the complex analogous to 1 but rather affords orange [Cp*W(NO)(κ 2 -P-N- i Pr 2 PN)Cl][Cp*W(NO)Cl 3 ] (3) in 90% yield. Furthermore, subsequent reduction of 1 or 2 with 2 or 4 equiv of Cp 2 Co in tetrahydrofuran (THF), respectively, results in the production of orange Cp*W(NO)(κ 2 -dmpe) (4) in good yields. However, a similar treatment of 3 with 1 equiv of Cp 2 Co in THF does not result in the production of Cp*W(NO)(κ 2 -P,N- i Pr 2 PN), the analogue of 4, but rather generates a 1:1 mixture of the novel complexes Cp*W(NO)(H)(κ 1 -P- i Pr 2 PN)Cl (5) and Cp*W(NO)(κ 2 -P,N- i Pr 2 PCH-2-(3-Me-C 5 H 3 N))Cl (6), which are separable by crystallization from pentane and diethyl ether solutions, respectively. The divergent reactivity imparted by the dmpe and i Pr 2 PN proligands is a unique demonstration of the unusual properties of a mixed-donor ligand. In the case of molybdenum, the reaction of [Cp*Mo(NO)Cl 2 ] 2 with 2 equiv of i Pr 2 PN in C 6 H 6 first forms Cp*Mo(NO)(κ 1 -P- i Pr 2 PN)Cl 2 , which then converts to [Cp*Mo(NO)(κ 2 -P,N- i Pr 2 PN)Cl][Cp*Mo(NO)Cl 3 ], the analogue of 3. Reduction of the Cp*Mo(NO)(κ 1 -P- i Pr 2 PN)Cl 2 intermediate complex with 2 equiv of Cp 2 Co affords dark-green Cp*Mo(NO)(κ 2 -P,N- i Pr 2 PN) (7). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.

Selective methane chlorination to methyl chloride by zeolite Y-based catalysts

NASA Astrophysics Data System (ADS)

Joo, Hyeonho; Kim, Daeho; Lim, Kwang Soo; Choi, Yong Nam; Na, Kyungsu

2018-03-01

The CH4 chlorination over Y zeolites was investigated to produce CH3Cl in a high yield. Three different catalytic systems based on Y zeolite were tested for enhancement of CH4 conversion and CH3Cl selectivity: (i) HY zeolites in H+-form having various Si/Al ratios, (ii) Pt/HY zeolites supporting Pt metal nanoparticles, (iii) Pt/NaY zeolites in Na+-form supporting Pt metal nanoparticles. The reaction was carried out using the gas mixture of CH4 and Cl2 with the respective flow rates of 15 and 10 mL min-1 at 300-350 °C using a fixed-bed reactor under a continuous gas flow condition (gas hourly space velocity = 3000 mL g-1 h-1). Above the reaction temperature of 300 °C, the CH4 chlorination is spontaneous even in the absence of catalyst, achieving 23.6% of CH4 conversion with 73.4% of CH3Cl selectivity. Under sufficient supplement of thermal energy, Cl2 molecules can be dissociated to two chlorine radicals, which triggered the C-H bond activation of CH4 molecule and thereby various chlorinated methane products (i.e., CH3Cl, CH2Cl2, CHCl3, CCl4) could be produced. When the catalysts were used under the same reaction condition, enhancement in the CH4 conversion was observed. The Pt-free HY zeolite series with varied Si/Al ratios gave around 27% of CH4 conversion, but there was a slight decrease in CH3Cl selectivity with about 64%. Despite the difference in acidity of HY zeolites having different Si/Al ratios, no prominent effect of the Si/Al ratios on the catalytic performance was observed. This suggests that the catalytic contribution of HY zeolites under the present reaction condition is not strong enough to overcome the spontaneous CH4 chlorination. When the Pt/HY zeolite catalysts were used, the CH4 conversion reached further up to 30% but the CH3Cl selectivity decreased to 60%. Such an enhancement of CH4 conversion could be attributed to the strong catalytic activity of HY and Pt/HY zeolite catalysts. However, both catalysts induced the radical cleavage of Cl2 more favorably, which ultimately decreased the CH3Cl selectivity. Such trade-off relationship between CH4 conversion and CH3Cl selectivity can be slightly broken by using Pt/NaY zeolite catalyst that is known to possess Frustrated Lewis Pairs (FLP) that are very useful for ionic cleavage of H2 to H+ and H-. Similarly, in the present work, Pt/NaY(FLP) catalysts enhanced the CH4 conversion while keeping the CH3Cl selectivity as compared to the Pt/HY zeolite catalysts.

Corrosion-Control (CC) Program: Pilot Powder Coating Station Service Test.

DTIC Science & Technology

1986-03-14

o CL oU C4 CL00 z ;,S Go 0 m~ CL - C9 uj4 U..~D o . ZC.F Go zz 2 0 I- - c t < m U, cc V V4 cg c ~ D GD...Spray Booth# Curing Oven and A2-58 UNIT TOTAL is_18 A2-1 1WOW - o 0 -1 Q S re. 10 U c Z. 2E E. a.E 8 tE 20 4AU ==- %A a 4 $AO - Lo 48 0 w 0 -IL .. 0.... 0...Laa 00 3-r Q’ IA E zo 0..0 -< 4o C a) Ia - o x c bi. l c *4 ’a a~~* coLo. 0V Ua- 41 w - a V 2 2 .8 h A a U to bo co i ac

A Layered Solution Crystal Growth Technique and the Crystal Structure of (C 6H 5C 2H 4NH 3) 2PbCl 4

NASA Astrophysics Data System (ADS)

Mitzi, D. B.

1999-07-01

Single crystals of the organic-inorganic perovskite (C6H5C2H4NH3)2PbCl4 have been grown at room temperature using a layered solution approach. The bottom solution layer, contained within a long straight tube, consists of PbCl2 dissolved in concentrated aqueous HCl. A less dense layer of methanol is carefully placed on top of the HCl/PbCl2 solution using a syringe. Finally, a stoichiometric quantity of C6H5C2H4NH2 (relative to the PbCl2) is added to the top of the column. As the layers slowly diffuse together, well-formed crystals of (C6H5C2H4NH3)2PbCl4 appear near the interface between the HCl/PbCl2 and C6H5C2H4NH2 solutions. The thick, plate-like crystals are well suited for X-ray crystallography studies. Room temperature intensity data were refined using a triclinic (Poverline1) cell (a=11.1463(3) Å, b=11.2181(3) Å, c=17.6966(5) Å, α= 99.173(1)°, β=104.634(1)°, γ=89.999(1)°, V=2111.8(1) Å3, Z=4, Rf/Rw=0.031/0.044). The organic-inorganic layered perovskite structure features well-ordered sheets of corner-sharing distorted PbCl6 octahedra separated by bilayers of phenethylammonium cations. Tilting and rotation of the PbCl6 octahedra within the perovskite sheets, coupled with organic cation ordering, leads to the unusual in-sheet 2ap×2ap superstructure, where ap is the lattice constant for the ideal cubic perovskite.

Amp Synthesis in Aqueous Solution of Adenosine and Phosphorus Pentoxide

NASA Astrophysics Data System (ADS)

Yamagata, Y.; Kojima, H.; Ejiri, K.; Inomata, K.

1982-12-01

Possible formation of a P4O10 molecule in magma, the stability of the molecule in hydrous volcanic gas at high temperatures and a possible prebiotic phosphate cycle were discussed in relation to chemical evolution. To demonstrate the utility of phosphorus pentoxide as a phosphorylating agent, aqueous solutions of adenosine (0.02M) and phosphorus pentoxide (0.2M) were incubated at 37°C for 5 months. The pH of the solutions was adjusted every day or every few days to each fixed value (9.0, 10.5, 11.5, 12.5) with 10 N NaOH. The HPLC analysis showed the formation of 2'-AMP, 3'-AMP, 5'-AMP, cyclic (2' 3')-AMP and cyclic (3' 5')-AMP. The main components of the products were 2'- and 3'-AMP, though cyclic (2' 3')-AMP was the main component in the early period of the incubation at pH 9.0. The yields (conversion rate of adenosine to AMPs) were increased almost linearly with the incubation time for 5 months in the case of pH 9.0. The final yields were about 3% (pH 9.0), 6% (pH 9.0, 1 M NaCl), 5% (pH 9.0, 0.01 M CaCl2, 0.01 M MgCl2), 7% (pH 9.0, 0.5 M NaCl, 0.01 M CaCl2, 0.01 M MgCl2), 9% (pH 9.0, 1 M NaCl, 0.01 M CaCl2, 0.01 M MgCl2), 32% (pH 10.5), 43% (pH 11.5), 35% (pH 12.5).

Kinetic disposition of lorazepam with focus on the glucuronidation capacity, transplacental transfer in parturients and racemization in biological samples.

PubMed

Papini, Olga; da Cunha, Sergio Pereira; da Silva Mathes, Angelo do Carmo; Bertucci, Carlo; Moisés, Elaine Christine Dantas; de Barros Duarte, Luciana; de Carvalho Cavalli, Ricardo; Lanchote, Vera Lucia

2006-02-13

The present study investigates the kinetic disposition with focus on the racemization, glucuronidation capacity and the transplacental transfer of lorazepam in term parturients during labor. The study was conducted on 10 healthy parturients aged 18-37 years with a gestational age of 36-40.1 weeks, treated with a single oral dose of 2 mg racemic lorazepam 2-9 h before delivery. Maternal venous blood and urine samples were obtained over a 0-48 h interval and the umbilical cord sample was obtained immediately after clamping. Lorazepam enantiomers were determined in plasma and urine samples by LC-MS/MS using a Chiralcel OD-R column. In vitro racemization of lorazepam required the calculation of the pharmacokinetic parameters as isomeric mixtures. The data were fitted to two-compartment model and the pharmacokinetic parameters are reported as means (95% CI): t(1/2a) 3.2h (2.6-3.7 h), K(a) 0.23 h(-1) (0.19-0.28 h(-1)), t(1/2) 10.4h (9.4-11.3h), beta 0.068 h(-1) (0.061-0.075h(-1)), AUC(0-infinity) 175.3(ngh)/ml (145.7-204.8(ngh)/ml), Cl/F 2.6 ml/(minkg) (2.3-2.9 ml/(minkg)), Vd/F178.8l (146.5-211.1l), Fel 0.3% (0.1-0.5%), and Cl(R) 0.010 ml/(minkg) (0.005-0.015 ml/(minkg)). Placental transfer of lorazepam evaluated as the ratio of vein umbilical/maternal vein plasma concentrations, obtained as an isomeric mixture, was 0.73 (0.52-0.94). Pregnancy changes the pharmacokinetics of lorazepam, with an increase in the apparent distribution volume, an increase in apparent oral clearance, and a reduction of elimination half-life. The increase in oral clearance may indicate an increase in glucuronidation capacity, with a possible reduction in the plasma concentrations of drugs depending on glucuronidation capacity as the major metabolic pathway.

Determining the partial photoionization cross-sections of ethyl radicals.

PubMed

FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

2007-12-13

Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

Prime Contractors with Awards over $25,000 by Name, Location, and Contract Number. Part 6 (RGI Inc, San Diego, California -- Technology Specialist Inc, Arlington, Virginia), FY1991

DTIC Science & Technology

1991-01-01

L) W z WU- L) .4 WCl)L3( 0 WWW < WW W 0i z m I 0 I= 4 C4cc( IU3 U 4n z L) Uz C) 4 Z UZ u -) Utz 0 U 0 0 I -C U 4 U; I4 Cl aW L, L) W9 nE 0- 0 U3W...0 0 I ~ 1j ~ 0> ix ( 0m.- LI)1. (n 0. Z3 Li -C En LI :1 I’" T, CL, 4H H L) Www I L r u - 0- 0 . 0. 8 . > 0 0:000: 104. 10 N0 ) 0 LI L C.4 I L 0 1.. H...m M 0c A 04 4 .4 042 . CC u U) 0 439 4 a.Z-M a 0 C z 4 www 0O > 0~ L) oH 0 g 2 > cn L) 0 44 0 0 Su~A 08 U3H 0 . Z w.~4. CO~ W ’OCCOO) f OC)OC ix0< HI

Prime Contract Awards of $100,000 or More by Federal Supply Classification or Service Category and Purchasing Office. Part 2 (5450-9999)

DTIC Science & Technology

1989-01-01

af a>o - o CL -4 0-u< m - CLO. -4 0 WC -4 M b c CLC 0 )U"aCV C 0L > 4 .t 0 0L 0 " .0." ID0ZW W4 .0 04q 4- I- H 00CL1 0 CC, 0U) 0L >-1 ~3 CL EU ) ɜ...E0 0 E E U a 4-43H ~ U 0 MO 000 af ) H) o 00W 00 0 U) 0 00000 0 w -J f-L U- 0’ O () 00 a) Z -J cl -4 0) -1 (n <-0 40 0 -j -4 4 -l000-4 000N1 -AC 4- -4 L...uL )L)U :fL- _ L CLO CL𔃾--- CL C - 0. L1- - LUUC C CA oO0ooCL -. Cl0 C-. Ovcn0 WUC -j L0_0 $1 >L)0 U -4 Ec - 0)( ( o( af 0. CL M 2u )(1) L c ) L L

Self-assembly of chiral molecular polygons.

PubMed

Jiang, Hua; Lin, Wenbin

2003-07-09

Treatment of 2,2'-diacetyl-1,1'-binaphthyl-6,6'-bis(ethyne), L-H2, with 1 equiv of trans-Pt(PEt3)2Cl2 led to a mixture of different sizes of chiral metallocycles [trans-(PEt3)2Pt(L)]n (n = 3-8, 1-6). Each of the chiral molecular polygons 1-6 was purified by silica gel column chromatography and characterized by 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, MS, IR, UV-vis, and circular dichroism spectroscopies, and microanalysis. The presence of tunable cavities (1.4-4.3 nm) and chiral functionalities in these molecular polygons promises to make them excellent receptors for a variety of guests.

Synthesis, crystal structure and high temperature phase transition in the new organic-inorganic hybrid [N(C4H9)4]3Zn2Cl7H2O crystals

NASA Astrophysics Data System (ADS)

Ben Gzaiel, Malika; Oueslati, Abderrazek; Lhoste, Jérôme; Gargouri, Mohamed; Bulou, Alain

2015-06-01

The present paper accounts for the synthesis, crystal structure, differential scanning calorimetry and vibrational spectroscopy of a new compound tri-tetrabutylammonium heptachloro-dizincate (I) grown at room temperature by slow evaporation of aqueous solution. From X-ray diffraction data collected at room temperature, it is concluded that it crystallizes in the monoclinic system (P21/n space group) containing ZnCl42- and ZnCl3H2O1- tetrahedra. The atomic arrangement can be described by an alternation of organic and organic-inorganic layers stacked along the c direction. Differential scanning calorimetry (DSC) in the range 250-450 K disclosed a reversible structural phase transition of order-disorder type at 358 K, prior to the melting at 395 K. The temperature dependence of the Raman spectra of [N(C4H9)4]3Zn2Cl7H2O single crystals was studied in the spectral range 100-3500 cm-1 and for temperatures between 300 and 386 K. The most important changes are observed for the line at 261 cm-1 issued from ν1(ZnCl4). The analysis of the wavenumber, intensity and the line width based on an order-disorder model allowed to obtain information relative to the activation energy and the correlation length. The decrease of the activation energy with increasing temperature has been interpreted in term of a change in the re-orientation motion of the anionic parts. The assumption of cluster fluctuations also allowed the critical exponents to be obtained for the transition δ = 0.011 and the correlation length ξ0 = 598 Å.

1-Chlorobutane

Integrated Risk Information System (IRIS)

1 - Chlorobutane ; CASRN 109 - 69 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

Chanabayaite, Cu2(N3C2H2)Cl(NH3,Cl,H2O,□)4, a new mineral containing triazolate anion

NASA Astrophysics Data System (ADS)

Chukanov, N. V.; Zubkova, N. V.; Möhn, G.; Pekov, I. V.; Pushcharovsky, D. Yu.; Zadov, A. E.

2015-12-01

A new mineral, chanabayaite, has been discovered at a guano deposit located at Mt. Pabellón de Pica near the village of Chanabaya, Iquique Province, Tarapacá region, Chile. It is associated with salammoniac, halite, joanneumite, nitratine and earlier chalcopyrite. Chanabayaite occurs as blue translucent imperfect prismatic crystals, up to 0.05 × 0.1 × 0.5 mm in size, and their radial aggregates. Chanabayaite is brittle, with a Mohs' hardness of 2. The cleavage is perfect on (001) and imperfect on (100) and (010). D meas = 1.48(2) g/cm3, D calc = 1.464 g/cm3. The mineral is optically biaxial (-), α = 1.561(2), β = 1.615(3), γ = 1.620(2), 2 V meas = 25(10)°, 2 V calc = 33°. Pleochroism is strong, Z ≈ Y (deep blue) ≫ X (pale blue with gray tint). IR spectrum is given. The chemical composition (electron microprobe data for Cu, Fe and Cl; gas chromatography data for H, N, C and O) is as follows (wt %): 32.23 Cu, 1.14 Fe, 16.13 Cl, 3.1 H, 29.9 N, 12.2 C, 3.4 O, total is 98.1. The empirical formula is ( Z = 4): Cu1.92Fe0.08Cl1.72N8.09C3.85H11.66O0.81. The structural model was based on the single-crystal X-ray diffraction data ( R = 0.1627). Chanabayaite is orthorhombic, space group Imma, a = 19.484(3), b = 7.2136(10), c = 11.999(4) Å, V = 1686.5(7) Å3, Z = 2. In chanabayaite, chains of the corner-sharing Cu(l)-centered octahedra and single Cu(2)-centered octahedra are linked via 1,2,4-triazolate anions C2N3H2 -. NH3 and Cl- are additional ligands coordinating Cu2+. Chanabayaite is a transformational mineral species formed by leaching of Na and one third of Cl and partial dehydration of the protophase Na2Cu2Cl3(N3C2H2)2(NH3)2 • 4H2O. The strongest reflections in the powder X-ray diffraction pattern [ d, Å ( I, %) ( hkl)] are detected: 10.19 (100) (101), 6.189 (40) (011), 5.729 (23) (301), 5.216 (75) (211, 202), 4.964 (20) (400), 2.830 (20) (602, 413, 503), 2.611 (24) (123, 422, 404).

Burkholderia dipogonis sp. nov., isolated from root nodules of Dipogon lignosus in New Zealand and Western Australia.

PubMed

Sheu, Shih-Yi; Chen, Ming-Hui; Liu, Wendy Y Y; Andrews, Mitchell; James, Euan K; Ardley, Julie K; De Meyer, Sofie E; James, Trevor K; Howieson, John G; Coutinho, Bruna G; Chen, Wen-Ming

2015-12-01

Seven strains, ICMP 19430T, ICMP 19429, ICMP 19431, WSM4637, WSM4638, WSM4639 and WSM4640, were isolated from nitrogen-fixing nodules on roots of the invasive South African legume Dipogon lignosus (subfamily Papilionoideae, tribe Phaseoleae) in New Zealand and Western Australia, and their taxonomic positions were investigated by using a polyphasic approach. All seven strains grew at 10-37 °C (optimum, 25-30 °C), at pH 4.0-9.0 (optimum, pH 6.0-7.0) and with 0-2 % (w/v) NaCl (optimum growth in the absence of NaCl). On the basis of 16S rRNA gene sequence analysis, the strains showed 99.0-99.5 % sequence similarity to the closest type strain, Burkholderia phytofirmans PsJNT, and 98.4-99.7 % sequence similarity to Burkholderia caledonica LMG 19076T. The predominant fatty acids were C18 : 1ω7c (21.0 % of the total fatty acids in strain ICMP 19430T), C16 : 0 (19.1 %), C17 : 0 cyclo (18.9 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 10.7 %) and C19 : 0 cyclov ω8c (7.5 %). The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized aminophospholipids and phospholipids. The major isoprenoid quinone was Q-8 and the DNA G+C content of strain ICMP 19430T was 63.2 mol%. The DNA–DNA relatedness of the novel strains with respect to the closest neighbouring members of the genus Burkholderia was 55 % or less. On the basis of 16S rRNA and recA gene sequence similarities and chemotaxonomic and phenotypic data,these strains represent a novel symbiotic species in the genus Burkholderia, for which the name Burkholderia dipogonis sp. nov. is proposed, with the type strain ICMP 19430T (=LMG28415T=HAMBI 3637T).

A high-throughput method to measure NaCl and acid taste thresholds in mice.

PubMed

Ishiwatari, Yutaka; Bachmanov, Alexander A

2009-05-01

To develop a technique suitable for measuring NaCl taste thresholds in genetic studies, we conducted a series of experiments with outbred CD-1 mice using conditioned taste aversion (CTA) and two-bottle preference tests. In Experiment 1, we compared conditioning procedures involving either oral self-administration of LiCl or pairing NaCl intake with LiCl injections and found that thresholds were the lowest after LiCl self-administration. In Experiment 2, we compared different procedures (30-min and 48-h tests) for testing conditioned mice and found that the 48-h test is more sensitive. In Experiment 3, we examined the effects of varying strength of conditioned (NaCl or LiCl taste intensity) and unconditioned (LiCl toxicity) stimuli and concluded that 75-150 mM LiCl or its mixtures with NaCl are the optimal stimuli for conditioning by oral self-administration. In Experiment 4, we examined whether this technique is applicable for measuring taste thresholds for other taste stimuli. Results of these experiments show that conditioning by oral self-administration of LiCl solutions or its mixtures with other taste stimuli followed by 48-h two-bottle tests of concentration series of a conditioned stimulus is an efficient and sensitive method to measure taste thresholds. Thresholds measured with this technique were 2 mM for NaCl and 1 mM for citric acid. This approach is suitable for simultaneous testing of large numbers of animals, which is required for genetic studies. These data demonstrate that mice, like several other species, generalize CTA from LiCl to NaCl, suggesting that they perceive taste of NaCl and LiCl as qualitatively similar, and they also can generalize CTA of a binary mixture of taste stimuli to mixture components.

Solubility and stability of melatonin in propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles.

PubMed

Lee, B J; Choi, H G; Kim, C K; Parrott, K A; Ayres, J W; Sack, R L

1997-12-01

The physicochemical properties of melatonin (MT) in propylene glycol (PG) and 2-hydroxypropyl-beta-cyclodextrin (2-HPbetaCD) vehicles were characterized. MT was endothermally decomposed as determined by differential scanning calorimetry (DSC). Melting point and heat of fusion obtained were 116.9+/-0.24 degrees C and 7249+/-217 cal/mol, respectively. MT as received from a manufacture was very pure, at least 99.9%. The solubility of MT in PG solution increased slowly until reaching 40% PG and then steeply increased. Solubility of MT increased linearly as concentration of 2-HPbetaCD without PG increased (R(2)=0.993). MT solubility in the mixtures of PG and 2-HPbetaCD also increased linearly but was less than the sum of its solubility in 2-HPbetaCD and PG individually. The MT solubility was low in water, simulated gastric or intestinal fluid but the highest in the mixture of PG (40 v/v%) and 2-HPbetaCD (30 w/v%) although efficiency of MT solubilization in 2-HPbetaCD decreased as the concentration of PG increased. MT was degraded in a fashion of the first order kinetics (r(2)>0.90). MT was unstable in strong acidic solution (HCl-NaCl buffer, pH 1.4) but relatively stable in other pH values of 4 approximately 10 at 70 degrees C. In HCl-NaCl buffer, MT in 10% PG was more quickly degraded and then slowed down at a higher concentration. However, the degradation rate constant of MT in 2-HPbetaCD was not changed significantly when compared to the water. The current studies can be applied to the dosage formulations for the purpose of enhancing percutaneous absorption or bioavailability of MT.

Computational and experimental study of the interactions between ionic liquids and volatile organic compounds.

PubMed

Gao, Tingting; Andino, Jean M; Alvarez-Idaboy, J Raul

2010-09-07

Computational chemistry calculations were performed to investigate the interactions of ionic liquids with different classes of volatile organic compounds (VOCs), including alcohols, aldehydes, ketones, alkanes, alkenes, alkynes and aromatic compounds. At least one VOC was studied to represent each class. Initially, 1-butyl-3-methylimindazolium chloride (abbreviated as C(4)mimCl) was used as the test ionic liquid compound. Calculated interaction lengths between atoms in the ionic liquid and the VOC tested as well as thermodynamic data suggest that C(4)mimCl preferentially interacts with alcohols as compared to other classes of volatile organic compounds. The interactions of methanol with different kinds of ionic liquids, specifically 1-butyl-3-methylimidazolium bromine (C(4)mimBr) and 1-butyl-3-methylimidazolium tetrafluoroborate (C(4)mimBF(4)) were also studied. In comparing C(4)mimCl, C(4)mimBr, and C(4)mimBF(4), the computational results suggest that C(4)mimCl is more likely to interact with methanol. Laboratory experiments were performed to provide further evidence for the interaction between C(4)mimCl and different classes of VOCs. Fourier transform infrared spectroscopy was used to probe the ionic liquid surface before and after exposure to the VOCs that were tested. New spectral features were detected after exposure of C(4)mimCl to various alcohols. The new features are characteristic of the alcohols tested. No new IR features were detected after exposure of the C(4)mimCl to the aldehyde, ketone, alkane, alkene, alkyne or aromatic compounds studied. In addition, after exposing the C(4)mimCl to a multi-component mixture of various classes of compounds (including an alcohol), the only new peaks that were detected were characteristic of the alcohol that was tested. These experimental results demonstrated that C(4)mimCl is selective to alcohols, even in complex mixtures. The findings in this work provide information for future gas-phase alcohol sensor design.

Synthesis and Characterization of the First Cyclic Monothioether Derivative of 1,2-o-Carborane and Its Reactivity toward Phosphine Transition Metal Complexes.

PubMed

Viñas, Clara; Cirera, M. Rosa; Teixidor, Francesc; Kivekäs, Raikko; Sillanpää, Reijo; Llibre, Joan

1998-12-28

The first cyclic monothioether derivative of [C(2)B(9)H(12)](-) has been synthesized from 1-(SH)-1,2-C(2)B(10)H(11). Reaction of the latter with (n)BuLi and 1,3-dibromopropane leads to 1,2-&mgr;-(S(CH(2))(3))-1,2-C(2)B(10)H(10). Partial degradation leads to [7,8-&mgr;-(S(CH(2))(3))-7,8-C(2)B(9)H(10)](-). Reaction of [7,8-&mgr;-(S(CH(2))(3))-7,8-C(2)B(9)H(10)](-) with [PdCl(2)(PRR'(2))(2)] leads to different sets of compounds depending on the nature of R and R'. If R = R' = (t)Bu, a closo compound with one vertex occupied by "[Pd(P(t)Bu(3))(2)]" is obtained. When aryl groups are present in the starting phosphine complex, the zwitterionic non-metal-containing compounds are obtained. The crystal structure of one of them has been determined, and the compound has been proven to be 7,8-&mgr;-(S(CH(2))(3))-11-PPh(3)-7,8-C(2)B(9)H(9). The reaction of [7,8-&mgr;-(S(CH(2))(3))-7,8-C(2)B(9)H(10)](-) with [RhCl(PPh(3))(3)] leads to [Rh(7,8-&mgr;-(S(CH(2))(3))-7,8-C(2)B(9)H(10))(PPh(3))(2)]. An agostic B-Hright harpoon-up Rh interaction has been produced, identified by a (1)H{(11)B} NMR resonance at -4.78 ppm. In this instance the cluster is connected to "Rh" via the thioether and B(11)-H. The reaction of [7,8-&mgr;-(S(CH(2))(3))-7,8-C(2)B(9)H(10)](-) with [RuCl(2)(PPh(3))(3)] leads to a compound with two B-Hright harpoon-up Ru interactions. Contrarily to its noncyclic analogues, it seems that only one isomer has been obtained.

Orthopalladation of iminophosphoranes: synthesis, structure and study of stability.

PubMed

Bielsa, Raquel; Navarro, Rafael; Soler, Tatiana; Urriolabeitia, Esteban P

2008-03-07

The reaction of Pd(OAc)(2) with polyfunctional iminophosphoranes Ph(3)P=NCH(2)CO(2)Me (1a), Ph(3)P=NCH(2)C(O)NMe(2) (1b), Ph(3)P=NCH(2)CH(2)SMe (1c) and Ph(3)P=NCH(2)-2-NC(5)H(4) (1d), gives the orthopalladated dinuclear complex [Pd(mu-Cl){C(6)H(4)(PPh(2)=NCH(2)CO(2)Me-kappa-C,N)-2}](2) (2a) and the mononuclear derivatives [PdCl{C(6)H(4)(PPh(2)=NCH(2)CONMe(2)-kappa-C,N,O)-2}] (2b), [PdCl{C(6)H(4)(PPh(2)=NCH(2)CH(2)SMe-kappa-C,N,S)-2}] (2c) and [PdCl{C(6)H(4)(PPh(2)=NCH(2)-2-NC(5)H(4)-kappa-C,N,N)-2}] (2d). The reaction implies the activation of a C-H bond in a phenyl ring of the phosphonium group, this fact being worthy of note due to the strongly deactivating nature of the phosphonium unit. The palladacycle containing the metallated carbon atom is remarkably stable toward the coordination of incoming ligands, while that formed by the iminic N atom and another heteroatom (O, 2a and 2b; S, 2c; N, 2d) is less stable and the resulting complexes can be considered as hemilabile. The X-ray crystal structures of the cyclopalladated [Pd(mu-Cl){C(6)H(4)(PPh(2)=NCH(2)CO(2)Me-kappa-C,N)-2}](2) (2a), [PdCl{C(6)H(4)(PPh(2)=NCH(2)-2-NC(5)H(4)-kappa-C,N,N)-2}] (2d), [Pd{C(6)H(4)(PPh(2)=NCH(2)CONMe(2)-kappa-C,N,O)-2}(NCMe)](ClO(4)) (7b) and [Pd{C(6)H(4)(PPh(2)NCH(2)CONMe(2)-kappa-C,N,O)-2}(py)](ClO(4)) (3b), and the coordination compound cis-[Pd(Cl)(2)(Ph(3)P=NCH(2)CH(2)SMe-kappa-N,S)] (8) are also reported.

Dichlorido[N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide-κN](1,10-phenanthroline-κ2 N,N′)cobalt(II) methanol monosolvate

PubMed Central

Wang, Yuan; Liu, Zheng; Liu, Baoyu

2009-01-01

In the title compound, [CoCl2(C13H9Cl2N3O2)2(C12H8N2)]·CH3OH, the CoII atom is octahedrally coordinated by two N atoms from the pyridyl rings of the tridentate N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide (H2 L) ligand, two N atoms from the 1,10-phenanthroline ligand and two chloride ions. The acyl­hydrazone groups are not involved into the coordination of the metal ion. In the crystal packing an extended three-dimensional network formed by N—H⋯Cl, N—H⋯O, O—H⋯N, O—H⋯N and O—H⋯Cl hydrogen bonds is observed. PMID:21578623

Different patterns of supramolecular assembly in constitutionally similar 6-arylimidazo[2,1-b][1,3,4]thiadiazoles.

PubMed

Praveen, Aletti S; Yathirajan, Hemmige S; Kaur, Manpreet; Narayana, Badiadka; Hosten, Eric C; Betz, Richard; Glidewell, Christopher

2014-09-01

Four imidazo[2,1-b][1,3,4]thiadiazoles containing a simply-substituted 6-aryl group have been synthesized by reaction of 2-amino-1,3,4-thiadiazoles with bromoacetylarenes using microwave irradiation and brief reaction times. 6-(2-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C(10)H(6)ClN(3)S, (I), 6-(2-chlorophenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C(11)H(8)ClN(3)S, (II), 6-(3,4-dichlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C(10)H(5)Cl(2)N(3)S, (III), and 6-(4-fluoro-3-methoxyphenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C(12)H(10)FN(3)OS, (IV), crystallize with Z' values of 2, 1, 1 and 2 respectively. The molecular skeletons are all nearly planar and the dihedral angles between the imidazole and aryl rings are 1.51 (8) and 7.28 (8)° in (I), 9.65 (7)° in (II), 10.44 (8)° in (III), and 1.05 (8) and 7.21 (8)° in (IV). The molecules in (I) are linked by three independent C-H...N hydrogen bonds to form ribbons containing alternating R2(2)(8) and R4(4)(18) rings, and these ribbons are linked into a three-dimensional array by three independent π-stacking interactions. Both (II) and (III) contain centrosymmetric dimers formed by π-stacking interactions but hydrogen bonds are absent, and the molecules of (IV) are linked into centrosymmetric R2(2)(8) dimers by C-H...N hydrogen bonds. Comparisons are made with a number of related compounds.

Ionothermal synthesis, characterization of a new layered gallium phosphate with an unusual heptamer SBU

NASA Astrophysics Data System (ADS)

Gao, Fan; Huang, Liangliang; Ma, Yike; Jiao, Shufei; Jiang, Yansong; Bi, Yanfeng

2017-10-01

A new layered gallium phosphate Ga3(PO4)4(C2N2H8)·(H2C2N2H8)2·Cl (compound 1), has been ionothermally synthesized in the presence of deep eutectic solvent (DES) comprising mixtures of choline chloride and 2-imidazolidone (IMI). Single-crystal X-ray diffraction analysis reveals that compound 1 shows 2D layered framework with 10-ring windows, which is constructed from unusual heptamer second building units (SBUs). The ethylenediamine (en) units deriving from the decomposition of IMI, play a dual role as bidentate ligands coordinated with 6-fold coordinate gallium atoms and the templates. Additionally, compound 1 shows photoluminescence property in solid state at room temperature.

Synthesis and physico-chemical studies on neodymium(III) and samarium(III) complexes with tetraaza macrocyclic ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goel, S.; Pandey, U.K.; Pandey, O.P.

1988-05-01

Reactions of neodymium trichloride and samarium trichloride with 6,7,13,14-R/sub 4/ - 3,10-X/sub 2/-(14)-5,7,12,14-tetraene-1,5,8,12-N/sub 4/-(2,4,9,11-N/sub 4/) (R = CH/sub 3/, X = 0 (L/sub 1//sup (1)/); R = C/sub 6/H/sub 5/, X = O (L/sub 1//sup (2)/); R = CH/sub 3/, X = S(L/sub 2//sup (1)/)) and R = C/sub 6/H/sub 5/, X = S(/sub 2//sup (2)/)) have been studied in ethanol and complexes of the type (M(L/sub 1//sup (1)/ or L/sub 1//sup (2)/))Cl/sub 3/ and (M(L/sub 2//sup (1)/ or L/sub 2//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been isolated. In addition, macrocyclic complexes of Nd(III) andmore » Sm(III) with another series of tetraaza ligands, viz, 5,6,11,12-R/sub 4/-3,8-X/sub 2/-(12)-4,6,10,12-tetraene-1,4,7,10-N/sub 4/-(2,9-N/sub 2/) (R = CH/sub 3/, X = O (L/sub 3//sup (1)/); R = C/sub 6/H/sub 5/, X = O(L/sub 3//sup (2)/); R = CH/sub 3/, X = S(L/sub 4//sup (1)/); R = C/sub 6/H/sub 5/, X = S(L/sub 4//sup (2)/)), formulated as (M(L/sub 3//sup (1)/, L/sub 3//sup (2)/, L/sub 4//sup (1)/ or L/sub 4//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been prepared by template condensation of Nd(III) and Sm(III) complexes of diacetylbis(semicarbazonethiosemicarbazone) or benzilibis(semicarbazonethiosemicarbazone) with diacetyl or benzil. The complexes have been identified by elemental analysis, electrical conductance, spectral and thermal measurements.« less

Phase Separation Kinetics in Isopycnic Mixtures of H2O/CO2/Ethoxylated Alcohol Surfactants

NASA Technical Reports Server (NTRS)

Lesemann, Markus; Paulaitis, Michael E.; Kaler, Eric W.

1999-01-01

Ternary mixtures of H2O and CO2 with ethoxylated alcohol (C(sub i)E(sub j)) surfactants form three coexisting liquid phases at conditions where two of the phases have equal densities (isopycnic phases). Isopycnic phase behavior has been observed for mixtures containing C8E5, C10E6, and C12E6 surfactants, but not for those mixtures containing either C4E1 or C8E3 surfactants. Pressure-temperature (PT) projections for this three-phase equilibrium were determined for H2O/CO2/C8E5 and H2O/CO2/C10E6 mixtures at temperatures from approximately 25 to 33 C and pressures between 90 and 350 bar. Measurements of the microstructure in H2O/CO2/C12E6 mixtures as a function of temperature (25-31 C), pressure (63.1-90.7 bar), and CO2 composition (0-3.9 wt%) have also been carried out to show that while micellar structure remains essentially un-changed, critical concentration fluctuations increase as the phase boundary and plait point are approached. In this report, we present our first measurements of the kinetics of isopycnic phase separation for ternary mixtures of H2O/CO2/C8E5.

Conclusive evidence on the mechanism of the rhodium-mediated decyanative borylation.

PubMed

Esteruelas, Miguel A; Oliván, Montserrat; Vélez, Andrea

2015-09-30

The stoichiometric reactions proposed in the mechanism of the rhodium-mediated decyanative borylation have been performed and all relevant intermediates isolated and characterized including their X-ray structures. Complex RhCl{xant(P(i)Pr2)2} (1, xant(P(i)Pr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) reacts with bis(pinacolato)diboron (B2pin2), in benzene, to give the rhodium(III) derivative RhHCl(Bpin){xant(P(i)Pr2)2} (4) and PhBpin. The reaction involves the oxidative addition of B2pin2 to 1 to give RhCl(Bpin)2{xant(P(i)Pr2)2}, which eliminates ClBpin generating Rh(Bpin){xant(P(i)Pr2)2} (2). The reaction of the latter with the solvent yields PhBpin and the monohydride RhH{xant(P(i)Pr2)2} (6), which adds the eliminated ClBpin. Complex 4 and its catecholboryl counterpart RhHCl(Bcat){xant(P(i)Pr2)2} (7) have also been obtained by oxidative addition of HBR2 to 1. Complex 2 is the promoter of the decyanative borylation. Thus, benzonitrile and 4-(trifluoromethyl)benzonitrile insert into the Rh-B bond of 2 to form Rh{C(R-C6H4)═NBpin}{xant(P(i)Pr2)2} (R = H (8), p-CF3 (9)), which evolve into the aryl derivatives RhPh{xant(P(i)Pr2)2} (3) and Rh(p-CF3-C6H4){xant(P(i)Pr2)2} (10), as a result of the extrusion of CNBpin. The reactions of 3 and 10 with B2pin2 yield the arylBpin products and regenerate 2.

Influence of ball milling and annealing conditions on the properties of L10 FePt nanoparticles fabricated by a new green chemical synthesis method

NASA Astrophysics Data System (ADS)

Hu, X. C.; Capobianchi, A.; Gallagher, R.; Hadjipanayis, G. C.

2014-05-01

In this work, a new green chemical strategy for the synthesis of L10 FePt alloy nanoparticles is reported. The precursor is a polycrystalline molecular complex (Fe(H2O)6PtCl6), in which Fe and Pt atoms are arranged on alternating planes and milled with NaCl to form nanocrystals. Then the mixture was annealed under reducing atmosphere (5% H2 and 95% Ar) at temperatures varying from 350 °C to 500 °C for 2 h with a heating rate of 5 °C/min. After the reduction, the mixture was washed with water to remove the NaCl and L10 FePt nanoparticles were obtained. The X-Ray Diffraction pattern showed the presence of the characteristic peaks of the fct phase of FePt nanoparticles. Influence of precursor/NaCl ratio and ball milling time on particle size was investigated. Transmission electron microscopy images revealed that smaller precursor/NaCl ratio (10 mg/20 g) and longer milling time (15 h) lead to smaller particle size and narrower size distribution. Milling time does not influence the coercivity much but the decrease of the amount of precursor leads to a decrease of coercivity from 10.8 kOe to 4.8 kOe.

Synthesis of some 1,8-dioxoacridine carboxylic acid derivatives and the determination of their ionization constants in ethanol-water mixtures

NASA Astrophysics Data System (ADS)

Saygılı, Rukiye; Ulus, Ramazan; Yeşildağ, İbrahim; Kübra İnal, E.; Kaya, Muharrem; Murat Kalfa, O.; Zeybek, Bülent

2015-03-01

Four novel compounds of 1,8-dioxoacridine carboxylic acid derivatives (4-(3,3,6,6-tetramethyl-1,8-dioxo-9-phenyl-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(4-cyanophenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(2,4-dichlorophenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid) were prepared by the reaction of the 4-substitute benzaldehyde (hydrogen, hydroxyl, cyano, and 2,4-dichloro), 4-aminobenzoic acid, and 5,5-dimethylcyclohexane-1,3-dione in the presence of p-dodecylbenzenesulfonic acid. They were characterized by using FT-IR, 1H-NMR, 13C-NMR, GC-MS spectroscopic techniques. The stoichiometric ionization constants of these compounds were determined in ethanol-water mixtures of 50%, 60% and 70% ethanol (v/v) by potentiometric titration method and the ionization constants were calculated with three different ways. The effects of solvent composition and substituent groups on ionization constants of 1,8-dioxoacridine carboxylic acids were also discussed.

Reductive dehalogenation of endosulfan by cast iron: Kinetics, pathways and modeling.

PubMed

Lama, Yangdup; Sinha, Alok; Singh, Gurdeep; Masto, Reginald E

2016-05-01

Cast iron has been a material of choice for in-situ remediation of groundwater. In this study interaction of endosulfan with High Carbon Iron Filings (HCIF) was studied in batch reactors. Decline in total concentration (Ct) could be related to aqueous concentration (Ca) by equation dCt/dt = k1.M.Ca(n), where reaction rate constant (k1) and order (n) were found to be 1.246 × 10(-4) L g(-1) iron h(-1) and 1.47, respectively. Partitioning of endosulfan to HCIF could be explained by Freundlich isotherm. The process of simultaneous reductive dehalogenation and adsorption/desorption was successfully modelled. The reductive dehalogenation of endosulfan resulted in by-products identified as [(3a, alpha,7beta,7a alpha,8s)-4,5,6,7,8 Pentachloro 3a,4,7,7a-tetrahydro] (C9H3Cl5O3) and Benzofuran,4,5,7-trichloro-2,3-dihydro-2-methyl (C9H7Cl3O). Copyright © 2015 Elsevier Ltd. All rights reserved.

Development and Evaluation of Adeno-HTLV-III Hybrid Virus and Non- Cytopathic HTLV-III Mutant for Vaccine Use

DTIC Science & Technology

1988-10-28

I44r.0 + I I U.-4 Io 4- z+ (b I- 0 cj V I-SI: -4 I4 0)~ W4+ I ~ ’ IC14 e 9Q~ 4I cj-0 C:.L SI r. Cl I1C I0 -4 -4 I- .I -.t- 1 J.X- )0 1I 4 I I < < I w ...1-1 0 (3I I >+ ++ >> coZ mI WC ~ + U- H-i m ca IQg OI pI I4 cN.3 I "- .- 00I - I In :3 :3 w w 1 04l ci I I I I I ~ 4(~,-4~4.36 + a% 𔃺 001 to U 4-4...C) l~ u(V14:: - 4L + 4+ bC4 co4 ~0 M~ 40 -40~4. 4.4 bc I0 -l 110 C) 1 0 1 N, o 1) 41 -4 + cn, -H + N- to4 z:: Ia 41 w 1-1+ II,-HI r_ (cc ) (N -a* 1

Understanding the microcrystal tests of three related phenethylamines: the ortho-metallated (±)-amphetamine formed with gold(III) chloride, and the tetrachloridoaurate(III) salts of (+)-methamphetamine and (±)-ephedrine.

PubMed

Wood, Matthew R; Lalancette, Roger A

2013-04-01

The ortho-metallation product of the reaction of (±)-amphetamine with gold(III) chloride, [D,L-2-(2-aminopropyl)phenyl-κ(2)N,C(1)]dichloridogold(III), [Au(C9H12N)Cl2], and the two salts resulting from crystallization of (+)-methamphetamine with gold(III) chloride, D-methyl(1-phenylpropan-2-yl)azanium tetrachloridoaurate(III), (C10H16N)[AuCl4], and of (±)-ephedrine with gold(III) chloride, D,L-(1-hydroxy-1-phenylpropan-2-yl)(methyl)azanium tetrachloridoaurate(III), (C10H16NO)[AuCl4], have different structures. The first makes a bidentate complex directly with a dichloridogold(III) group, forming a six-membered ring structure; the second and third each form a salt with [AuCl4](-) (each has two formula units in the asymmetric unit). The organic components are all members of the same class of stimulants that are prevalent in illicit drug use. These structures are important contributions to the understanding of the microcrystal tests for these drugs that have been employed for well over 100 years.

Growth and optical, magnetic and transport properties of (C4H9NH3)2MCl4 organic-inorganic hybrid films (M = Cu, Sn)

NASA Astrophysics Data System (ADS)

Aruta, C.; Licci, F.; Zappettini, A.; Bolzoni, F.; Rastelli, F.; Ferro, P.; Besagni, T.

2005-10-01

Films of (C4H9NH3)2MCl4 (M=Cu and Sn) organic-inorganic hybrid perovskites have been deposited in-situ by a single-source thermal ablation technique on glassy, crystalline and polymeric substrates. Independently of the substrate, the films were well crystallized, c-axis oriented and with a narrow rocking curve of the (0010) reflection (full width at half maximum <1°). The (0 0 ℓ) reflections were consistent with those of the bulk orthorhombic phases and the “c” lattice parameters were 30.85±0.05 and 32.35±0.05 Å, for the Cu- and the Sn-compound, respectively. (C4H9NH3)2CuCl4 films had an optical absorption peak at 375 nm at room temperature. From the magnetic point of view they act as layered nanocomposites with a dominant ferromagnetic component localized in planes (2D magnetism). Tc was 7.3±0.1 K and a moderate easy-plane anisotropy was observed. The photoluminescence spectra of typical (C4H9NH3)2SnCl4 films at 12 K had a broad yellow band, which did not correspond to any significant peak in the absorption spectrum. The films were semiconducting down to 250 K or, in the case of the best samples, down to 200 K and became insulating at lower temperature. The resistivity of the best films was (5±1) 104 Ω cm at 300 K, and the energy gap was 1.11 eV.

Novel passivation dielectrics-The boron- or phosphorus-doped hydrogenated amorphous silicon carbide films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C.Y.; Fang, Y.K.; Huang, C.F.

1985-02-01

Hydrogenated amorphous silicon carbide (a-SiC:H) thin films were prepared and studied in a radiofrequency glowdischarge system, using a gas mixture of SiH/sub 4/ and one of the following carbon sources: methane (CH/sub 4/), benzene (C/sub 6/H/sub 6/), toluene (C/sub 7/H/sub 8/), sigma-xylene (C/sub 8/H/sub 10/), trichloroethane (C/sub 2/H/sub 3/Cl/sub 3/), trichloroethylene (C/sub 2/HCl/sub 3/), or carbon tetrachloride (CCl/sub 4/). The effect of doping phosphorus and boron into those a-SiC:H films on chemical etching rate, electrica dc resistivity, breakdown strength, and optical refractive index have been systematically investigated. Their chemical etching properties were examined by immersing in 49% HF, buffered HF,more » 180/sup 0/C H/sub 3/PO/sub 4/ solutions, or in CF/sub 4/ + O/sub 2/ plasma. It was found that the boron-doped a-SiC:H film possesses five times slower etching rate than the undoped one, while phosphorus-doped a-SiC:H film shows about three times slower. Among those a-SiC:H films, the one obtained from a mixture of SiH/sub 4/ and benzene shows the best etch-resistant property, while the ones obtained from a mixture of SiH/sub 4/ and chlorine containing carbon sources (e.g., trichloroethylene, trichloroethane, or carbon tetrachloride) shows that they are poor in etching resistance (i.e., the etching rate is higher). By measuring dc resistivity, dielectric breakdown strength, and effective refractive index, it was found that boron- or phosphorus-doped a-SiC:H films exhibit much higher dielectric strength and resistivity, but lower etching rate, presumably because of higher density.« less

Ring Opening Polymerization and Copolymerization of Cyclic Esters Catalyzed by Group 2 Metal Complexes Supported by Functionalized P-N Ligands.

PubMed

Harinath, Adimulam; Bhattacharjee, Jayeeta; Sarkar, Alok; Nayek, Hari Pada; Panda, Tarun K

2018-03-05

We report the preparation of alkali and alkaline earth (Ae) metal complexes supported by 2-picolylamino-diphenylphosphane chalcogenide [(Ph 2 P(=E)NHCH 2 (C 5 H 4 N)] [E = S (1-H); Se (2-H)] ligands. The treatment of the protic ligand, 1-H or 2-H, with alkali metal hexamethyldisilazides at room temperature afforded the corresponding alkali metal salts [M(THF) 2 (Ph 2 P(=E)NCH 2 (C 5 H 4 N)] [M = Li, E = S (3a), Se (3b)] and [{M(THF) n (Ph 2 P(=E)NCH 2 (C 5 H 4 N)} 2 ] [M = Na, E = S (4a), Se (4b); M = K, E = Se (5b)] in good yield. The homoleptic Ae metal complexes [κ 2 -(Ph 2 P(=Se)NCH 2 (C 5 H 4 N)Mg(THF)] (6b) and [κ 3 -{(Ph 2 P(=Se)NCH 2 (C 5 H 4 N)} 2 M(THF) n ] (M = Ca (7b), Sr (8b), Ba (9b)] were synthesized by the one-pot reaction of 2-H with [KN(SiMe 3 ) 2 ] and MI 2 in a 2:2:1 molar ratio at room temperature. The molecular structures of the protic-ligands 1-H and 2-H, as well as complexes 3a,b-5a,b and 6b-9b were established using single-crystal X-ray analysis. The Ae metal complexes 6b-9b were tested for ring-opening polymerization (ROP) of racemic lactide ( rac-LA) and copolymerization of rac-LA and ε-caprolactone (ε-CL) at room temperature. In the ROP of rac-LA, the calcium complex 7b exhibited high isoselectivity, with P i = 0.89, whereas both the barium and strontium complexes showed lower isoselectivity with P i = 0.78-0.62. In the copolymerization of rac-LA and ε-CL, both barium and strontium complexes proved to be efficient precatalysts for the formation of the block copolymer rac-LA-CL, but the reactivity of 9b was found to be better than that of 8b. All the polymers were fully characterized using differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography analyses. Kinetic studies on the ROP reaction of LA confirmed that the rate of polymerization followed the order Ba ≫ Sr ≈ Ca.

The Synthesis of Potential Antiparasitic Drugs

DTIC Science & Technology

1990-05-01

CF3 24. R - 4-Cl,3-CF3 Scheme 1, Continued 38 Contract No. DAMD17-88-C-8106 O >—-(.CH2)5-B Br(CH2) sBr 25 26. P. • 4-C1 27. R a 2-CF3 28. R...methyl-4-phthalimidobuty- lamino)quinoLine (63) A stirred mixture of 51 (3.27 g, 0.009 mol) and 4-bromo-l-phthalimido- pentane ( BPP ) (5.23 g...0.018 mol) was heated at 120-125°C while Et.N (3 ml) was slowly added during 30 min. After 3.5h at 120-125°C, more BPP (3.42 g, 0.012 mol) and Et^N (2

Solubility of alkali metal halides in the ionic liquid [C4C1im][OTf].

PubMed

Kuzmina, O; Bordes, E; Schmauck, J; Hunt, P A; Hallett, J P; Welton, T

2016-06-28

The solubilities of the metal halides LiF, LiCl, LiBr, LiI, NaF, NaCl, NaBr, NaI, KF, KCl, KBr, KI, RbCl, CsCl, CsI, were measured at temperatures ranging from 298.15 to 378.15 K in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([C4C1im][OTf]). Li(+), Na(+) and K(+) salts with anions matching the ionic liquid have also been investigated to determine how well these cations dissolve in [C4C1im][OTf]. This study compares the influence of metal cation and halide anion on the solubility of salts within this ionic liquid. The highest solubility found was for iodide salts, and the lowest solubility for the three fluoride salts. There is no outstanding difference in the solubility of salts with matching anions in comparison to halide salts. The experimental data were correlated employing several phase equilibria models, including ideal mixtures, van't Hoff, the λh (Buchowski) equation, the modified Apelblat equation, and the non-random two-liquid model (NRTL). It was found that the van't Hoff model gave the best correlation results. On the basis of the experimental data the thermodynamic dissolution parameters (ΔH, ΔS, and ΔG) were determined for the studied systems together with computed gas phase metathesis parameters. Dissolution depends on the energy difference between enthalpies of fusion and dissolution of the solute salt. This demonstrates that overcoming the lattice energy of the solid matrix is the key to the solubility of inorganic salts in ionic liquids.

On chemical inhibition of shock wave ignition of hydrogen-oxygen mixtures

NASA Astrophysics Data System (ADS)

Drakon, A. V.; Eremin, A. V.; Mikheyeva, E. Yu

2018-01-01

In this work an influence of the wide range of various inhibitors, namely CCl4, CF3H, C2F4Br2, (CH3O)3P, CF3I and C3F7I on shock-induced ignition of hydrogen was experimentally investigated. Observed temperature dependencies of induction times indicates that CF3H and (CH3O)3P do not show noticeable inhibiting activity at given conditions, while the effectiveness of halogen-containing specie dramatically increases in a row Cl → Br → I. It is shown that the most effective inhibitors of ignition of hydrogen-oxygen mixtures are iodinated hydrocarbons CF3I and C3F7I.

A study of nonflammable ArCO 2-hydrocarbon gas mixtures for limited streamer tubes

NASA Astrophysics Data System (ADS)

Cartwright, S.; Schneekloth, U.; Alpat, B.; Artemi, C.; Battiston, R.; Bilei, G.; Italiani, M.; Pauluzzi, M.; Servoli, L.; Messner, R.; Wyss, J.; Zdarko, R.; Johnson, J.

1989-04-01

The gas mixtures generally used until now in limited streamer tube detectors (Ar+C 4H 10 or Ar+CO 2+C 5H 12) are very flammable when leaked into air. The safety issues are therefore very relevant for large-volume underground experiments. We have found a set of completely safe (i.e. nonflammable) ternary mixtures of the kind Ar + hydrocarbon + CO 2 containing less than ˜ 5% of Ar and less than ˜ 10% of hydrocarbon. We tested C 4H 10, C 5H 12 and C 6H 14 as quenching agents. The main characteristics of the various mixtures have been measured: singles (untriggered) counting rate versus high voltage and with different dead times, and average charge. The stability of these mixtures is good, and their spurious streamer activity is compared with the standard binary or ternary mixture. We studied in particular the combination Ar(2.5%) + C 4H 10(9.5%) + CO 2(88%). All the data suggest that this or a similar gas mixture can successfully replace standard flammable mixtures both in tracking devices and hadron calorimeters.

Design and syntheses of hybrid metal-organic materials based on K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] metallotectons

NASA Astrophysics Data System (ADS)

Sun, Yayong; Zong, Yingxia; Ma, Haoran; Zhang, Ao; Liu, Kang; Wang, Debao; Wang, Wenqiang; Wang, Lei

2016-05-01

By using K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] (C2O42-=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C2O4)2(H2O)2}2]·(H-L1)2·H2O 1, [Fe(C2O4)Cl2]·(H2-L2)0.5·(L2)0.5·H2O 2, [{Fe(C2O4)1.5Cl2}2]·(H-L3)43, [Fe2(C2O4)Cl8]·(H2-L4)2·2H2O 4, K[Al(C2O4)3]·(H2-L5)·2H2O 5, K[Al(C2O4)3]·(H-L6)2·2H2O 6, K[Cr(C2O4)3]·2H2O 7, Na[Fe(C2O4)3]·(H-L6)2·2H2O 8 (with L1=4-dimethylaminopyridine, L2=2,3,5,6-tetramethylpyrazine, L3=2-aminobenzimidazole, L4=1,4-bis-(1H-imidazol-1-yl)benzene, L5=1,4-bis((2-methylimidazol-1-yl)methyl)benzene, L6=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C2O4)2(H2O)2]- unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C2O4)Cl2]- anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe2(C2O4)3Cl4]4- unit. Compound 4 features distinct [Fe2(C2O4)Cl8]4- units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C2O4)3]3- units and K+ cations. The 1D chains are further extended into 3D antionic H-bonded framework through O-H···O H-bonds. Compounds 6-8 show 2D [KAl(C2O4)3]2- layer, [KCr(C2O4)3]2- layer and [NaFe(C2O4)3]2- layer, respectively.

Identification of tetrapeptides from a mixture based positional scanning library that can restore nM full agonist function of the L106P, I69T, I102S, A219V, C271Y, and C271R human melanocortin-4 polymorphic receptors (hMC4Rs).

PubMed

Haslach, Erica M; Huang, Huisuo; Dirain, Marvin; Debevec, Ginamarie; Geer, Phaedra; Santos, Radleigh G; Giulianotti, Marc A; Pinilla, Clemencia; Appel, Jon R; Doering, Skye R; Walters, Michael A; Houghten, Richard A; Haskell-Luevano, Carrie

2014-06-12

Human obesity has been linked to genetic factors and single nucleotide polymorphisms (SNPs). Melanocortin-4 receptor (MC4R) SNPs have been associated with up to 6% frequency in morbidly obese children and adults. A potential therapy for individuals possessing such genetic modifications is the identification of molecules that can restore proper receptor signaling and function. These compounds could serve as personalized medications improving quality of life issues as well as alleviating diseases symptoms associated with obesity including type 2 diabetes. Several hMC4 SNP receptors have been pharmacologically characterized in vitro to have a decreased, or a lack of response, to endogenous agonists such as α-, β-, and γ2-melanocyte stimulating hormones (MSH) and adrenocorticotropin hormone (ACTH). Herein we report the use of a mixture based positional scanning combinatorial tetrapeptide library to discover molecules with nM full agonist potency and efficacy to the L106P, I69T, I102S, A219V, C271Y, and C271R hMC4Rs. The most potent compounds at all these hMC4R SNPs include Ac-His-(pI)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Arg-(pI)Phe-NH2, and Ac-Arg-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, revealing new ligand pharmacophore models for melanocortin receptor drug design strategies.

Identification of Tetrapeptides from a Mixture Based Positional Scanning Library That Can Restore nM Full Agonist Function of the L106P, I69T, I102S, A219V, C271Y, and C271R Human Melanocortin-4 Polymorphic Receptors (hMC4Rs)

PubMed Central

2015-01-01

Human obesity has been linked to genetic factors and single nucleotide polymorphisms (SNPs). Melanocortin-4 receptor (MC4R) SNPs have been associated with up to 6% frequency in morbidly obese children and adults. A potential therapy for individuals possessing such genetic modifications is the identification of molecules that can restore proper receptor signaling and function. These compounds could serve as personalized medications improving quality of life issues as well as alleviating diseases symptoms associated with obesity including type 2 diabetes. Several hMC4 SNP receptors have been pharmacologically characterized in vitro to have a decreased, or a lack of response, to endogenous agonists such as α-, β-, and γ2-melanocyte stimulating hormones (MSH) and adrenocorticotropin hormone (ACTH). Herein we report the use of a mixture based positional scanning combinatorial tetrapeptide library to discover molecules with nM full agonist potency and efficacy to the L106P, I69T, I102S, A219V, C271Y, and C271R hMC4Rs. The most potent compounds at all these hMC4R SNPs include Ac-His-(pI)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Arg-(pI)Phe-NH2, and Ac-Arg-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, revealing new ligand pharmacophore models for melanocortin receptor drug design strategies. PMID:24517312

Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

NASA Astrophysics Data System (ADS)

Gowda, B. Thimme; Shetty, Mahesha; Jayalakshmi, K. L.

2005-02-01

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN-H, absorb in the range 3285 - 3199 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm-1 and 1177 - 1148 cm-1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm-1 and 1304 - 1168 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X'C6H4SO2- and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X'C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

Effects of rare earth element lanthanum on rumen methane and volatile fatty acid production and microbial flora in vitro.

PubMed

Zhang, T T; Zhao, G Y; Zheng, W S; Niu, W J; Wei, C; Lin, S X

2015-06-01

The objectives of the trial were to study the effects of rare earth element (REE) lanthanum (La) on the in vitro rumen methane (CH4 ) and volatile fatty acid (VFA) production and the microbial flora of feeds. Four feed mixtures with different levels of neutral detergent fibre (NDF), that is 20.0% (I), 31.0% (II), 41.9% (III) and 52.7% (IV), were formulated as substrates. Five levels of LaCl3 , that is 0, 0.4, 0.6, 0.8 and 1.0 mmol/kg dry matter (DM), were added to the feed mixtures, respectively, as experimental treatments in a two-factor 5 × 4 randomized design. The in vitro incubation lasted for 24 h. The results showed that supplementing LaCl3 increased the total gas (p < 0.001) production and tended to increase the total VFA production (p = 0.072) and decreased the CH4 production (p = 0.001) and the ratios of acetate/propionate (p = 0.019) and CH4 /total VFA (p < 0.001). Interactions between LaCl3 and NDF were significant in total gas production (p = 0.030) and tended to be significant in CH4 production (p = 0.071). Supplementing LaCl3 at the level of 0.8 mmol/g DM decreased the relative abundance of methanogens and protozoa in the total bacterial 16S rDNA analysed using the real-time PCR (p < 0.0001), increased F. succinogenes (p = 0.0003) and decreased R. flavefaciens (p < 0.0001) whereas did not affect R. albus and anaerobic fungi (p > 0.05). It was concluded that LaCl3 decreased the CH4 production without negatively affecting feed digestion through manipulating rumen microbial flora when feed mixtures with different levels of NDF were used as substrates. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis.

PubMed

Beuchat, Larry R; Pettigrew, Charles A; Tremblay, Mario E; Roselle, Brian J; Scouten, Alan J

2004-08-01

Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 microg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 microg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 microg/ml), acidified (pH 3.4) ClO2 (85 microg/ml), and a mixture of ClO2 (85 microg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 microg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2.

Shock-tube studies of silicon-compound vapors

NASA Technical Reports Server (NTRS)

Park, C.; Fujiwara, T.

1977-01-01

Test gas mixtures containing SiO, SiO2, Si2, and SiH were produced in a shock tube by processing shock waves through a mixture of SiCl4 + N2O + Ar, SiH4 + Ar, or SiH4 + O2 + Ar. Absorption spectra of the test gases were studied photographically in the reflected shock region using a xenon flash lamp as the light source in the range of wavelengths between 250 and 600 nm. SiO was found to be a dominant species in the vapors produced by the SiCl4 + N2O and SiH4 + O2 mixtures. Spontaneous combustion was observed in the SiH4 + O2 + Ar mixture prior to the shock arrival, and the resulting solid SiO2 particles evaporated behind the shock wave. Spectral absorption characteristics of SiO, SiO2, Si2, and SiH were determined by studying the test gases.

Perchlorate mixed-ligand copper(II) complexes of beta-diketone and ethylene diamine derivatives: thermal, spectroscopic and biochemical studies.

PubMed

El-Ayaan, Usama; El-Metwally, Nashwa M; Youssef, Magdy M; El Bialy, Serry A A

2007-12-31

The present work carried out a study on perchlorate mixed-ligand copper(II) complexes which have been synthesized from ethylenediamine derivatives (3a-c) and beta-diketones. These complexes, namely [Cu(DA-Cl)(acac)H(2)O]ClO(4)4, [Cu(DA-Cl)(bzac)H(2)O]H(2)O.ClO(4)5, [Cu(DA-OMe)(acac)H(2)O]ClO(4)6, [Cu(DA-OMe)(bzac)H(2)O]ClO(4)7, [Cu(DA-H)(acac)H(2)O]2H(2)O.ClO(4)8 and [Cu(DA-H)(bzac)H(2)O]ClO(4)9 (where acac, acetylacetonate and bzac, benzoylacetonate) were characterized by elemental analysis, spectral (IR and UV-vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all complexes are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters (E, A, DeltaH, DeltaS and DeltaG) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. The biochemical studies showed that, the diamines 3a-c have powerful effects on degradation of DNA and protein. The antibacterial screening demonstrated that, the diamine (DA-Cl), 3b has the maximum and broad activities against Gram +ve and Gram -ve bacterial strains.

Synthesis, characterisation and computational studies on a novel one-dimensional arrangement of Schiff-base Mn3 single-molecule magnet.

PubMed

Lin, Po-Heng; Gorelsky, Serge; Savard, Didier; Burchell, Tara J; Wernsdorfer, Wolfgang; Clérac, Rodolphe; Murugesu, Muralee

2010-09-07

The syntheses, structures and magnetic properties are reported for three new manganese complexes containing the Schiff-base ((2-hydroxy-3-methoxyphenyl)methylene)isonicotinohydrazine (H(2)hmi) ligand. Complex [Mn(II)(H(2)hmi)(2)(MeOH)(2)Cl(2)] (1) was obtained from the reaction of H(2)hmi with MnCl(2) in a MeOH-MeCN mixture. Addition of triethylamine to the previous reaction mixture followed by diethyl ether diffusion yielded a dinuclear manganese [Mn(III)(2)(hmi)(2)(OMe)(2)](infinity).2MeCN.2OEt(2) (2) compound. Upon increasing the MnCl(2)/H(2)hmi ratio, the mixed valence complex [Mn(III)(2)Mn(II)(hmi)(2)(OMe)(2)Cl(2)](infinity).MeOH (3) was obtained. Dc and ac magnetic measurements were carried out on all three samples. The ac susceptibility and field dependence of the magnetisation measurements confirmed that complex 3 exhibits a single-molecule magnet behaviour with an effective energy barrier of 8.1 K and an Arrhenius pre-exponential factor of 3 x 10(-9) s.

Crystal structure of bis-[μ-(4-meth-oxy-phen-yl)methane-thiol-ato-κ(2) S:S]bis-[chlorido-(η(6)-1-isopropyl-4-methyl-benzene)-ruthenium(II)] chloro-form disolvate.

PubMed

Stíbal, David; Süss-Fink, Georg; Therrien, Bruno

2015-10-01

The mol-ecular structure of the title complex, [Ru2(C8H9OS)2Cl2(C10H14)2]·2CHCl3 or (p-MeC6H4Pr (i) )2Ru2(SCH2-p-C6H5-OCH3)2Cl2·2CHCl3, shows inversion symmetry. The two symmetry-related Ru(II) atoms are bridged by two 4-meth-oxy-α-toluene-thiol-ato [(4-meth-oxy-phen-yl)methane-thiol-ato] units. One chlorido ligand and the p-cymene ligand complete the typical piano-stool coordination environment of the Ru(II) atom. In the crystal, the CH moiety of the chloro-form mol-ecule inter-acts with the chlorido ligand of the dinuclear complex, while one Cl atom of the solvent inter-acts more weakly with the methyl group of the bridging 4-meth-oxy-α-toluene-thiol-ato unit. This assembly leads to the formation of supra-molecular chains extending parallel to [021].

The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts.

PubMed

Raatikainen, Kari; Cametti, Massimo; Rissanen, Kari

2010-01-15

THE SERIES OF HALOANILINIUM AND HALOPYRIDINIUM SALTS: 4-IPhNH₃Cl (1), 4-IPhNH₃Br (5), 4-IPhNH₃H₂PO₄ (6), 4-ClPhNH₃H₂PO₄ (8), 3-IPyBnCl (9), 3-IPyHCl (10) and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13), where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH₃Cl (2, CCDC ref. code TAWRAL), 4-ClPhNH₃Cl (3, CURGOL), 4-FPhNH₃Cl (4, ANLCLA), 4-BrPhNH₃H₂PO₄, (7, UGISEI), 3-BrPyHCl, (11, CIHBAX) and 3-ClPyHCl, (12, VOQMUJ) from Cambridge Structural Database for sake of comparison. Based on the X-ray data it was possible to highlight the balance between non-covalent forces acting in these systems, where the relative strength of the halogen bonding C-X...A⁻ (X = I, Br or Cl) and the ratio between the halogen and hydrogen bonds [C-X...A⁻ : D-H...A⁻] varied across the series.

Brines formed by multi-salt deliquescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carroll, S; Rard, J; Alai, M

2005-11-04

The FY05 Waste Package Environment testing program at Lawrence Livermore National Laboratory focused on determining the temperature, relative humidity, and solution compositions of brines formed due to the deliquescence of NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures. Understanding the physical and chemical behavior of these brines is important because they define conditions under which brines may react with waste canister surfaces. Boiling point experiments show that NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures form brines that transform to hydrous melts that do not truly 'dry out' until temperatures exceed 300 and 400more » C, respectively. Thus a conducting solution is present for these salt assemblages over the thermal history of the repository. The corresponding brines form at lower relative humidity at higher temperatures. The NaCl-KNO{sub 3}-NaNO{sub 3} salt mixture has a mutual deliquescence relative humidity (MDRH) of 25.9% at 120 C and 10.8% at 180 C. Similarly, the KNO{sub 3}-NaNO{sub 3} salt mixture has MDRH of 26.4% at 120 C and 20.0% at 150 C. The KNO{sub 3}-NaNO{sub 3} salt mixture salts also absorb some water (but do not appear to deliquesce) at 180 C and thus may also contribute to the transfer of electrons at interface between dust and the waste package surface. There is no experimental evidence to suggest that these brines will degas and form less deliquescent salt assemblages. Ammonium present in atmospheric and tunnel dust (as the chloride, nitrate, or sulfate) will readily decompose in the initial heating phase of the repository, and will affect subsequent behavior of the remaining salt mixture only through the removal of a stoichiometric equivalent of one or more anions. Although K-Na-NO{sub 3}-Cl brines form at high temperature and low relative humidity, these brines are dominated by nitrate, which is known to inhibit corrosion at lower temperature. Nitrate to chloride ratios of the NaCl-KNO{sub 3}-NaNO{sub 3} salt mixture are about NO{sub 3}:Cl = 19:1. The role of nitrate on corrosion at higher temperatures is addressed in a companion report (Dixit et al., 2005).« less

The stability of Cl-CO3-scapolite relative to plagioclase + CaCO3 + CaSO4 in the presence of NaCl brines as a function of P-T-XNaCl

NASA Astrophysics Data System (ADS)

Harlov, D. E.; Budzyn, B.

2008-12-01

Cl-CO3-scapolite [(Na,Ca)4[Al3 (Al,Si) 3 Si3 O24](Cl, CO3 , SO4 )] occurs as a common partial to total alteration of plagioclase in deep-crustal xenoliths, skarns, marbles, gabbros, metabasites, calc-silicate gneisses, as well as in quartzofeldspathic granulite-facies rocks in general (Moecher and Essene, 1990, J Petrol 31, 997). Alteration of plagioclase to Cl-CO3-scapolite is presumed due to metasomatism by CO2-NaCl-H2O fluids (Satish-Kumar and Santosh, 1998, Geol Mag 135, 27). Previous experimental work on CO3-scapolite has focused on reversing the equilibrium 3 CaAl2 Si2 O8 + CaCO3 = Ca4 Al6 Si6 O24 CO3 in either pure CO2 (Goldschmidt and Newton, 1977, Am Mineral 62, 1063) or in CO2-H2O (Huckenholz and Seiberl, 1989 Abs IGC 28, 2.79). These experiments have determined that the anorthite- calcite-scapolite equilibrium is nearly pressure-invariant in P-T space (200 to 1500 MPa) occurring at approximately 790 to 820 °C (Huckenholz and Seiberl, 1989). In this study, a series of experiments, involving the equilibrium 3 Plagioclase(An60) + 0.5 CaCO3 + 0.5 CaSO4 = [(Na,Ca)4[Al3 (Al,Si)3 Si3 O24](Cl, CO3, SO4 )] plus an NaCl brine (10/90, 20/80, 30/70, and 50/50 molar NaCl/H2O) have been done at 500, 1000, and 1500 MPa and 600 to 900 °C. Natural plagioclase and scapolite, along with synthetic calcite and anhydrite, were lightly ground together in equi-molar amounts in ethanol. The mineral mix (10 mg) + NaCl brine (5 mg), or pure H2O (1.5 mg), were loaded into 3 mm diameter/1.3 mm long Pt capsules which were arc-welded shut, folded, and placed horizontally in a CaF2 setup (with graphite oven), such that the thermocouple tip touched the Pt capsule, or placed in a hydrothermal autoclave (600 and 700 °C; 500 MPa) with an internal thermocouple. A series of duplicate experiments for the same mineral mix, at the same P-T conditions, were done utilizing pure H2O as the flux. The H2O-only experiments duplicated the P-T reversals of Huckenholz and Seiberl (1989). In contrast, the NaCl/H2 O experiments indicate that the stability field of Cl-CO3-scapolite (SiO2 =52.1, Al2O3=24.9, CaO=11.9, Na2O=7.60, Cl=1.86, CO3=2.00, SO4=0.45), relative to plagioclase, greatly expands in the presence of NaCl brines at NaCl concentrations above 10 percent NaCl such that Cl-CO2-scapolite is stable over 600 to 900 °C and 500 to 1500 MPa. This result further strengthens the proposition that NaCl brines, coupled with CO2-bearing fluids, can be and probably are involved during high-grade scapolitization of plagioclase-bearing rocks in the mid to lower crust and upper mantle.

Dense Energetic Compounds of C, H, N, and O Atoms. III. 5-(4-Nitro-(1,2, 5)oxadiazolyl)-5H-(1,2,3)triazolo(4,5-c)(1,2,5)oxadiazole

DTIC Science & Technology

1993-07-21

1,2,5)oxadiazolyl]-5H- [1,2,3]triazolo[4,5-c] [1,2,5]oxadiazole 1. The azide 5 was con- verted to a phosphinimine 9 in a reaction with triphenylphosphine ...and led instead to an intractable mixture in which neither a primary amine nor triphenylphosphine oxide were de- tected. ACKNOWLEDGEMENTS Financial...coi-responding amine 13 was obtained from the azide 5 by reduction with stannous chloride and was oxidized by ammonium persulfate to 5-[4- nitro

Bovine serum albumin partitioning in an aqueous two-phase system: effect of pH and sodium chloride concentration.

PubMed

Gündüz, U; Korkmaz, K

2000-06-23

The partitioning of bovine serum albumin (BSA) in a polyethylene glycol 3350 (8% w/w)-dextran 37 500 (6% w/w)-0.05 M phosphate aqueous two-phase was investigated at different pHs, at varying concentrations of sodium chloride at 20 degrees C. The effect of NaCl concentration on the partition coefficient of BSA was studied for the PEG-dx systems with initial pH values of 4.2, 5.0, 7.0, 9.0, and 9.8. The NaCl concentrations in the phase systems with constant pH value were 0.06, 0.1, 0.2, 0.3, and 0.34 M. It was observed that the BSA partition coefficient decreased at concentrations smaller than 0.2 M NaCl and increased at concentrations greater than 0.2 M NaCl for all systems with initial pHs of 4.2, 5.0, 7.0, 9.0, and 9.8. It was also seen that the partition coefficient of BSA decreased as the pH of the aqueous two-phase systems increased at any NaCl salt concentration studied.

Equatorially connected diruthenium(II,III) units toward paramagnetic supramolecular structures with singular magnetic properties.

PubMed

Barral, M Carmen; Gallo, Teresa; Herrero, Santiago; Jiménez-Aparicio, Reyes; Torres, M Rosario; Urbanos, Francisco A

2006-05-01

The reaction of Ru2Cl(O2CMe)(DPhF)3 (DPhF = N,N'-diphenylformamidinate) with mono- and polycarboxylic acids gives a clean substitution of the acetate ligand, leading to the formation of complexes Ru2Cl(O2CC6H5)(DPhF)3 (1), Ru2Cl(O2CC6H4-p-CN)(DPhF)3 (2), [Ru2Cl(DPhF)3(H2O)]2(O2C)2 (3), [Ru2Cl(DPhF)3]2[C6H4-p-(CO2)2] (4), and [Ru2Cl(DPhF)3]3[C6H3-1,3,5-(CO2)3] (5). The preparation of [Ru2(NCS)(DPhF)3]3[C6H3-1,3,5-(CO2)3] (6) and {[Ru2(DPhF)3(H2O)]3[C6H3-1,3,5-(CO2)3]}(SO3CF3)3 (7) from 5 is also described. All complexes are characterized by elemental analysis, IR and electronic spectroscopy, mass spectrometry, cyclic voltammetry, and variable-temperature magnetic measurements. The crystal structure determinations of complexes 2.0.5THF and 3.THF.4H2O (THF = tetrahydrofuran) are reported. The reactions carried out demonstrate the high chemical stability of the fragment [Ru2(DPhF)3]2+, which is preserved in all tested experimental conditions. The stability of this fragment is also corroborated by the mass spectra. Electrochemical measurements reveal in all complexes one redox process due to the equilibrium Ru2(5+) <--> Ru2(6+). In the polynuclear complex 7, some additional oxidation processes are also observed that have been ascribed to the presence of two types of dimetallic units rather than two consecutive reversible oxidations. The magnetic behavior toward temperature for complexes 1-7 from 300 to 2 K is analyzed. Complexes 1-7 show low values of antiferromagnetic coupling in accordance with the molecular nature in 1 and 2 and the absence of important antiferromagnetic interaction through the carboxylate bridging ligands in 3-7, respectively. In addition, the magnetic properties of complex 7 do not correspond to any magnetic behavior described for diruthenium(II,III) complexes. The experimental data of compound 7 are simulated considering a physical mixture of S = 1/2 and 3/2 spin states. This magnetic study demonstrates the high sensitivity of the electronic configuration of the unit [Ru2(DPhF)3]2+ to small changes in the nature of the axial ligands. Finally, the energy gap between the pi and delta orbitals in these types of compounds allows the tentative assignment of the transition pi --> delta.

Magnetic properties of diruthenium(II,III) carboxylate compounds. Crystal structures of Ru2Cl(mu-O2CCH=CHCH=CHMe)4 and Ru2Cl(mu-O2CCH2OMe)4.

PubMed

Barral, M C; Jiménez-Aparicio, R; Pérez-Quintanilla, D; Priego, J L; Royer, E C; Torres, M R; Urbanos, F A

2000-01-10

The reaction of Ru2Cl(mu-O2CMe)4 with 2,4-hexadienoic and 2-methoxyacetic acids affords the compounds Ru2Cl(mu-O2CR)4 [R = CH=CHCH=CHCH3 (1), CH2OMe (2)]. The structures of both complexes have been determined by X-ray crystallography. 1 crystallizes in the triclinic space group P-1 with a = 9.264(1) A, b = 12.661(8) A, c = 12.839(5) A, alpha = 106.09(3) degrees, beta = 77.89(2) degrees, gamma = 97.73(3) degrees, and Z = 2. 2 crystallizes in the nonstandard monoclinic space group P2(1)/c with a = 12.132(4) A, b = 11.570(2) A, c = 13.674(2) A, beta = 91.18(2) degrees, and Z = 4. Complexes 1 and 2 show [Ru2(mu-O2CR)4]+ units linked by chloride ions, giving zigzag chains with Ru-Cl-Ru angles of 119.43(4) degrees and 110.11(7) degrees, respectively. The Ru-Ru bond distances are 2.2857(9) A (1) and 2.290(1) A (2). A magnetic study, in the 2-300 K temperature range, of the new compounds and the previously described Ru2Cl(mu-O2CR)4 [R = CHMe2 (3), CMe3 (4), C4H4N (5)] is described. The polymeric complexes 1 and 2 and the nonpolymeric 3-5 show a large zero-field splitting which varies from 53.9 to 68.1 cm-1. These complexes also show a weak, but not negligible, through-space intermolecular antiferromagnetic coupling not observed in the previous magnetic studies carried out on these types of compounds.

Infrared absorption of CH3OSO and CD3OSO radicals produced upon photolysis of CH3OS(O)Cl and CD3OS(O)Cl in p-H2 matrices.

PubMed

Lee, Yu-Fang; Kong, Lin-Jun; Lee, Yuan-Pern

2012-03-28

Irradiation at 239 ± 20 nm of a p-H(2) matrix containing methoxysulfinyl chloride, CH(3)OS(O)Cl, at 3.2 K with filtered light from a medium-pressure mercury lamp produced infrared (IR) absorption lines at 3028.4 (attributable to ν(1), CH(2) antisymmetric stretching), 2999.5 (ν(2), CH(3) antisymmetric stretching), 2950.4 (ν(3), CH(3) symmetric stretching), 1465.2 (ν(4), CH(2) scissoring), 1452.0 (ν(5), CH(3) deformation), 1417.8 (ν(6), CH(3) umbrella), 1165.2 (ν(7), CH(3) wagging), 1152.1 (ν(8), S=O stretching mixed with CH(3) rocking), 1147.8 (ν(9), S=O stretching mixed with CH(3) wagging), 989.7 (ν(10), C-O stretching), and 714.5 cm(-1) (ν(11), S-O stretching) modes of syn-CH(3)OSO. When CD(3)OS(O)Cl in a p-H(2) matrix was used, lines at 2275.9 (ν(1)), 2251.9 (ν(2)), 2083.3 (ν(3)), 1070.3 (ν(4)), 1056.0 (ν(5)), 1085.5 (ν(6)), 1159.7 (ν(7)), 920.1 (ν(8)), 889.0 (ν(9)), 976.9 (ν(10)), and 688.9 (ν(11)) cm(-1) appeared and are assigned to syn-CD(3)OSO; the mode numbers correspond to those used for syn-CH(3)OSO. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers, infrared intensities, and deuterium isotopic shifts with those predicted with the B3P86∕aug-cc-pVTZ method. Our results extend the previously reported four transient IR absorption bands of gaseous syn-CH(3)OSO near 2991, 2956, 1152, and 994 cm(-1) to 11 lines, including those associated with C-O, O-S, and S=O stretching modes. Vibrational wavenumbers of syn-CD(3)OSO are new. These results demonstrate the advantage of a diminished cage effect of solid p-H(2) such that the Cl atom, produced via UV photodissociation of CH(3)OS(O)Cl in situ, might escape from the original cage to yield isolated CH(3)OSO radicals.

Cloud Climatology Derived from the AFGWC (Air Force Global Weather Central) 3D-Nephanalysis for January and July 1979.

DTIC Science & Technology

1987-01-15

January 1979. 29 Coo E 1979 2~0 C NHOOO. 03 to F *N9 90 E Januar y T i a J d e 1979 ClIou d 20 0 t0i 1 31 " -M No n t h I y 90 w Fig. 14 The monthly...r- 4 -Vto C UovjS 3H 3AOV 30 IJWII H913Hono-4 9__ . bases. The cloud amount from the visual satellite processor is obtained by comparing the 64...satellite analyses are combined to produce a single satellite c .. 10 1n 0 a 0 c ____ ___ ____ ___ ____ ___ a__ _ a0 0 0 "w -4 O *0u mC 07 o v" 0 0. cr. 4" L

Preparation of Zn(BH4)2 and diborane and hydrogen release properties of Zn(BH4)2+xMgH2 (x=1, 5, 10, and 15)

NASA Astrophysics Data System (ADS)

Kwak, Young Jun; Kwon, Sung Nam; Song, Myoung Youp

2015-09-01

Zn(BH4)2 was prepared by milling ZnCl2 and NaBH4 in a planetary ball mill under Ar atmosphere, and Zn(BH4)2+xMgH2 (x=1, 5, 10, and 15) samples were prepared. Diborane (B2H6) and hydrogen release characteristics of the Zn(BH4)2 and Zn(BH4)2+xMgH2 samples were studied. The samples synthesized by milling ZnCl2 and NaBH4 contained Zn(BH4)2 and NaCl, together with small amounts of ZnCl2 and NaBH4. We designated these samples as Zn(BH4)2(+NaCl). The weight loss up to 400 °C of the Zn(BH4)2(+NaCl) sample synthesized by milling 4 h was 11.2 wt%. FT-IR analysis showed that Zn(BH4)2 was formed in the Zn(BH4)2(+NaCl) samples. MgH2 was also milled in a planetary ball mill, and mixed with the Zn(BH4)2(+NaCl) synthesized by milling for 4 h in a mortar and pestle. The weight loss up to 400 °C of Zn(BH4)2(+NaCl)+MgH2 was 8.2 wt%, corresponding to the weight % of diborane and hydrogen released from the Zn(BH4)2(+NaCl)+MgH2 sample, with respect to the sample weight. DTA results of Zn(BH4)2(+NaCl)+xMgH2 showed that the decomposition peak of Zn(BH4)2 was at about 61 °C, and that of MgH2 was at about 370-389 °C.

Experimental Determination of Solubilities of Tri-calcium Di-Citrate Tetrahydrate [Ca 3[C 3H 5O(COO) 3] 2•4H 2O] Earlandite in NaCl and MgCl 2 Solutions to High Ionic Strengths and Its Pitzer Model: Applications to Nuclear Waste Isolation and Other Low Temperature Environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Yongliang; Kirkes, Leslie Dawn; Westfall, Terry

In this study, solubility measurements on tri-calcium di-citrate tetrahydrate [Ca 3[C 3H 5O(COO) 3]2•4H 2O, abbreviated as Ca 3[Citrate] 2•4H 2O] as a function of ionic strength are conducted in NaCl solutions up to I = 5.0 mol•kg –1 and in MgCl 2 solutions up to I = 7.5 mol•kg –1, at room temperature (22.5 ± 0.5°C). The solubility constant (log Kmore » $$0\\atop{sp}$$) for Ca 3[Citrate] 2•4H 2O and formation constant (logβ$$0\\atop{1}$$) for Ca[C 3H 5O(COO) 3] –Ca 3[C 3H 5O(COO) 3] 2•4H 2O (earlandite) = 3Ca 2+ + 2[C 3H 5O(COO) 3] 3– + 4H 2O (1) Ca 2+ + [C 3H 5O(COO) 3] 3– = Ca[C 3H 5O(COO) 3] – (2) are determined as –18.11 ± 0.05 and 4.97 ± 0.05, respectively, based on the Pitzer model with a set of Pitzer parameters describing the specific interactions in NaCl and M gCl 2 media.« less

One pot synthesis of two Mn(II) perchlorate complexes with s-triazine NNN-pincer ligand; molecular structure, Hirshfeld analysis and DFT studies

NASA Astrophysics Data System (ADS)

Soliman, Saied M.; El-Faham, Ayman

2018-07-01

Self assembly of Mn(II) perchlorate and bis(pyrazolo)-s-triazine pincer ligand (L) in methanol-water mixture afforded the homoleptic [MnL2](ClO4)2 complex (1) as plate colorless crystals. Following the crystallization process till the near dryness of the solution, we noted few needle like crystals of the heteroleptic [MnL(H2O)3](ClO4)2·H2O complex (2). Their molecular and supramolecular structures were analyzed using single crystal structure combined with Hirshfeld analysis. The packing of complexes 1 and 2 is dominated by weak Csbnd H⋯O and strong Osbnd H⋯O hydrogen bonds, respectively, as well as anion-π stacking interactions. Using Hirshfeld analysis, the percentages of the O⋯H intermolecular contacts are 32.7% and 36.8% for 1 and 2, respectively. The Mnsbnd N distances correlated well with the atoms in molecules (AIM) topological parameters. The amount of electron density transferred from the ligand units to the manganese centre are nearly the same (0.9 e) in both complexes.

Isopycnic Phases and Structures in H2O/CO2/Ethoxylated Alcohol Surfactant Mixtures

NASA Technical Reports Server (NTRS)

Paulaitis, Michael E.; Zielinski, Richard G.; Kaler, Eric W.

1996-01-01

Ternary mixtures of H2O and CO2 with ethoxylated alcohol (C(i)E(j)) surfactants can form three coexisting liquid phases at conditions where two of the phases have the same density (isopycnic phases). Isopycnic phase behavior has been observed for mixtures containing the surfactants C8E5, C10E6, and C12E6, but not for those mixtures containing either C4E1 or CgE3. Pressure-temperature (PT) projections for this isopycnic three-phase equilibrium were determined for H2O/CO2/C8E5 and H2O/CO2/C10E6 mixtures at temperatures from approximately 25 to 33 C and pressures between 90 and 350 bar. As a preliminary to measuring the microstructure in isopycnic three component mixtures, phase behavior and small angle neutron scattering (SANS) experiments were performed on mixtures of D2O/CO2/ n-hexaethyleneglycol monododecyl ether (C12E6) as a function of temperature (25-31 C), pressure (63.1-90.7 bar), and CO2 composition (0-3.9 wt%). Parameters extracted from model fits of the SANS spectra indicate that, while micellar structure remains essentially unchanged, critical concentration fluctuations increase as the phase boundary and plait point are approached.

Effect of stress induced by suboptimal growth factors on survival of Escherichia coli O157:H7.

PubMed

Uyttendaele, M; Taverniers, I; Debevere, J

2001-05-21

This study investigated the growth and survival of E. coli O157:H7 exposed to a combination of suboptimal factors (22 degrees C, 7 degrees C, -18 degrees C/0.5% NaCl, 5.0% NaCl/pH 7.0, pH 5.4, pH 4.5/addition of lactic acid) in a simulation medium for red meat (beef gravy). Prolonged survival was noted as the imposed stress was more severe, and as multiple growth factors became suboptimal. At a defined temperature (7 degrees C or -18 degrees C), survival was prolonged at the more acid, more suboptimal pH (pH 4.5 > pH 5.4 > pH 7.0) while at a defined pH (pH 4.5), better survival was observed at 7 degrees C than at 22 degrees C. This suggests that application of the hurdle concept for preservation of food may inhibit outgrowth but induce prolonged survival of E. coli O157:H7 in minimal processed foods. At both 22 degrees C and 7 degrees C, the addition of lactic acid instead of HCl to reduce pH (to pH 4.5) resulted in a more rapid decrease of E. coli O157:H7. High survival was observed in beef gravy, pH 5.4 at -18 degrees C (simulation of frozen meat)-reduction of log 3.0 to log 1.9 after 43 days--and in beef gravy, pH 4.5 and 5% NaCl at 7 degrees C (simulation of a fermented dried meat product kept in refrigeration)--less than 1 log reduction in 43 days. In these circumstances, however, a high degree of sublethal damage of the bacterial cells was noted. The degree of sublethal damage can be estimated from the difference in recovery of the pathogen on the non-selective TSA medium and the selective SMAC medium.

INTERACTION ANALYSES OF BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3H1OT1/2CL8 MOUSE EMBRYO FIBROBLASTS IN CULTURE.

EPA Science Inventory

Studies of defined mixtures of carcinogenic polycyclic aromatic hydrocarbons (PAH) have shown three major categories of interactions: antagonism, synergism, and additivity depending on the biological model, tissue, route of exposure, and specific PAH. To understand the bases of t...

Oligomeric stability of Rapana venosa hemocyanin (RvH) and its structural subunits.

PubMed

Dolashka-Angelova, Pavlina; Schwarz, Heinz; Dolashki, Aleksandar; Stevanovic, Stefan; Fecker, Miriam; Saeed, Muhammad; Voelter, Wolfgang

2003-03-21

The two structural subunits RvH1 and RvH2 were separated after overnight dialysis of Rapana venosa Hc against 130 mM Gly/NaOH buffer, pH 9.6, on an ion exchange column Hiload 26/10 Sepharose Q using a fast performance liquid chromatography (FPLC) system. The reassociation characteristics of these two RvH isoforms and the native molecule were studied in buffers with different pH values and concentrations of Ca(2+) and Mg(2+). Reassociation of mixed RvH subunits was performed over a period of several days using a stabilizing buffer (SB) of pH 7.0 containing different concentrations of Ca(2+) and Mg(2+) ions. After 2 days of dialysis, an RvH subunit mixture of didecamers and multidecamers was observed in the presence of 100 mM CaCl(2) and MgCl(2), though RvH1 and RvH2 are biochemically and immunologically different and have also different dissociation properties. The reassociation, performed at pH 9.6 with 2 mM CaCl(2) and MgCl(2) at 4 degrees C over a period of one to several weeks, led to the formation of decameric oligomers, while didecamers formed predominantly in the SB at pH 7.0. Higher concentrations of calcium and magnesium ions led to a more rapid reassociation of RvH1 resulting in long stable multidecamers and helical tubules, which were stable and slowly dissociated into shorter multidecamers and decamers at higher pH values. The reassociation of the RvH2 structural subunit in the same buffers processed slowly and yielded didecamers, shorter tubule polymers and long multidecamers which are less stable at higher pH values. The stability of RvH isoforms under varying ionic conditions is compared with the stability of keyhole limpet (KLH, Megathura crenulata) hemocyanin (KLH) and Haliotis tuberculata hemocyanin (HtH) isoforms. The process of dissociation and reassociation is connected with changes of the fluorescence intensity at 600 nm, which can be explained by differences in opalescence of the solutions of these two isoforms. The solutions of longer tubule polymers and multidecamers of RvH1 show a higher opalescence compared to the solutions of shorter helical tubules and multidecamers of RvH2.

Determination Co 2+ in vitamin B 12 based on enhancement of 2-(4-substituted-phenyl)-4,5-di(2-furyl) imidazole and H 2O 2 chemiluminescence reaction

NASA Astrophysics Data System (ADS)

Han, Lu; Zhang, Yumin; Kang, Jing; Tang, Jieli; Zhang, Yihua

2011-11-01

In this paper, three kinds of imidazole derivatives, 2-(4-methylphenyl)-4,5-di(2-furyl) imidazole (MDFI), 2-(4-nitrophenyl)-4,5-di(2-furyl) imidazole (NDFI), and 2-(4-tert-butylphenyl)-4,5-di(2-furyl) imidazole (t-BDFI) were synthesized. In an alkaline medium, the chemiluminescence (CL) reaction of imidazole derivatives with H 2O 2 has been investigated. It was also found that MDFI/H 2O 2 and t-BDFI/H 2O 2 systems gave strong CL. When Co 2+ was added into the two CL systems, the CL intensity was remarkably enhanced. In the optimum conditions, the CL intensity is linearly related to the logarithm of concentration of Co 2+. The linear ranges are 5 × 10 -9-2.5 × 10 -7 mol/L for MDFI/H 2O 2 system and 5 × 10 -9-2.5 × 10 -7 mol/L for t-BDFI/H 2O 2 system, and the corresponding detection limits are 1.2 × 10 -9 mol/L and 1.1 × 10 -9 mol/L, respectively. The method was applied to the determination of Co 2+ in vitamin B 12 injection. Furthermore, the CL mechanism was also discussed.

Carbonate mineral solubility at low temperatures in the Na-K-Mg-Ca-H-Cl-SO 4-OH-HCO 3-CO 3-CO 2-H 2O system

NASA Astrophysics Data System (ADS)

Marion, Giles M.

2001-06-01

Carbonate minerals have played an important role in the geochemical evolution of Earth, and may have also played an important role in the geochemical evolution of Mars and Europa. Several models have been published in recent years that describe chloride and sulfate mineral solubilities in concentrated brines using the Pitzer equations. Few of these models are parameterized for subzero temperatures, and those that are do not include carbonate chemistry. The objectives of this work are to estimate Pitzer-equation bicarbonate-carbonate parameters and carbonate mineral solubility products and to incorporate them into the FREZCHEM model to predict carbonate mineral solubilities in the Na-K-Mg-Ca-H-Cl-SO 4-OH-HCO 3-CO 3-CO 2-H 2O system at low temperatures (≤25°C) with a special focus on subzero temperatures. Most of the Pitzer-equation parameters and equilibrium constants are taken from the literature and extrapolated into the subzero temperature range. Solubility products for 14 sodium, potassium, magnesium, and calcium bicarbonate and carbonate minerals are included in the model. Most of the experimental data are at temperatures ≥ -8°C; only for the NaHCO 3-NaCl-H 2O and Na 2CO 3-NaCl-H 2O systems are there bicarbonate and carbonate data to temperatures as low as -21.6°C. In general, the fit of the model to the experimental data is good. For example, calculated eutectic temperatures and compositions for NaHCO 3, Na 2CO 3, and their mixtures with NaCl and Na 2SO 4 salts are in good agreement with experimental data to temperatures as low as -21.6°C. Application of the model to eight saline, alkaline carbonate waters give predicted pHs ranging from 9.2 to 10.2, in comparison with measured pHs that range from 8.7 to 10.2. The model suggests that the CaCO 3 mineral that precipitates during seawater freezing is probably calcite and not ikaite. The model demonstrates that a proposed salt assemblage for the icy surface of Europa consisting of highly hydrated MgSO 4 salts and natron (Na 2CO 3 · 10H 2O) is an incompatible salt assemblage.

Infrared spectra of the 1-pyridinium (C5H5NH+) cation and pyridinyl (C5H5NH and 4-C5H6N) radicals isolated in solid para-hydrogen.

PubMed

Golec, Barbara; Das, Prasanta; Bahou, Mohammed; Lee, Yuan-Pern

2013-12-19

Protonated pyridine and its neutral counterparts (C5H6N) are important intermediates in organic and biological reactions and in the atmosphere. We have recorded the IR absorption spectra of the 1-pyridinium (C5H5NH(+)) cation, 1-pyridinyl (C5H5NH), and 4-pyridinyl (4-C5H6N) produced on electron bombardment during matrix deposition of a mixture of pyridine (C5H5N) and p-H2 at 3.2 K; all spectra were previously unreported. The IR features of C5H5NH(+) diminished in intensity after the matrix was maintained in darkness for 15 h, whereas those of C5H5NH and 4-C5H6N radicals increased. Irradiation of this matrix with light at 365 nm diminished lines of C5H5NH(+) and C5H5NH but enhanced lines of 4-C5H6N slightly, whereas irradiation at 405 nm diminished lines of 4-C5H6N significantly. Observed wavenumbers and relative intensities of these species agree satisfactorily with the anharmonic vibrational wavenumbers and IR intensities predicted with the B3LYP/6-31++G(d,p) method. Assignments of C5H5NH and 4-C5H6N radicals were further supported by the observation of similar spectra when a Cl2/C5H5N/p-H2 matrix was irradiated first at 365 nm and then with IR light to generate H atoms to induce the H + C5H5N reaction.

Trans- and cis-2-phenylindole platinum(II) complexes as cytotoxic agents against human breast adenocarcinoma cell lines

NASA Astrophysics Data System (ADS)

Tomé, Maria; López, Concepción; González, Asensio; Ozay, Bahadir; Quirante, Josefina; Font-Bardía, Mercè; Calvet, Teresa; Calvis, Carme; Messeguer, Ramon; Baldomá, Laura; Badía, Josefa

2013-09-01

The synthesis and characterization of the new 2-phenylindole derivative: C8H3N-2-C6H5-3NOMe-5OMe (3c) and the trans- and cis-isomers of [Pt(3c)Cl2(DMSO)] complexes (4c and 5c, respectively) are described. The crystal structures of 4c·CH2Cl2 and 5c confirm: (a) the existence of a Pt-Nindole bond, (b) the relative arrangement of the Cl- ligands [trans- (in 4c) or cis- (in 5c)] and (c) the anti-(E) configuration of the oxime. The cytotoxic assessment of C8H3N-2-(C6H4-4‧R1)-3NOMe-5R2 [with R1 = R2 = H (3a); R1 = Cl, R2 = H (3b) and R1 = H, R2 = OMe (3c)] and the geometrical isomers of [Pt(L)Cl2(DMSO)] with L = 3a-3c [trans- (4a-4c) and cis- (5a-5c), respectively] against human breast adenocarcinoma cell lines (MDA-MB231 and MCF-7) is also reported and reveals that all the platinum(II) complexes (except 4a) are more cytotoxic than cisplatin in front of the MCF7 cell line. Electrophoretic DNA migration studies of the synthesized compounds in the absence and in the presence of topoisomerase-I have been performed, in order to get further insights into their mechanism of action.

GTE_TRACEP_P3B Parameters 1

Atmospheric Science Data Center

2013-02-19

... Methyl bromide (CH3Br) Bromopropane (C3H7 Br) Methyl Chloride (CH3Cl) Ethyl Chloride (C2H5Cl) Vinyl chloride (C2H3Cl) ... Trichloroethylene (C2HCl3) Tetrachloroethylene (C2Cl4) Methylene bromide (CH2Br2) Chlorodibromomethane (CHClBr2) Bromoform ...

Insights into the intramolecular donor stabilisation of organostannylene palladium and platinum complexes: syntheses, structures and DFT calculations.

PubMed

Wagner, Michael; Deáky, Vajk; Dietz, Christina; Martincová, Jana; Mahieu, Bernard; Jambor, Roman; Herres-Pawlis, Sonja; Jurkschat, Klaus

2013-05-17

The syntheses of the transition metal complexes cis-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)2MX2] (1, M = Pd, X = Cl; 2, M = Pd, X = Br; 3, M = Pd, X = I; 4, M = Pt, X = Cl), cis-[{2,6-(Me2NCH2)2C6H3SnCl}2MX2] (5, M = Pd, X = I; 6, M = Pt, X = Cl), trans-[{2,6-(Me2NCH2)2C6H3SnI}2PtI2] (7) and trans-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)PdI2]2 (8) are reported. Also reported is the serendipitous formation of the unprecedented complexes trans-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)2Pt(SnCl3)2] (10) and [(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)3Pt(SnCl3)2] (11). The compounds were characterised by elemental analyses, (1)H, (13)C, (31)P, (119)Sn and (195)Pt NMR spectroscopy, single-crystal X-ray diffraction analysis, UV/Vis spectroscopy and, in the cases of compounds 1, 3 and 4, also by Mössbauer spectroscopy. All the compounds show the tin atoms in a distorted trigonal-bipyramidal environment. The Mössbauer spectra suggest the tin atoms to be present in the oxidation state III. The kinetic lability of the complexes was studied by redistribution reactions between compounds 1 and 3 as well as between 1 and cis-[{2,6-(Me2 NCH2)2C6H3SnCl}2PdCl2]. DFT calculations provided insights into both the bonding situation of the compounds and the energy difference between the cis and trans isomers. The latter is influenced by the donor strength of the pincer-type ligands. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental ion mobility measurements in Xe-C2H6

NASA Astrophysics Data System (ADS)

Perdigoto, J. M. C.; Cortez, A. F. V.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

2017-10-01

In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon (Xe) with ethane (C2H6) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 Td to 25 Td range (2.4-6.1 kVṡcm-1ṡ bar-1), at room temperature. The time of arrival spectra revealed two peaks throughout the entire range studied which were attributed to ion species with 3-carbons (C3H5+, C3H6+ C3H8+ and C3H9+) and with 4-carbons (C4H7+, C4H9+ and C4H10+). Besides these, and for Xe concentrations above 70%, a bump starts to appear at the right side of the main peak for reduced electric fields higher than 20 Td, which was attributed to the resonant charge transfer of C2H6+ to C2H6 that affects the mobility of its ion products (C3H8+ and C3H9+). The time of arrival spectra for Xe concentrations of 20%, 50%, 70% and 90% are presented, together with the reduced mobilities as a function of the Xe concentration calculated from the peaks observed for the low reduced electric fields and pressures studied.

High pressure micromechanical force measurements of the effects of surface corrosion and salinity on CH4/C2H6 hydrate particle-surface interactions.

PubMed

Wang, Shenglong; Hu, Sijia; Brown, Erika P; Nakatsuka, Matthew A; Zhao, Jiafei; Yang, Mingjun; Song, Yongchen; Koh, Carolyn A

2017-05-24

In order to investigate the mechanism of gas hydrate deposition and agglomeration in gas dominated flowlines, a high-pressure micromechanical force (MMF) apparatus was applied to directly measure CH 4 /C 2 H 6 hydrate adhesion/cohesion forces under low temperature and high pressure conditions. A CH 4 /C 2 H 6 gas mixture was used as the hydrate former. Adhesion forces between hydrate particles and carbon steel (CS) surfaces were measured, and the effects of corrosion on adhesion forces were analyzed. The influences of NaCl concentration on the cohesion force between CH 4 /C 2 H 6 hydrate particles were also studied for gas-dominated systems. It was observed that there was no measurable adhesion force for pristine (no corrosion) and corroded surfaces, when there was no condensed water or water droplet on these surfaces. With water on the surface (the estimated water amount was around 1.7 μg mm -2 ), a hydrate film growth process was observed during the measurement. CS samples were soaked in NaCl solution to obtain different extents of corrosion on surfaces, and adhesion measurements were performed on both pristine and corroded samples. The adhesion force was found to increase with increasing soak times in 5 wt% NaCl (resulting in more visual corrosion) by up to 500%. For the effect of salinity on cohesion forces, it was found that the presence of NaCl decreased the cohesion force between hydrate particles, and a possible explanation of this phenomenon was given based on the capillary liquid bridge model.

Polymethylated [Fe(η6-arene)2]2+ dications: methyl-group rearrangements and application of the EINS mechanism.

PubMed

Štíbr, Bohumil; Bakardjiev, Mario; Hájková, Zuzana; Holub, Josef; Padělková, Zdenka; Růžička, Aleš; Kennedy, John D

2011-06-14

Reactions between the methylated arenes ArMe(n) [where ArMe(n) = C(6)Me(n)H((6-n)), and n = 1-6] and FeCl(2) in heptane at 90 °C in the presence of anhydrous AlCl(3) give, for the arenes with n = 1-5, extensive isomerisations and disproportionations involving the methyl groups on the arene rings, and the formation of mixtures of [Fe(ArMe(n))(2)](2+) dications that defy separation into pure species. GC-MS studies of AlCl(3)/mesitylene and AlCl(3)/durene reactions in the absence of FeCl(2) (90 °C, 2 h) allow quantitative assessments of the rearrangements, and the EINS mechanism (electrophile-induced nucleophilic substitution) is applied to rationalise the phenomena. By contrast, ArMe(n) / FeCl(2) /AlCl(3) reactions in heptane for 24-36 h at room-temperature proceed with no rearrangements, allowing the synthesis of the complete series of pure [Fe(ArMen)](2+) cations in yields of 48-71%. The pure compounds are characterised by (1)H NMR spectroscopy and electrospray-ionization mass-spectrometry (ESI-MS), and the structures of [Fe(m-xylene)(2)][PF(6)](2) and [Fe(durene)(2)][PF(6)](2) are established by single-crystal X-ray diffraction analyses.

Kinetics and Thermochemistry of ClCO Formation from the Cl + CO Association Reaction

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Kreutter, K. D.; Wine, P. H.

1997-01-01

Laser flash photolysis of Cl2/CO/M mixtures (M = N2, CO, Ar, CO2) has been employed in conjunction with Cl((sup 2)P(sub J)) detection by time-resolved resonance fluorescence spectroscopy to investigate equilibration kinetics in the reactions Cl((sup 2)P(sub J)) + CO ClCO as a function of temperature (185-260 K) and pressure (14-200 Torr). The association and dissociation reactions are found to be in the low-pressure limit over the range of experimental conditions investigated. In N2 and/or CO buffer gases, the temperature dependences of the ClCO formation and dissociation reaction rate constants are described by the Arrhenius expressions k(sub 1) = (1.05 +/- 0.36) x 10(exp -34) exp[(810 +/- 70)/T] cm(exp 6)/molecules(exp 2).s and k(sub -1) = (4.1 +/- 3.1) x 10(exp -10) exp[(-2960 +/- 60)/T]cu cm/(molecule.s) (errors are 2 sigma). Second- and third-law analyses of the temperature dependence of the equilbrium constant (k/k-1) lead to the following thermodynamic parameters for the association reaction: Delta-H(sub 298) = -7.7 +/- 0.6 kcal/mol, Delta-H(sub 0) = -6.9 +/- 0.7 kcal/mol, Delta-S(sub 298) = -23.8 +/- 2.0 cal/mole.K, Delta-H(sub f,298)(ClCO) = 5.2 +/- 0.6 kcal/mol (errors are 2 sigma). The results repported in this study significantly reduce the uncertainties in all reported kinetic and thermodynamic parameters.

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place. Part 9 (Florida Offshore Inc -Gerhart Holding Company Inc)

DTIC Science & Technology

1990-01-01

5 0 82 91-01353 375 pages Z- ZI-M a 0 U) N000)))))000 -4 r- K WILIM.- K 0o 0 -4-40000000O~000 C100000000 0 )K K -K K zzzzzz zzzzzzzzz onJ...N * 040 < 4 < 4 << 4444 444 444 44 4 < H 0 - Hm0. 0 .. N CL 00. I L L coc co0( Comm 000 3 0 H L0-4C’) 0 I H ::c) 5 0 40 0 . 00-000 000. C 00. 000, 0 0 L...HIS ( 0 -END H N ) Cl) NP4 -Ps- -N" r- -P 444 V4 S) I-( c H 4 S ( 0 -E"ND " 5

Di-tert-butyl-chlorido(N,N-dibenzyl-dithio-carbamato)tin(IV).

PubMed

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R T

2011-02-26

The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)(C(15)H(14)NS(2))Cl], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl atom and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former.

Syntheses and molecular structures of novel Ru(II) complexes with bidentate benzimidazole based ligands and their catalytic efficiency for oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Dayan, Osman; Tercan, Melek; Özdemir, Namık

2016-11-01

Five bidentate ligands derived from quinoline-2-carboxylic acid, i.e. 2-(1H-benzimidazol-2-yl)quinoline (L1), 2-(1-benzyl-1H-benzimidazol-2-yl)quinoline (L2), 2-[1-(2,3,5,6-tetramethylbenzyl)-1H-benzimidazol-2-yl]quinoline (L3), 2-[1-(4-chlorobenzyl)-1H-benzimidazol-2-yl]quinoline (L4), and 2-[1-(4-methylbenzyl)-1H-benzimidazol-2-yl]quinoline (L5) were synthesized. Treatment of L1-5 with [RuCl2(p-cymene)]2 and KPF6 afforded six-coordinate piano-stool Ru(II) complexes, namely, [RuCl(L1)(p-cymene)]PF6 (C1), [RuCl(L2)(p-cymene)]PF6 (C2), [RuCl(L3)(p-cymene)]PF6 (C3), [RuCl(L4)(p-cymene)]PF6 (C4), and [RuCl(L5)(p-cymene)]PF6 (C5). Synthesized compounds were characterized with different techniques such as 1H and 13C NMR, FT-IR, and UV-vis spectroscopy. The solid state structure of L1 and C3 was confirmed by single-crystal X-ray diffraction analysis. The single crystal structure of C3 verified coordination of L3 to the Ru(II) center. The Ru(II) center has a pseudo-octahedral three legged piano stool geometry. The complexes C1-5 were tested as catalysts for the catalytic oxidation of benzyl alcohol to benzaldehyde in the presence of periodic acid (H5IO6) (Substrate/Catalyst/Oxidant = 1/0.01/0.5). The best result was obtained with C2 (3 h→90%).

Dinuclear Nickel(II) Complexes as Models for the Active Site of Urease.

PubMed

Volkmer, Dirk; Hommerich, Birgit; Griesar, Klaus; Haase, Wolfgang; Krebs, Bernt

1996-06-19

Dinuclear nickel(II) complexes of the ligands 2,6-bis[bis((2-benzimidazolylmethyl)amino)methyl]-p-cresol (bbapOH), N,N,N',N'-tetrakis(2-benzimidazolylmethyl)-2-hydroxy-1,3-diaminopropane (tbpOH), N-methyl-N,N',N'-tris(2-benzimidazolylmethyl)-2-hydroxy-1,3-diaminopropane (m-tbpOH) and 1-[N,N-bis(2-benzimidazolylmethyl)amino]-3-[2-(3,5-dimethyl-1H-pyrazol-1-yl)ethoxy]-2-hydroxypropane (bpepOH) were prepared in order to model the active site of urease. The novel asymmetric structures of the dinuclear complexes were characterized by X-ray structure analysis. The complex [Ni(2)(bbapO)(ClO(4))(H(2)O)(MeOH)](ClO(4))(2).Et(2)O, 1, crystallizes in the monoclinic space group P2(1)/c, with a = 10.258(2) Å, b = 19.876(3) Å, c = 25.592(4) Å, and beta = 97.12(2) degrees. The nickel ions in 1 are bridged by the phenoxy donor of the ligand and a perchlorate anion. The complexes [Ni(2)(tbpO)(MeCOO)(H(2)O)](ClO(4))(2).H(2)O.Et(2)O, 2, [Ni(2)(m-tbpO)(PhCOO)(EtOH)(2)](ClO(4))(2).EtOH, 3, and [Ni(2)(bpepO)(MeCOO)(H(2)O)(2)](ClO(4))(2).H(2)O.Et(2)O.2EtOH, 4, also crystallize in the monoclinic crystal system with the following unit cell parameters: 2, C2/c, a = 35.360(13) Å, b = 10.958(3) Å, c = 24.821(10) Å, beta = 103.55(3) degrees; 3, Cc, a = 14.663(5) Å, b = 32.630(13) Å, c = 9.839(3) Å, beta = 92.49(2) degrees; 4, C2/c, a = 27.689(13) Å, b = 12.187(5) Å, c = 31.513(14) Å, beta = 115.01(3) degrees. The dinuclear centers of all these complexes are bridged by the alkoxy donor of the ligand and a carboxylate function. Compounds 2 and 3 have one of the nickel ions in a five-coordinated, trigonal bipyramidal coordination environment and thus show a high structural similarity to the dinuclear active site of urease from Klebsiella aerogenes. Furthermore, their magnetic and spectroscopic properties were determined and related to those of the urease enzymes. Activity toward hydrolysis of test substrates (4-nitrophenyl)urea, 4-nitroacetanilide, 4-nitrophenyl phosphate or bis(4-nitrophenyl) phosphate by the dinuclear complexes were examined by UV spectroscopic measurements.

Thermochemistry and Kinetics of the Cl+O2 Association Reaction

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Kreutter, K. D.; Shackelford, C. J.; Wine, P. H.

1997-01-01

Laser flash photolysis of Cl2/O2 mixtures has been employed in conjunction with Cl((sup 2)P(sub 3/2)) detection by time-resolved fluorescence spectroscopy to investigate equilibration kinetics for the reactions Cl + O2 + O is in equilibrium with ClOO + O2 at temperatures of 181-200 K and O2 pressures of 15-40 Torr. The third-order rate coefficient for the association reaction at 186.5 +/- 5.5 K is (8.9 +/- 2.9) x 10(exp -33) cm(exp 6) molecule(exp -2) s(exp -1) and the equilibrium constant (K(p)) at 185.4 K is 18.9 atm(exp -1) (factor of 1.7 uncertainty). A third law analysis of our data leads to a value for the Cl-OO bond dissociation energy of 4.76 +/- 0.49 kcal mol(exp -1).

Influence of dosage, pH and contact time in stabilized landfill leachate treatment using ozone/zirconium tetrachloride catalytic oxidation

NASA Astrophysics Data System (ADS)

Zakaria, Siti Nor Farhana; Aziz, Hamidi Abdul

2017-10-01

Leachate is a critical problem of sanitary landfills because it contains high organic matter and hazardous compounds that can generate negative environmental effects. The high chemical oxygen demand (COD) and color of the leachate necessitates its treatment before it can be released to the water body. Thus, an investigation into the performance of advanced oxidation processes (AOPs) was conducted using a combination of ozone (O3) with zirconium tetrachloride (ZrCl4) as catalyst in stabilized landfill leachate treatment. Such leachate was collected from the Alor Pongsu Landfill site (APLS), Perak, Malaysia. COD and color parameter were used as indicators to examine the effect of O3/ZrCl4 dosage, pH, and contact time. The experiment was run under gas flow rate of 1,000 mL/min±10% and temperature below 15 °C. The maximum removal obtained for COD and color were 88% and 100%, respectively. This outcome was achieved at 27 g/m3 ozone dosage, pH 6, 90 min reaction time, and dosage ratio of 1:2 (COD g: ZrCl4 g). The reaction rate constant (k) was 0.2364 min-1 and followed pseudo first order. Thus, given the efficiency of the O3/ZrCl4 mixture for the remediation of stabilized landfill leachate, a new alternative method in leachate industrial treatment was identified.

Microbial Degradation of a Recalcitrant Pesticide: Chlordecone.

PubMed

Chaussonnerie, Sébastien; Saaidi, Pierre-Loïc; Ugarte, Edgardo; Barbance, Agnès; Fossey, Aurélie; Barbe, Valérie; Gyapay, Gabor; Brüls, Thomas; Chevallier, Marion; Couturat, Loïc; Fouteau, Stéphanie; Muselet, Delphine; Pateau, Emilie; Cohen, Georges N; Fonknechten, Nuria; Weissenbach, Jean; Le Paslier, Denis

2016-01-01

Chlordecone (Kepone®) is a synthetic organochlorine insecticide (C 10 Cl 10 O) used worldwide mostly during the 1970 and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 μg/mL) in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C 9 Cl 5 H 3 (named B1) as well as two minor metabolites C 10 Cl 9 HO (named A1) and C 9 Cl 4 H 4 (named B3). Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus , and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process.

Microbial Degradation of a Recalcitrant Pesticide: Chlordecone

PubMed Central

Chaussonnerie, Sébastien; Saaidi, Pierre-Loïc; Ugarte, Edgardo; Barbance, Agnès; Fossey, Aurélie; Barbe, Valérie; Gyapay, Gabor; Brüls, Thomas; Chevallier, Marion; Couturat, Loïc; Fouteau, Stéphanie; Muselet, Delphine; Pateau, Emilie; Cohen, Georges N.; Fonknechten, Nuria; Weissenbach, Jean; Le Paslier, Denis

2016-01-01

Chlordecone (Kepone®) is a synthetic organochlorine insecticide (C10Cl10O) used worldwide mostly during the 1970 and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 μg/mL) in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C9Cl5H3 (named B1) as well as two minor metabolites C10Cl9HO (named A1) and C9Cl4H4 (named B3). Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus, and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process. PMID:28066351

A series of (E)-5-(arylideneamino)-1-tert-butyl-1H-pyrrole-3-carbonitriles and their reduction products to secondary amines: syntheses and X-ray structural studies.

PubMed

Macías, Mario A; Castillo, Juan Carlos; Portilla, Jaime

2018-01-01

An efficent access to a series of N-(pyrrol-2-yl)amines, namely (E)-1-tert-butyl-5-[(4-chlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 16 ClN 3 , (7a), (E)-1-tert-butyl-5-[(2,4-dichlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 15 Cl 2 N 3 , (7b), (E)-1-tert-butyl-5-[(pyridin-4-ylmethylene)amino]-1H-pyrrole-3-carbonitrile, C 15 H 16 N 4 , (7c), 1-tert-butyl-5-[(4-chlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 18 ClN 3 , (8a), and 1-tert-butyl-5-[(2,4-dichlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 17 Cl 2 N 3 , (8b), by a two-step synthesis sequence (solvent-free condensation and reduction) starting from 5-amino-1-tert-butyl-1H-pyrrole-3-carbonitrile is described. The syntheses proceed via isolated N-(pyrrol-2-yl)imines, which are also key synthetic intermediates of other valuable compounds. The crystal structures of the reduced compounds showed a reduction in the symmetry compared with the corresponding precursors, viz. Pbcm to P-1 from compound (7a) to (8a) and P2 1 /c to P-1 from compound (7b) to (8b), probably due to a severe change in the molecular conformations, resulting in the loss of planarity observed in the nonreduced compounds. In all of the crystals, the supramolecular assembly is controlled mainly by strong (N,C)-H...N hydrogen bonds. However, in the case of (7a)-(7c), C-H...Cl interactions are strong enough to help in the three-dimensional architecture, as observed in Hirshfeld surface maps.

Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles.

PubMed

Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

2014-10-01

To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles

PubMed Central

Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

2014-01-01

Objective: To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). Materials and Methods: The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. Results: There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. Conclusion: It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness. PMID:25512737

Synthesis and Structural Features of [4,4'-Diisopropoxyester-2,2'-bipyridine], [Dichloro(4,4'-diisopropoxyester-2,2'-bi-pyridine)-platinum(ii)] and Its Dichloromethane Solvated Pseudo-Polymorph: Versatile Supramolecular Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Browning, Charles; Nesterov, Vladimir N.; Wang, Xiaoping

We report that the organic ligand 4,4'-diisopropoxyester-2,2'-bipyridine, C 18H 20N 2O 4 (1), crystallizes in the triclinic crystal system P-1 and the molecule occupies a special position in the unit cell. In the crystal, molecules form stacks with partial overlapping of the pyridine rings. The Pt(II) dichloro complex of 1 crystallizes from a mixture of ethanol/hexane and from dichloromethane to form orange and yellow crystals, respectively. The orange non-solvated crystals of the (bipyridine)(dichloro)platinum(II) complex C 18H 20N 2O 4PtCl 2 (2) crystallize in the triclinic crystal system P-1 as well with two independent molecules in the unit cell. In themore » crystal packing, molecules form two types of dimers with Pt1 ··· Pt1A and Pt2···Pt2A distances of 3.478 and 5.186 angstrom respectively. The yellow crystals, as a solvated pseudo-polymorph C 18H 20N 2O 4PtCl 2·1.5 CH 2Cl 2 (3) also crystallize in the triclinic crystal system P-1 with two independent molecules in the unit cell. In the crystal packing, molecules form Pt2 ···Pt1 ···Pt1A ···Pt2A intermolecular contacts with alternating distances 3.501 and 3.431 angstrom, respectively, forming infinite chains. Graphical Abstract The dichloro(bipyridine)platinum complex, dichloro(4,4'-diisopropoxyester-2,2'-bipyridine)platinum(II), forms single crystals as a stable non-solvated form and a solvated polymorph with dramatically different supramolecular structure and short contacts.« less

Synthesis and Structural Features of [4,4'-Diisopropoxyester-2,2'-bipyridine], [Dichloro(4,4'-diisopropoxyester-2,2'-bi-pyridine)-platinum(ii)] and Its Dichloromethane Solvated Pseudo-Polymorph: Versatile Supramolecular Interactions

DOE PAGES

Browning, Charles; Nesterov, Vladimir N.; Wang, Xiaoping; ...

2015-06-03

We report that the organic ligand 4,4'-diisopropoxyester-2,2'-bipyridine, C 18H 20N 2O 4 (1), crystallizes in the triclinic crystal system P-1 and the molecule occupies a special position in the unit cell. In the crystal, molecules form stacks with partial overlapping of the pyridine rings. The Pt(II) dichloro complex of 1 crystallizes from a mixture of ethanol/hexane and from dichloromethane to form orange and yellow crystals, respectively. The orange non-solvated crystals of the (bipyridine)(dichloro)platinum(II) complex C 18H 20N 2O 4PtCl 2 (2) crystallize in the triclinic crystal system P-1 as well with two independent molecules in the unit cell. In themore » crystal packing, molecules form two types of dimers with Pt1 ··· Pt1A and Pt2···Pt2A distances of 3.478 and 5.186 angstrom respectively. The yellow crystals, as a solvated pseudo-polymorph C 18H 20N 2O 4PtCl 2·1.5 CH 2Cl 2 (3) also crystallize in the triclinic crystal system P-1 with two independent molecules in the unit cell. In the crystal packing, molecules form Pt2 ···Pt1 ···Pt1A ···Pt2A intermolecular contacts with alternating distances 3.501 and 3.431 angstrom, respectively, forming infinite chains. Graphical Abstract The dichloro(bipyridine)platinum complex, dichloro(4,4'-diisopropoxyester-2,2'-bipyridine)platinum(II), forms single crystals as a stable non-solvated form and a solvated polymorph with dramatically different supramolecular structure and short contacts.« less

Evaluation of phosphorus adsorption capacity of sesame straw biochar on aqueous solution: influence of activation methods and pyrolysis temperatures.

PubMed

Park, J H; Ok, Y S; Kim, S H; Cho, J S; Heo, J S; Delaune, R D; Seo, D C

2015-12-01

The phosphorus (P) adsorption characteristic of sesame straw biochar prepared with different activation agents and pyrolysis temperatures was evaluated. Between 0.109 and 0.300 mg L(-1) in the form of inorganic phosphate was released from raw sesame straw biochar in the first 1 h. The release of phosphate was significantly enhanced from 62.6 to 168.2 mg g(-1) as the pyrolysis temperature increased. Therefore, sesame straw biochar cannot be used as an adsorbent for P removal without change in the physicochemical characteristics. To increase the P adsorption of biochar in aqueous solution, various activation agents and pyrolysis temperatures were applied. The amount of P adsorbed from aqueous solution by biochar activated using different activation agents appeared in the order ZnCl2 (9.675 mg g(-1)) > MgO (8.669 mg g(-1)) ⋙ 0.1N-HCl > 0.1N-H2SO4 > K2SO4 ≥ KOH ≥ 0.1N-H3PO4, showing ZnCl2 to be the optimum activation agent. Higher P was adsorbed by the biochar activated using ZnCl2 under different pyrolysis temperatures in the order 600 °C > 500 °C > 400 °C > 300 °C. Finally, the amount of adsorbed P by activated biochar at different ratios of biochar to ZnCl2 appeared in the order 1:3 ≒ 1:1 > 3:1. As a result, the optimum ratio of biochar to ZnCl2 and pyrolysis temperature were found to be 1:1 and 600 °C for P adsorption, respectively. The maximum P adsorption capacity by activated biochar using ZnCl2 (15,460 mg kg(-1)) was higher than that of typical biochar, as determined by the Langmuir adsorption isotherm. Therefore, the ZnCl2 activation of sesame straw biochar was suitable for the preparation of activated biochar for P adsorption.

Synthesis of a new (1R)-(-)-myrtenal-derived dioxadithiadodecacycle and its use as an efficient chiral auxiliary.

PubMed

Vargas-Díaz, M Elena; Joseph-Nathan, Pedro; Tamariz, Joaquín; Zepeda, L Gerardo

2007-01-04

[reaction: see text] The new macrocycle 9 (>70% yield from hydroxythiol 10) was treated with several nucleophilic reagents (RMgX, RLi, and LiAlH4) affording carbinols 12a-j (80-96% yield, >99:1 dr). Oxidative hydrolysis of 12a,c,e, followed by LiAlH4 reduction of the resulting mixture, gave 16a,c,e in >95% ee,16c being a key precursor for the preparation of fungicide 17. The absolute configuration of 9 and 12j (Nu = H) was established by single-crystal X-ray diffraction analyses and chemical correlation.

Syntheses, Spectroscopic Data, and X-ray Diffraction Structures of the Heterometallic RuRe Face-shared Bioctahedral (eta(6)-cymene)Ru(mu-Cl)(3)Re(CO)(3) and MnRu2 Edge-shared Trioctahedral [fac-ClRu(CO)(3)](2)(mu-Cl)(4)Mn(H2O)(2) Complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiaoping; Hunt, Sean W; Richmond, Michael G.

2009-01-01

Thermolysis of the diruthenium compound [(eta(6)-cymene)RuCl2](2) (1) with ClRe(CO)(5) (2) leads to the formation of the new confacial bioctahedral compound (eta(6)-cymene) Ru(mu-Cl)(3)Re(CO)(3) (3) in good yields; the same product has also been isolated when a mixture of 1 and 2 is irradiated with near UV-vis light for an extended period of time. Heating 1 and ClMn(CO)(5) (4) does not furnish the corresponding manganese analogue of 3 but rather the trioctahedral halide-bridged product [fac-ClRu(CO)(3)](2)(mu-Cl)(4)Mn(H2O)(2) (5). 3 and 5 have been fully characterized in solution and their molecular structures established by X-ray crystallography.

Structure of salts of lithium chloride and lithium hexafluorophosphate as solvates with pyridine and vinylpyridine and structural comparisons: (C5H5N)LiPF6, [p-(CH2=CH)C5H4N]LiPF6, [(C5H5N)LiCl]n, and [p-(CH2=CH)C5H4N]2Li(μ-Cl)2Li[p-(CH2=CH)C5H4N]2.

PubMed

Jalil, AbdelAziz; Clymer, Rebecca N; Hamilton, Clifton R; Vaddypally, Shivaiah; Gau, Michael R; Zdilla, Michael J

2017-03-01

Due to the flammability of liquid electrolytes used in lithium ion batteries, solid lithium ion conductors are of interest to reduce danger and increase safety. The two dominating general classes of electrolytes under exploration as alternatives are ceramic and polymer electrolytes. Our group has been exploring the preparation of molecular solvates of lithium salts as alternatives. Dissolution of LiCl or LiPF 6 in pyridine (py) or vinylpyridine (VnPy) and slow vapor diffusion with diethyl ether gives solvates of the lithium salts coordinated by pyridine ligands. For LiPF 6 , the solvates formed in pyridine and vinylpyridine, namely tetrakis(pyridine-κN)lithium(I) hexafluorophosphate, [Li(C 5 H 5 N) 4 ]PF 6 , and tetrakis(4-ethenylpyridine-κN)lithium(I) hexafluorophosphate, [Li(C 7 H 7 N) 4 ]PF 6 , exhibit analogous structures involving tetracoordinated lithium ions with neighboring PF 6 - anions in the I-4 and Aea2 space groups, respectively. For LiCl solvates, two very different structures form. catena-Poly[[(pyridine-κN)lithium]-μ 3 -chlorido], [LiCl(C 5 H 5 N)] n , crystalizes in the P2 1 2 1 2 1 space group and contains channels of edge-fused LiCl rhombs templated by rows of π-stacked pyridine ligands, while the structure of the LiCl-VnPy solvate, namely di-μ-chlorido-bis[bis(4-ethenylpyridine-κN)lithium], [Li 2 Cl 2 (C 7 H 7 N) 4 ], is described in the P2 1 /n space group as dinuclear (VnPy) 2 Li(μ-Cl) 2 Li(VnPy) 2 units packed with neighbors via a dense array of π-π interactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weydert, M.; Brennan, J.G.; Andersen, R.A.

Reaction of (MeC{sub 5}H{sub 4}){sub 3}UX (X = Cl, MeC{sub 5}H{sub 4}) with t-BuLi affords the tertiary alkyl complex (MeC{sub 5}H{sub 4}){sub 3}U(t-Bu). Despite uranium(IV) generally being the preferred oxidation state in organometallic systems, (MeC{sub 5}H{sub 4}){sub 3}U(t-Bu) reacts with Lewis bases (L = PMe{sub 3}, THF, RCN, RNC) to yield the reduced uranium(III) base adducts (MeC{sub 5}H{sub 4}){sub 3}U(L). Carbon monoxide undergoes migratory insertion into the metal tertiary alkyl bond. The resulting acyl derivative decomposes at 90{degree}C to yield insoluble uranium-containing products and a mixture of tert-butyltoluenes by ring expansion of a methylcyclopentadienyl ligand. Ethylene also undergoes migratory insertionmore » into the metal tertiary alkyl bond. No subsequent insertion of ethylene into the metal carbon bond takes place after the first equivalent has inserted. In marked contrast, reaction of various (MeC{sub 5}H{sub 4}){sub 3}ThX (X = Cl, I, MeC{sub 5}H{sub 4}, O-2,6-Me{sub 2}C{sub 6}H{sub 3}, OTs) compounds with t-BuLi gave intractable materials. However, reaction of the cationic species [(RC{sub 5}H{sub 4}){sub 3}Th](BPh{sub 4}) (R = Me{sub 3}Si, t-Bu) with t-BuLi yields the new thorium hydrides (RC{sub 5}H{sub 4}){sub 3}ThH. 40 refs., 2 figs.« less

Crystal structures of 5-amino-N-phenyl-3H-1,2,4-di-thia-zol-3-iminium chloride and 5-amino-N-(4-chloro-phen-yl)-3H-1,2,4-di-thia-zol-3-iminium chloride monohydrate.

PubMed

Yeo, Chien Ing; Tan, Yee Seng; Tiekink, Edward R T

2015-10-01

The crystal and mol-ecular structures of the title salt, C8H8N3S2 (+)·Cl(-), (I), and salt hydrate, C8H7ClN3S2 (+)·Cl(-)·H2O, (II), are described. The heterocyclic ring in (I) is statistically planar and forms a dihedral angle of 9.05 (12)° with the pendant phenyl ring. The comparable angle in (II) is 15.60 (12)°, indicating a greater twist in this cation. An evaluation of the bond lengths in the H2N-C-N-C-N sequence of each cation indicates significant delocalization of π-electron density over these atoms. The common feature of the crystal packing in (I) and (II) is the formation of charge-assisted amino-N-H⋯Cl(-) hydrogen bonds, leading to helical chains in (I) and zigzag chains in (II). In (I), these are linked by chains mediated by charge-assisted iminium-N(+)-H⋯Cl(-) hydrogen bonds into a three-dimensional architecture. In (II), the chains are linked into a layer by charge-assisted water-O-H⋯Cl(-) and water-O-H⋯O(water) hydrogen bonds with charge-assisted iminium-N(+)-H⋯O(water) hydrogen bonds providing the connections between the layers to generate the three-dimensional packing. In (II), the chloride anion and water mol-ecules are resolved into two proximate sites with the major component being present with a site occupancy factor of 0.9327 (18).

Reaction of iron with hydrogen chloride-oxygen mixtures at 550 C

NASA Technical Reports Server (NTRS)

Jacobson, N. S.

1986-01-01

The reaction of iron with 1 percent HCl/0-50 percent O2/Ar has been studied at 550 C with thermogravimetry to monitor kinetics and scanning electron microscopy to characterize product morphologies. In addition, the volatile species were identified with an atmospheric pressure sampling mass spectrometer. The reaction of 1 percent HCl/Ar produces FeCl2. The reactions of 1 percent HCl/1, 10, 50 percent O2/Ar produce Fe2O3, Fe3O4, FeCl2, and FeCl3. In each case condensed phase chlorides form at the oxide/metal interface where the oxygen potential is low. The 10 and 50 percent oxygen mixtures have kinetics in the first 3 hr similar to pure oxidation with some deviations due to iron-chloride formation. The 1 percent oxygen mixture shows enhanced reaction rates over oxidation, very likely due to the formation of a porous scale.

Syntheses and structures of [UO2( L)5](ClO4)2 and [U( L')4(H2O)4](ClO4)4 ( L is dimethylformamide, L' is N,N-dimethylcarbamide)

NASA Astrophysics Data System (ADS)

Serezhkin, V. N.; Vologzhanina, A. V.; Pushkin, D. V.; Astashkina, D. A.; Savchenkov, A. V.; Serezhkina, L. B.

2017-09-01

The reaction of aqueous solutions of uranyl perchlorate with selected organic amides was studied in the dark and under the sunlight. The complexes [UVIO2(C3H7NO)5](ClO4)2 ( I) and [UIV(C3H8N2O)4(H2O)4](ClO4)4 ( II), where C3H7NO is N,N-dimethylformamide ( Dmfa) and C3H8N2O is N,N-dimethylcarbamide ( a-Dmur), were studied by X-ray diffraction. Complex II and the complex UIV( s-Dmur)4(H2O)4(ClO4)4 ( III), where s-Dmur is N,N'-dimethylcarbamide, were studied by IR spectroscopy. Crystals I and II are composed of mononuclear [UO2( Dmfa)5]2+ and [U( Dmur)4(H2O)4]4+ groups as uranium-containing structural units belonging to the crystal-chemical groups AM 7 1 ( A = UVI, M 1 = O2- and Dmfa) and AM 8 1 ( A = UIV, M 1 = Dmur and H2O) of uranium complexes, respectively. The mononuclear uranium- containing complexes in the crystals of U(IV) and U(VI) perchlorates were found to obey the 14 neighbors rule.

1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled β-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes.

PubMed

Ansari, Mohd Asif; Mandal, Abhishek; Paretzki, Alexa; Beyer, Katharina; Fiedler, Jan; Kaim, Wolfgang; Lahiri, Goutam Kumar

2016-06-06

The dinuclear complexes {(μ-H2L)[Ru(bpy)2]2}(ClO4)2 ([3](ClO4)2), {(μ-H2L)[Ru(pap)2]2}(ClO4)2 ([4](ClO4)2), and the asymmetric [(bpy)2Ru(μ-H2L)Ru(pap)2](ClO4)2 ([5](ClO4)2) were synthesized via the mononuclear species [Ru(H3L)(bpy)2]ClO4 ([1]ClO4) and [Ru(H3L)(pap)2]ClO4 ([2]ClO4), where H4L is the centrosymmetric 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochemistry of the structurally characterized [1]ClO4, [2]ClO4, [3](ClO4)2, [4](ClO4)2, and [5](ClO4)2 reveals multistep oxidation and reduction processes, which were analyzed by electron paramagnetic resonance (EPR) of paramagnetic intermediates and by UV-vis-NIR spectro-electrochemistry. With support by time-dependent density functional theory (DFT) calculations the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 3(3+) versus largely bridge-centered spin in 4(3+)-a result of the presence of Ru(II)-stabilizig pap coligands. In addition to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asymmetric system 5(3+) with about equal contributions from a radical bridge formulation. In comparison to the analogues with the deprotonated 1,4-diaminoanthraquinone isomer the centrosymmetric H2L(2-) bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites.

Trinuclear Lanthanoid Complexes of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol with a Unique, Sandwich-Type Cage Structure(1).

PubMed

Hedinger, Roman; Ghisletta, Michele; Hegetschweiler, Kaspar; Tóth, Eva; Merbach, André E.; Sessoli, Roberta; Gatteschi, Dante; Gramlich, Volker

1998-12-28

A variety of trinuclear complexes [M(3)(H(-)(3)L)(2)](3+) [M = Y, La, Eu, Gd, Dy; L = 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) and 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (tdci)] was prepared as solid materials of the composition M(3)(H(-)(3)L)(2)X(3).pH(2)O.qEtOH (X = Cl, NO(3); 2.5

Linear Free Energy Relationships in Dinuclear Compounds. 2. Inductive Redox Tuning via Remote Substituents in Quadruply Bonded Dimolybdenum Compounds.

PubMed

Lin, Chun; Protasiewicz, John D.; Smith, Eugene T.; Ren, Tong

1996-10-23

Syntheses and characterizations are reported for dimolybdenum(II) compounds supported by the diarylformamidinate (ArNC(H)NAr(-)) ligand, where Ar is XC(6)H(4)(-), with X as p-OMe (1), H (2), m-OMe (3), p-Cl (4), m-Cl (5), m-CF(3) (6), p-COMe (7), p-CF(3) (8), or Ar is 3,4-Cl(2)C(6)H(3)(-) (9) or 3,5-Cl(2)C(6)H(3)(-) (10). The (quasi)reversible oxidation potentials measured for the Mo(2)(5+)/Mo(2)(4+) couple were found to correlate with the Hammett constant (sigma(X)) of the aryl substituents according to the following equation: DeltaE(1/2) = E(1/2)(X) - E(1/2)(H) = 87(8sigma(X)) mV. Molecular structure determinations of compounds 1, 2, 5, and 10 revealed an invariant core geometry around the Mo(2) center, with statistically identical Mo-Mo quadruple bond lengths of 2.0964(5), 2.0949[8], 2.0958(6), and 2.0965(5) Å, respectively. Magnetic anisotropies for compounds 1-10 estimated on the basis of (1)H NMR data were similar and unrelated to sigma(X). Similarity in UV-vis spectra was also found within the series, which, in conjunction with the features of both molecular structures and (1)H NMR spectra, was interpreted as the existence of a constant upper valence structure across the series. Results of Fenske-Hall calculations performed for several model compounds paralleled the experimental observations.

Di-tert-butyl­chlorido(N,N-dibenzyl­dithio­carbamato)tin(IV)

PubMed Central

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R. T.

2011-01-01

The SnIV atom in the title diorganotin dithio­carbamate, [Sn(C4H9)2(C15H14NS2)Cl], is penta­coordinated by an asymmetrically coordinating dithio­carbamate ligand, a Cl atom and two C atoms of the Sn-bound tert-butyl groups. The resulting C2ClS2 donor set defines a coordination geometry inter­mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. PMID:21522304

High Color Rendering Index White-Light Emission from UV-Driven LEDs Based on Single Luminescent Materials: Two-Dimensional Perovskites (C6H5C2H4NH3)2PbBr xCl4- x.

PubMed

Yang, Shuming; Lin, Zhenghuan; Wang, Jingwei; Chen, Yunxiang; Liu, Zhengde; Yang, E; Zhang, Jian; Ling, Qidan

2018-05-09

Two-dimensional (2D) white-light-emitting hybrid perovskites (WHPs) are promising active materials for single-component white-light-emitting diodes (WLEDs) driven by UV. However, the reported WHPs exhibit low quantum yields (≤9%) and low color rendering index (CRI) values less than 85, which does not satisfy the demand of solid-state lighting applications. In this work, we report a series of mixed-halide 2D layered WHPs (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr x Cl 4- x (0 < x < 4) obtained from the phenethylammonium cation. Unlike the reported WHPs including (C 6 H 5 C 2 H 4 NH 3 ) 2 PbCl 4 , the mixed-halide perovskites display morphology-dependent white emission for the different extents of self-absorption. Additionally, the amount of Br has a huge influence on the photophysical properties of mixed-halide WHPs. With the increasing content of Br, the quantum yields of WHPs increase gradually from 0.2 to 16.9%, accompanied by tunable color temperatures ranging from 4000 K ("warm" white light) to 7000 K ("cold" white light). When applied to the WLEDs, the mixed-halide perovskite powders exhibit tunable white electroluminescent emission with very high CRI of 87-91.

Synthetic and Spectroscopic Studies on N-(i,j-Disubstituted Phenyl)-4- Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i, j = 2, 3; 2, 4; 2, 5; 2, 6 or 3, 4; and X = CH3 or Cl

NASA Astrophysics Data System (ADS)

Shetty, Mahesha; Gowda, B. Thimme

2005-02-01

Fifty four N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides of the general formula 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i,j = 2,3; 2,4; 2,5; 2,6 or 3, 4; and X = CH3 or Cl, are prepared and characterized and their infrared, 1H and 13C NMR spectra in solution are studied. The N-H stretching vibrations νN-H absorb in the range 3305 - 3205 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1377 - 1307 cm-1 and 1184 - 1128 cm-1, respectively. The N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides show C-S, S-N and C-N stretching vibrations in the ranges 844 - 800 cm-1, 945 - 891 cm-1 and 1309 - 1170 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbon atoms of the two benzene rings. Incremental shifts of the ring protons and carbon atoms due to -SO2NH(i,j-X2C6H3) groups in C6H5SO2NH(i,j-X2C6H3) and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H*) are computed and employed to calculate the chemical shifts of the ring protons and carbon atoms in the substituted compounds 4-X'C6H4SO2NH(i,j-X2C6H3). The different methods of calculation lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating the validity of the principle of additivity of the substituent effects with chemical shifts in these compounds.

Geochemical evidence for the existence of high-temperature hydrothermal brines at Vesuvio volcano, Italy

NASA Astrophysics Data System (ADS)

Chiodini, Giovanni; Marini, Luigi; Russo, Massimo

2001-07-01

A high-temperature hydrothermal system is present underneath the crater area of Vesuvio volcano. It is suggested that NaCl brines reside in the high-temperature reservoir and influence the chemical composition of the gases discharged by the fumaroles of the crater bottom (vents FC1, FC2, and FC5). These have typical hydrothermal compositions, with H 2O and CO 2 as major components, followed by H 2, H 2S, N 2, CH 4, and CO (in order of decreasing contents) and undetectable SO 2, HCl, and HF. Fumarolic H 2O is either meteoric water enriched in 18O through high-temperature water-rock oxygen isotope exchange or a mixture of meteoric and arc-type magmatic water. Fumarolic CO 2 is mainly generated by decarbonation reactions of marine carbonates, but the addition of small amounts of magmatic CO 2 is also possible. All investigated gas species (H 2O, CO 2, CO, CH 4, H 2, H 2S, N 2, and NH 3) equilibrate, probably in a saturated vapor phase, at temperatures of 360 to 370°C for vent FC1 and 430 to 445°C for vents FC2 and FC5. These temperatures are confirmed by the H 2-Ar geoindicator. The minimum salt content of the liquid phase coexisting with the vapor phase is ˜14.9 wt.% NaCl, whereas its maximum salinity corresponds to halite saturation (49.2-52.5 wt.% NaCl). These poorly constrained salinities of NaCl brines reflect in large uncertainties in total fluid pressures, which are estimated to be 260 to 480 bar for vents FC2 and FC5 and 130 to 220 bar for vent FC1. Pressurization in some parts of the hydrothermal system, and its subsequent discharge through hydrofracturing, could explain the relatively frequent seismic crises recorded in the Vesuvio area after the last eruption. An important heat source responsible for hydrothermal circulation is represented by the hot rocks of the eruptive conduits, which have been active from 1631 to 1944. Geochemical evidence suggests that no input of fresh magma at shallow depths took place after the end of the last eruptive period.

Mixed-Substituent Cyclophosphazenes with Calamitic and Polycatenar Mesogens.

PubMed

Jiménez, J; Callizo, L; Serrano, J L; Barberá, J; Oriol, L

2017-07-17

A synthetic strategy has been developed to prepare liquid crystalline cyclotriphosphazenes that have two different types of mesogenic units linked to the same phosphorus atom. Hexachlorocyclotriphosphazene, N 3 P 3 Cl 6 , was reacted with 3 mol of the calamitic unit 4-cyano-4'-hydroxybiphenyl to give a mixture of compounds in which the nongem-trans-trisubstituted derivative N 3 P 3 Cl 3 (OC 6 H 4 C 6 H 4 {CN}-p) 3 was the major product. The substitution of all three chlorine atoms in this nongeminal compound gave rise to the hydroxyl-functional phosphazenes, nongem-trans-N 3 P 3 (OC 6 H 4 C 6 H 4 {CN}-p) 3 (OC 6 H 4 {OH}-p) 3 or nongem-trans-N 3 P 3 (OC 6 H 4 C 6 H 4 {CH 3 }-p) 3 (OC 6 H 4 {OH}-p) 3 , from which the second mesogenic unit, a polycatenar one, was introduced. The chemical structure of the resulting materials, deduced from spectroscopic and MALDI-TOF techniques, was in accordance with monodisperse, fully functionalized cyclotriphosphazenes. Mesomorphism is highly dependent on the terminal group of the calamitic units, and liquid crystal phases were only detected on the cyano-derivatives. The calamitic or columnar nature of the mesophase depends on the number of alkyl chains of the polycatenar moieties.

Surface tensions of inorganic multicomponent aqueous electrolyte solutions and melts.

PubMed

Dutcher, Cari S; Wexler, Anthony S; Clegg, Simon L

2010-11-25

A semiempirical model is presented that predicts surface tensions (σ) of aqueous electrolyte solutions and their mixtures, for concentrations ranging from infinitely dilute solution to molten salt. The model requires, at most, only two temperature-dependent terms to represent surface tensions of either pure aqueous solutions, or aqueous or molten mixtures, over the entire composition range. A relationship was found for the coefficients of the equation σ = c(1) + c(2)T (where T (K) is temperature) for molten salts in terms of ion valency and radius, melting temperature, and salt molar volume. Hypothetical liquid surface tensions can thus be estimated for electrolytes for which there are no data, or which do not exist in molten form. Surface tensions of molten (single) salts, when extrapolated to normal temperatures, were found to be consistent with data for aqueous solutions. This allowed surface tensions of very concentrated, supersaturated, aqueous solutions to be estimated. The model has been applied to the following single electrolytes over the entire concentration range, using data for aqueous solutions over the temperature range 233-523 K, and extrapolated surface tensions of molten salts and pure liquid electrolytes: HCl, HNO(3), H(2)SO(4), NaCl, NaNO(3), Na(2)SO(4), NaHSO(4), Na(2)CO(3), NaHCO(3), NaOH, NH(4)Cl, NH(4)NO(3), (NH(4))(2)SO(4), NH(4)HCO(3), NH(4)OH, KCl, KNO(3), K(2)SO(4), K(2)CO(3), KHCO(3), KOH, CaCl(2), Ca(NO(3))(2), MgCl(2), Mg(NO(3))(2), and MgSO(4). The average absolute percentage error between calculated and experimental surface tensions is 0.80% (for 2389 data points). The model extrapolates smoothly to temperatures as low as 150 K. Also, the model successfully predicts surface tensions of ternary aqueous mixtures; the effect of salt-salt interactions in these calculations was explored.

Thermodynamics of concentrated electrolyte mixtures and the prediction of mineral solubilities to high temperatures for mixtures in the system Na-K-Mg-Cl-SO 4-OH-H 2O

NASA Astrophysics Data System (ADS)

Pabalan, Roberto T.; Pitzer, Kenneth S.

1987-09-01

Mineral solubilities in binary and ternary electrolyte mixtures in the system Na-K-Mg-Cl-SO 4-OH-H 2O are calculated to high temperatures using available thermodynamic data for solids and for aqueous electrolyte solutions. Activity and osmotic coefficients are derived from the ion-interaction model of Pitzer (1973, 1979) and co-workers, the parameters of which are evaluated from experimentally determined solution properties or from solubility data in binary and ternary mixtures. Excellent to good agreement with experimental solubilities for binary and ternary mixtures indicate that the model can be successfully used to predict mineral-solution equilibria to high temperatures. Although there are currently no theoretical forms for the temperature dependencies of the various model parameters, the solubility data in ternary mixtures can be adequately represented by constant values of the mixing term θ ij and values of ψ ijk which are either constant or have a simple temperature dependence. Since no additional parameters are needed to describe the thermodynamic properties of more complex electrolyte mixtures, the calculations can be extended to equilibrium studies relevant to natural systems. Examples of predicted solubilities are given for the quaternary system NaCl-KCl-MgCl 2-H 2O.

Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane.

PubMed

Han, Xue; Ke, Jie; Suleiman, Norhidayah; Levason, William; Pugh, David; Zhang, Wenjian; Reid, Gillian; Licence, Peter; George, Michael W

2016-06-07

We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

Low Temperature Fluorination of Aerosol and Condensed Phase Sol Suspensions of Hydrocarbons Utilizing Elemental Fluorine.

DTIC Science & Technology

1980-04-01

subambient temperature capability of our design . The aerosol fluorination system designed to produce a controlled , con- tinuous stream of aerosol...F3 H8 , 117 (68.9) C6F2H7 CN: D I Mixture CO: D I’’ Difluorocyclohexane Isomer (two nonequivalent CFR groups ) 1 H NMR no integration given 1 9F NMR: d...two nonequivalent CFH groups ) 1H NMR no integration given 19F NMR d? at 193.5 ppm (J = 106.8 Rz ?) 32 TABLE 7 (CONTINUED) MS: CI: 119 (1.4) C6F2

Calculation of the Standard Molal Thermodynamic Properties of Crystalline, Liquid, and Gas Organic Molecules at High Temperatures and Pressures

NASA Astrophysics Data System (ADS)

Helgeson, Harold C.; Owens, Christine E.; Knox, Annette M.; Richard, Laurent

1998-03-01

Calculation of the thermodynamic properties of organic solids, liquids, and gases at high temperatures and pressures is a requisite for characterizing hydrothermal metastable equilibrium states involving these species and quantifying the chemical affinities of irreversible reactions of organic molecules in natural gas, crude oil, kerogen, and coal with minerals and organic, inorganic, and biomolecular aqueous species in interstitial waters in sedimentary basins. To facilitate calculations of this kind, coefficients for the Parameters From Group Contributions (PFGC) equation of state have been compiled for a variety of groups in organic liquids and gases. In addition, molecular weights, critical temperatures and pressures, densities at 25°C and 1 bar, transition, melting, and boiling temperatures ( Tt,Pr, Tm,Pr, and Tv,Pr, respectively) and standard molal enthalpies of transition (Δ H° t,Pr), melting (Δ H° m,Pr), and vaporization (Δ H° v,Pr) of organic species at 1 bar ( Pr) have been tabulated, together with an internally consistent and comprehensive set of standard molal Gibbs free energies and enthalpies of formation from the elements in their stable state at 298.15 K ( Tr) and Pr (Δ G° f and Δ H° f, respectively). The critical compilation also includes standard molal entropies ( S°) and volumes ( V°) at Tr and Pr, and standard molal heat capacity power function coefficients to compute the standard molal thermodynamic properties of organic solids, liquids, and gases as a function of temperature at 1 bar. These properties and coefficients have been tabulated for more than 500 crystalline solids, liquids, and gases, and those for many more can be computed from the equations of state group additivity algorithms. The crystalline species correspond to normal alkanes (C nH 2( n+1) ) with carbon numbers ( n, which is equal to the number of moles of carbon atoms in one mole of the species) ranging from 5 to 100, and 23 amino acids including glycine (C 2H 5NO 2), alanine (C 3H 7NO 2), valine (C 5H 11NO 2), leucine (C 6H 13NO 2), isoleucine (C 6H 13NO 2), aspartic acid (C 4H 7NO 4), glutamic acid (C 5H 9NO 4), asparagine (C 4H 8N 2O 3), glutamine (C 5H 10N 2O 3), proline (C 5H 9NO 2), phenylalanine (C 9H 11NO 2), tryptophan (C 11H 12N 2O 2), methionine (C 5H 11SNO 2), serine (C 3H 7NO 3), threonine (C 4H 9NO 3), cysteine (C 3H 7SNO 2), tyrosine (C 9H 11NO 3), lysine (C 6H 14N 2O 2), lysine:HCl (C 6H 15N 2O 2Cl), arginine (C 6H 14N 4O 2), arginine:HCl (C 6H 15N 4O 2Cl), histidine (C 6H 9N 3O 2), and histidine:HCl (C 6H 10N 3O 2Cl). The data for the latter compounds permit calculation of the standard molal thermodynamic properties of protein unfolding in biogeochemical processes (Helgeson et al 1998). The liquids and gases considered in the present study include normal alkanes (C nH 2( n+1) ) for carbon numbers ranging from 1 to 100, 2- and 3-methylalkanes (C nH 2( n+1) ) for 4 ≤ n ≤ 20 and 6 ≤ n ≤ 20, respectively, 2,3-dimethylpentane (C 7H 16), 4-methylheptane (C 8H 18), cycloalkanes (C nH 2 n) for 3 ≤ n ≤ 8, methylated benzenes (C nH 2( n-3) ) for 7 ≤ n ≤ 12, normal alkylbenzenes (C nH 2( n-3) ) for 6 ≤ n ≤ 20, normal 1-alcohols (C nH 2( n+1) O) for 1 ≤ n ≤ 20, ethylene glycol (C 2H 6O 2), glycerol (C 3H 8O 3), normal 1-alkanethiols (C nH 2( n+1) S) for 1 ≤ n ≤ 20, normal carboxylic acids (C nH 2 nO 2) for 2 ≤ n ≤ 20, and the following miscellaneous species: 2-thiabutane (C 3H 8S), thiophene (C 4H 4S), thiophenol (C 6H 6S), acetone (C 3H 6O), 2-butanone (C 4H 8O), ethyl acetate (C 4H 8O 2), pyridine (C 5H 5N), 3-methylpyridine (C 6H 7N), and quinoline (C 9H 7N). One additional liquid (2-methylthiacyclopentane (C 5H 10S)) was also considered along with crystalline and gaseous carbazole (C 12H 9N). The thermodynamic data and equations summarized below can be used together with the standard molal thermodynamic properties of high molecular weight organic compounds ( Richard and Helgeson 1995, Richard and Helgeson 1998a, Richard and Helgeson 1998b) and minerals, inorganic gases, and aqueous species, including biomolecules ( Johnson et al 1992; Shock 1992a, Shock 1994, Shock 1995; Shock et al 1997; Shock and Koretsky 1993, Shock and Koretsky 1995; Sassani and Shock 1992, Sassani and Shock 1994; Schulte and Shock 1993, Schulte and Shock 1995; Oelkers et al 1995; Amend and Helgeson 1997a, Amend and Helgeson 1997b, Amend and Helgeson 1997c, Amend and Helgeson 1998; Sverjensky et al 1997) to compute equilibrium constants and chemical affinities for a wide variety of organic-inorganic reactions in geochemical and biochemical processes at both high and low temperatures and pressures. Unless indicated otherwise, all amino acid designations in the present communication refer to the L-α form.

Vapor-liquid phase equilibria of potassium chloride-water mixtures: Equation-of-state representation for KCl-H2O and NaCl-H2O

USGS Publications Warehouse

Hovey, J.K.; Pitzer, Kenneth S.; Tanger, J.C.; Bischoff, J.L.; Rosenbauer, R.J.

1990-01-01

Measurements of isothermal vapor-liquid compositions for KCl-H2O as a function of pressure are reported. An equation of state, which was originally proposed by Pitzer and was improved and used by Tanger and Pitzer to fit the vapor-liquid coexistence surface for NaCl-H2O, has been used for representation of the KCl-H2O system from 300 to 410??C. Improved parameters are also reported for NaCl-H2O from 300 to 500??C. ?? 1990 American Chemical Society.

Homoleptic versus Heteroleptic Formation of Mononuclear Fe(II) Complexes with Tris-Imine Ligands

DOE PAGES

Barrios, Leoni A.; Bartual-Murgui, Carlos; Peyrecave-Lleixa, Eugenia; ...

2016-04-13

In this paper, we show a marked tendency of Fe(II) to form heteroleptic [Fe(L)(L')](ClO 4) 2 complexes from pairs of chelating tris-imine 3bpp, tpy, or 2bbp ligands. New synthetic avenues for spin crossover research become thus available, here illustrated with three new heteroleptic compounds with differing magnetic behaviors: [Fe(H 4L1)(Cl-tpy)](ClO 4) 2 ·C 3H 6O (1), [Fe(H 2L3)(Me3bpp)](ClO 4) 2 ·C 3H 6O (2), [Fe(H 4L1)(2bbp)](ClO 4) 2 ·3C 3H 6O (3). Structural studies demonstrate that 1 is in the low-spin (LS) state up to 350 K, while complexes 2 and 3 are, by contrast, in the high-spin (HS) statemore » down to 2 K, as corroborated through magnetic susceptibility measurements. Upon exposure to the atmosphere, the latter exhibits the release of three molecules of acetone per complex, turning into the solvent-free analogue [Fe(H 4L1)(2bbp)](ClO 4) 2 (3a), through a single-crystal-to-single-crystal transformation. Lastly, this guest extrusion process is accompanied by a spin switch, from HS to LS.« less

Synthesis and some coordination chemistry of the PSnP pincer-type stannylene Sn(NCH2PtBu2)2C6H4, attempts to prepare the PSiP analogue, and the effect of the E atom on the molecular structures of E(NCH2PtBu2)2C6H4 (E = C, Si, Ge, Sn).

PubMed

Brugos, Javier; Cabeza, Javier A; García-Álvarez, Pablo; Pérez-Carreño, Enrique; Polo, Diego

2018-03-26

The non-donor-stabilized PSnP pincer-type stannylene Sn(NCH2PtBu2)2C6H4 (1) has been prepared by treating SnCl2 with Li2(NCH2PtBu2)2C6H4. All attempts to synthesize the analogous PSiP silylene by reduction of the (previously unknown) silanes SiCl2(NCH2PtBu2)2C6H4 (2), SiHCl(NCH2PtBu2)2C6H4 (3) and SiH(HMDS)(NCH2PtBu2)2C6H4 (4; HMDS = N(SiMe3)2) have been unsuccessful. The almost planar (excluding the tert-butyl groups) molecular structure of stannylene 1 (determined by X-ray crystallography) has been rationalized with the help of DFT calculations, which have shown that, in the series of diphosphanetetrylenes E(NCH2PtBu2)2C6H4 (E = C, Si, Ge, Sn), the most stable conformation of the compounds with E = Ge and Sn has both P atoms very close to the EN2C6H4 plane, near (interacting with) the E atom, whereas for the compounds with E = C and Si, both phosphane groups are located at one side of the EN2C6H4 plane and far away from the E atom. The size of the E atom and the strength of stabilizing donor-acceptor PE interactions (both increase on going down in group 14) are key factors in determining the molecular structures of these diphosphanetetrylenes. The syntheses of the chloridostannyl complexes [Rh{κ2Sn,P-SnCl(NCH2PtBu2)2C6H4}(η4-cod)] (5), [RuCl{κ2Sn,P-SnCl(NCH2PtBu2)2C6H4}(η6-cym)] (6) and [IrCl{κ2Sn,P-SnCl(NCH2PtBu2)2C6H4}(η5-C5Me5)] (7) have demonstrated the tendency of stannylene 1 to insert its Sn atom into M-Cl bonds of transition metal complexes and the preference of the resulting PSnP chloridostannyl group to act as a κ2Sn,P-chelating ligand, maintaining an uncoordinated phosphane fragment. X-ray diffraction data (of 6), 31P{1H} NMR data (of 5-7) and DFT calculations (on 6) are consistent with the existence of a weak PSn interaction involving the non-coordinated P atom of complexes 5-7, similar to that found in stannylene 1.

Isomorphous rare-earth bis[bis(2,6-diisopropylphenyl)phosphate] complexes and their self-assembly into two-dimensional frameworks by intramolecular hydrogen bonds.

PubMed

Minyaev, Mikhail E; Nifant'ev, Ilya E; Tavtorkin, Alexander N; Korchagina, Sof'ya A; Zeynalova, Shadana Sh; Ananyev, Ivan V; Churakov, Andrei V

2017-10-01

The crystal structures of rare-earth diaryl- or dialkylphosphate derivatives are poorly explored. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]chloridotetrakis(methanol-κO)neodymium methanol disolvate, [Nd(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (1), and of the lutetium, [Lu(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (2), and yttrium, [Y(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (3), analogues have been obtained by reactions between lithium bis(2,6-diisopropylphenyl)phosphate and LnCl 3 (H 2 O) 6 (in a 2:1 ratio) in methanol. Compounds (1)-(3) crystallize in the C2/c space group. Their crystal structures are isomorphous. The molecule possesses C 2 symmetry with a twofold crystallographic axis passing through the Ln and Cl atoms. The bis(2,6-diisopropylphenyl)phosphate ligands all display a κ 1 O-monodentate coordination mode. The coordination polyhedron for the metal atom [coordination number (CN) = 7] is a distorted pentagonal bipyramid. Each [Ln{O 2 P(O-2,6- i Pr 2 C 6 H 3 ) 2 } 2 Cl(CH 3 OH) 4 ] molecular unit exhibits two intramolecular O-H...O hydrogen bonds, forming six-membered rings, and two intramolecular O-H...Cl interactions, forming four-membered rings. Intermolecular O-H...O hydrogen bonds connect each unit via four noncoordinating methanol molecules with four other units, forming a two-dimensional hydrogen-bond network. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]tetrakis(methanol-κO)(nitrato-κ 2 O,O')neodymium methanol disolvate, [Nd(C 24 H 34 O 4 P)(NO 3 )(CH 4 O) 4 ]·2CH 3 OH, (4), have been obtained in an analogous manner from NdCl 3 (H 2 O) 6 . Compound (4) also crystalizes in the C2/c space group. Its crystal structure is similar to those of (1)-(3). The κ 2 O,O'-bidentate nitrate anion is disordered over a twofold axis, being located nearly on it. Half of the molecule is crystallographically unique (CN Nd = 8). Unlike (1)-(3), complex (4) exhibits disorder of all three methanol molecules, one isopropyl group of the phosphate ligand and the NO 3 - ligand. The structure of (4) displays intra- and intermolecular O-H...O hydrogen bonds similar to those in (1)-(3). Compounds (1)-(4) represent the first reported mononuclear bis[bis(diaryl/dialkyl)phosphate] rare-earth complexes.

Pyrolysis of polyolefins for increasing the yield of monomers' recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donaj, Pawel J., E-mail: pawel@mse.kth.se; Kaminsky, W.; Buzeto, F.

2012-05-15

Highlights: Black-Right-Pointing-Pointer Thermal and catalytic pyrolysis of mixed polyolefins in fluidized bed has been studied. Black-Right-Pointing-Pointer We tested applicability of a commercial Ziegler-Natta catalyst (Z-N: TiCl{sub 4}/MgCl{sub 2}). Black-Right-Pointing-Pointer The catalyst has a strong influence on product distribution, increasing gas fraction. Black-Right-Pointing-Pointer At 650 Degree-Sign C the monomer generation increased by 55% when the catalyst was used. Black-Right-Pointing-Pointer We showed the concept of treatment of mixed polyolefins without a need of separation. - Abstract: Pyrolysis of plastic waste is an alternative way of plastic recovery and could be a potential solution for the increasing stream of solid waste. The objectivemore » of this work was to increase the yield the gaseous olefins (monomers) as feedstock for polymerization process and to test the applicability of a commercial Ziegler-Natta (Z-N): TiCl{sub 4}/MgCl{sub 2} for cracking a mixture of polyolefins consisted of 46% wt. of low density polyethylene (LDPE), 30% wt. of high density polyethylene (HDPE) and 24% wt. of polypropylene (PP). Two sets of experiments have been carried out at 500 and 650 Degree-Sign C via catalytic pyrolysis (1% of Z-N catalyst) and at 650 and 730 Degree-Sign C via only-thermal pyrolysis. These experiments have been conducted in a lab-scale, fluidized quartz-bed reactor of a capacity of 1-3 kg/h at Hamburg University. The results revealed a strong influence of temperature and presence of catalyst on the product distribution. The ratios of gas/liquid/solid mass fractions via thermal pyrolysis were: 36.9/48.4/15.7% wt. and 42.4/44.7/13.9% wt. at 650 and 730 Degree-Sign C while via catalytic pyrolysis were: 6.5/89.0/4.5% wt. and 54.3/41.9/3.8% wt. at 500 and 650 Degree-Sign C, respectively. At 650 Degree-Sign C the monomer generation increased by 55% up to 23.6% wt. of total pyrolysis products distribution while the catalyst was added. Obtained yields of olefins were compared with the naphtha steam cracking process and other potentially attractive processes for feedstock generation. The concept of closed cycle material flow for polyolefins has been discussed, showing the potential benefits of feedstock recycling in a plastic waste management.« less

Marinobacterium rhizophilum sp. nov., isolated from the rhizosphere of the coastal tidal-flat plant Suaeda japonica.

PubMed

Kim, Yoon-Gon; Jin, Yeon-A; Hwang, Chung Yeon; Cho, Byung Cheol

2008-01-01

A Gram-negative, strictly aerobic, marine bacterium, designated strain CL-YJ9(T), was isolated from sediment closely associated with the roots of a plant (Suaeda japonica) inhabiting a coastal tidal flat. Cells of the novel strain were straight and rod-shaped and were motile by means of monopolar flagella. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CL-YJ9(T) belongs to the genus Marinobacterium and was most closely related to Marinobacterium halophilum mano11(T) (94.1% sequence similarity) and to other members of the genus Marinobacterium (92.5-93.7% sequence similarity). The strain grew with 1-5% NaCl (optimum, 3%) and at 5-30 degrees C (optimum, approx. 25 degrees C) and pH 6.0-9.0 (optimum, pH 7.0). The predominant cellular fatty acids were summed feature 3 (C(16:1)omega7c and/or iso-C(15:0) 2-OH, 40.3%), C(18:1)omega7c (26.6%), C(16:0) (16.6%) and C(10:0) 3-OH (7.1%). The major isoprenoid quinone was Q-8. The G+C content of the genomic DNA was 61 mol%. On the basis of the data from this polyphasic study, strain CL-YJ9(T) belongs to the genus Marinobacterium but is distinguishable from the recognized species. Strain CL-YJ9(T) therefore represents a novel species, for which the name Marinobacterium rhizophilum sp. nov. is proposed. The type strain is CL-YJ9(T) (=KCCM 42386(T) =DSM 18822(T)).

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place. Part 3. (Beachy Lumber Co.-Campanova, Richard MD)

DTIC Science & Technology

1989-01-01

34ᝰ >w 00 C In --4 C4 -ONN4r- N0-0 11 a M-0 cg< i 1.10 -4 l 9 1 L go ~t00 -40 B LA. ZEZ Z Z Z Z Z Z Z ZZ Z L to01000 z 2 Z0ZZZZZZZZ, (00~t II0. O)41...00 0) 0) 07 ’) n N0) C) 0) 44r- 0 M’ U.n U dw01 44 I -4 000 0OC 0D 0 00 0 0 Is4 ( 9 O J WIn 114IC tax H UJ WC) :14 H WCJ 44 2Z2 2 Z 22 z Z z H 000 4’ M0...4 -4-4 m -4 .- 4 .- 4 -4 -4 -4 -4 -4 404 4- 4W 0000 WWWWWW C(((0000(( u0 N - (0 ) -0)0) 0000 ~--CL If to I 0000 W 4 00000000to "D 00 MC0 -4 .- 4 . 9

Ion Pair Formation between Tertiary Aliphatic Amines and Perchlorate in the Biphasic Water/Dichloromethane System.

PubMed

Badocco, Denis; Di Marco, Valerio; Venzo, Alfonso; Frasconi, Marco; Frezzato, Diego; Pastore, Paolo

2017-10-12

The ability of aliphatic amines (AAs), namely, tripropylamine (TPrA), trisobutylamine (TisoBuA), and tributylamine (TBuA), to form ion pairs with perchlorate anion (ClO 4 - ) in biphasic aqueous/dichloromethane (CH 2 Cl 2 ) mixtures containing ClO 4 - 0.1 M has been demonstrated by GC with flame ionization (FID) and mass detectors (MS) and by NMR measurements. The extraction efficiency of the AAs to the organic phase was modeled by equations that were used to fit the experimental GC data, allowing us to determine values for K P (partition constant of the free AA), K IP (formation constant of the ion pair), and K P IP (partition constant of the ion pair) for TPrA, TisoBuA, and TBuA at 25 °C. Ion pairs were shown to form in CH 2 Cl 2 also when ClO 4 - is replaced by other inorganic anions, like NO 3 - , ClO 3 - , Cl - , H 2 PO 4 - , and IO 3 - . No ion pairs formed when CH 2 Cl 2 was replaced by n-hexane, suggesting that aliphatic amine ion pairs can form in polar organic solvents but not in nonpolar ones.

Influence of pH and ionic strength (NaCl/Na2SO4) on the reaction HO Cl/ClO- + NO2-

NASA Astrophysics Data System (ADS)

Marcellos da Rosa, M.; Zetzsch, C.

2003-04-01

Equilibria such as HOCl + NO_2^- leftrightarrow ClNO_2 + OH^- and ClNO_2 + H_2O leftrightarrow NO_3^- + 2H^+ + Cl^- play an important role in halogen activation in the troposphere. We studied the oxidation of NO_2^- by HOCl/ClO^- in aqueous phase by stopped-flow measurements at different ionic strengths (bidestilled water, 0.1M NaCl, 1.0M NaCl and 1.0M Na_2SO^4) at various pH values (4.0, 5.5, 6.2 and 10.0) at 293K. The experiments were performed using a SX.18MV Applied Photophysics spectrophotometer, observing the exponential decay of HOCl/ClO^- at λ = 290nm between 10ms and 100s. HOCl (pK_a= 7.50) was obtained by bubbling N_2 with 1% Cl_2 through bidestilled water. The pH of the aqueous solutions of HOCl was determined by a pH meter (CG820, Schott) with a glass electrode N6180 (calibrated with standard buffer solutions at pH = 3.0, 4.0, 7.0 and 10.0), and the pH values were adjusted by dropwise addition of HClO_4 or NaOH. The concentrations of HOCl (ɛHOCl (230nm) = 100M-1cm-1) ([HOCl] = 1.3mM - 10mM) and ClO- (ɛClO- (292nm) = 350 M-1cm-1) ([ClO^-] = 1.3mM - 5mM) were determined by UV spectrometry (Kontron UVIKON 860) at a resolution of 2 nm in 1 cm cells at various pH values. The concentration range of NO_2^- was between 5mM and 50mM. The following second-order rate constant kII were obtained at 293K at various pH values (in units of M-1s-1) in H_2O: pH 4.0, (5.6±0.3)\\cdot 10^3; pH 5.5, (5.0±0.4)\\cdot 10^3; pH 10.0, 3.9±0.4; in 0.1M NaCl: pH 5.5, (4.3±0.4)\\cdot 10^3; pH 10.0, 2.6±0.4; in 1.0M NaCl: pH 5.5, (4.0±0.3); pH 10.0, 0.7±0.2 and in 1.0M Na_2SO_4: pH 5.5, (3.0±0.3)\\cdot 10^3; pH 10.0, 1.9±0.4. There is a strong effect of the pH on the reaction HOCl/ClO^- + NO_2^-, as reflected in the ratio kII_a(pH 5.5, HOCl)/kII_b(pH 10.0, ClO^-): in H_2O (kII_a ˜ 1200 \\cdot kII_b), in 0.1M NaCl (kII_a ˜ 1900 \\cdot kII_b), in 1.0M NaCl (kII_a ˜ 5700 \\cdot kII_b) and in 1.0 M Na_2SO_4 (kII_a ˜ 1500 \\cdot kII_b). A mechanism for the oxidation of NO_2^- by HOCl/ClO^- will be presented and compared with previous work.

Local environment around gold (III) in aqueous chloride solutions: An EXAFS spectroscopy study

NASA Astrophysics Data System (ADS)

Farges, Franã§Ois; Sharps, Julia A.; Brown, Gordon E., Jr.

1993-03-01

The local environment around Au (III) in aqueous solutions containing 1 M NaCl was determined as a function of pH and Au concentration using X-ray absorption spectroscopy (XAS) at ambient temperature and pressure. The solution Au concentrations studied were 10 - to 10 -3 M and the pH ranged between 2 and 9.2. No significant changes of Au speciation were detected with increasing Au concentration; however, major speciation changes were caused by variations in pH. At pH = 2, Au is coordinated by four Cl atoms ( mean d [AuCl] = 2.28 -2.29 ± 0.01 Å), whereas at pH 7.5 and 9.2, Au is coordinated by three Cl and one O (or OH) and by two Cl and two O (or OH), respectively ( mean d[AuCl] = 2.28 ± 0.02 Å; mean d[AuO or AuOH] = 1.97 ± 0.02 Å), indicating replacement of Cl by O (or OH) with increasing pH. In all solutions studied, the number of first-neighbors around Au(III) is close to four. XANES analysis suggests the presence of a square-planar geometry for AuX 4 ( X = Cl, O) at all pH values studied. These results are in excellent agreement with those from our previous Raman, resonance Raman, and UV/visible spectroscopy study of gold(III)-chloride solutions (PECK et al., 1991), which found that AuCl 4-, AuCl 3(OH) -, and AuCl 2(OH) 2- are the majority species in the pH ranges 2-6, 6-8.5, and 8.5-11, respectively. We did not find evidence for Au(I)Cl 2- or Au(I)Cl(OH) - complexes in our pH 7.5 and 9.2 solutions, as was recently suggested by PAN and WOOD (1991) for acidic gold chloride solutions at temperatures > 100°C, although we can't rule these complexes out as minority species (<10% of the total Au in solution). Our EXAFS results also provide the first direct evidence for Cl second neighbors around AuCl 4- complexes in the most acidic solutions studied ( pH = 2 and 4.5). These second-neighbor Cl atoms were also detected at low Au concentrations (10 -3 M) and are similar in number and arrangement to those observed in crystalline KAuCL 4·2H 2O (two Cl at a mean d[Au-Cl(2)] = 4.42 ± 0.03 Å). No evidence was found for second-neighbor Au atoms, which indicates little or no Au polymers or colloidal particles in any of the solutions studied. Our EXAFS results are in broad agreement with earlier predictions of Au speciation based on a variety of chemical measurements. Moreover, they directly confirm that mixed chloro-hydroxo Au (III) complexes are more stable than predicted on the basis of thermodynamically estimated stability constants.

(N-Benzyl-N-ethyl-dithio-carbamato)di-tert-butyl-chloridotin(IV).

PubMed

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R T

2011-02-26

The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)Cl(C(10)H(12)NS(2))], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C-H⋯π contacts link centrosymmetrically related mol-ecules into dimeric aggregates.

Synthesis, characterization and optical non-linearity of two heterobimetallic copper clusters containing tetraselenometalates

NASA Astrophysics Data System (ADS)

Zhang, Qian-Feng; Zhang, Chi; Song, Ying-Lin; Xin, Xin-Quan

2000-07-01

Cluster [{MoCu 3Se 3Br}(PPh 3) 3Se]·3THF·H 2O ( 1·3THF·H 2O) was prepared from reaction of [Et 4N] 2[MoSe] 4, Cu(PPh 3) 2NO 3 and Et 4N·Br in CH 2Cl 2 solution; also, 1 can be also obtained from the reaction of [MoSe 4Cu 4Py 6Br 2] and excess PPh 3 in a DMF-CH 2Cl 2 mixture solvent. The 95Mo NMR technique was used to monitor the above two reaction processes. X-ray crystallographic structure determination shows that it contains a strongly distorted cubane-like {MoCu 3Se 3Br} core. The coordination of the central Mo atom and each Cu atom are distorted from tetrahedral. Cluster [{WCu 3Se 3Cl}(PPh 3) 3Se] ( 2) was synthesized by the reaction of [Et 4N] 2[WSe] 4 and Cu(PPh 3) 2Cl in the solid state for nonlinear optical (NLO) studies. Its structure was reported by Ibers (Inorg. Chem. 31 (1992) 4365). The NLO properties of clusters 1 and 2 were studied. Both NLO absorption and refraction were obtained, and their effective third-order non-linearities were detected with α2=3.4×10 -10 and 5.9×10 -10 m/W and n2=-1.5×10 -17 and -1.3×10 -17 m 2/W , respectively, for the same concentration CH 2Cl 2 solution of 1 and 2. Influence of skeletal atoms to nonlinear absorption is also discussed in the paper.

Transition-Metal Derivatives of a Functionalized Cyclopentadienyl Ligand. 15. Synthesis and Structures of Amino Cyclopentadienyl Derivatives of Rhodium(I) and Rhodium(III) Including Water-Soluble Compounds.

PubMed

Philippopoulos, Athanassios I.; Hadjiliadis, Nick; Hart, Claire E.; Donnadieu, Bruno; Mc Gowan, Patrick C.; Poilblanc, René

1997-04-23

The synthesis of monometallic rhodium(III) and rhodium(I) derivatives of dialkylamino-functionalized cyclopentadienyl using the corresponding cyclopentadiene as starting material is facilitated by the presence of the basic amino group. This procedure affords the chloro salts of the substituted rhodicinium cation [(eta(5)-C(5)H(4)(CH(2))(2)NMe(2)H)(2)Rh(III)](3+) ([1][Cl](3)) from the reaction of the [2-(dimethylamino)ethyl]cyclopentadiene with Na(3)Rh(III)Cl(6). 12H(2)O. Similarly the cationic half-sandwich complexes [(eta(5)-C(5)H(4)(CH(2))(n)()NMe(2)H)Rh(I)(cod)](+) (n = 2, [2][Cl], n = 3, [5][Cl]) are obtained from the reaction of the corresponding dialkylamino cyclopentadiene with [RhCl(cod)](2). These types of cationic complexes, 1, 2, and 5, bear pendant ammonium groups. The most classical procedure, starting from the lithium or more efficiently from the sodium cyclopentadienide salt, was used to synthesize neutral complexes [(eta(5)-C(5)H(4)(CH(2))(n)()NMe(2))Rh(I)(cod)] (n = 2, 3; n = 3, 4). The structure of the chloride bis(hexafluorophosphate) salt, [(eta(5)-C(5)H(4)(CH(2))(2)NMe(2)H)(2)Rh(III)](3+)(Cl(-))(PF(6)(-))(2), ([1][Cl][PF(6)](2)) was solved in the triclinic space group P&onemacr; with one molecule in the unit cell, the dimensions of which are a = 6.617(2) Å, b= 7.436(2) Å, c = 13.965(3) Å, alpha = 76.39(2) degrees, beta = 82.31(3) degrees, gamma = 87.26(2) degrees, and V = 661.8(3) Å(3). The noncentrosymmetric character of this solid is attributed to the chloride ion. The tetrafluoroborate salt [(eta(5)-C(5)H(4)(CH(2))(2)NMe(2)H)Rh(I)(cod)](+)(BF(4)(-)) ([2][BF(4)]) crystallizes in the tetragonal space group P4(2)/n with eight molecules in the unit cell, the dimensions of which are a= 21.183(2) Å, b = 21.179(3) Å, c= 8.324(2) Å, and V = 3734(1) Å(3). Least squares refinement leads to values for the conventional R index of [1][Cl][PF(6)](2) (0.0484 for 2191 reflections used) and of [2][BF(4)] (0.0525 for 1083 reflections used); in both cases I > 3sigma(I). As expected, compounds like [2][Cl](3,) [1][Cl][PF(6)](2), [2][Cl], [2][BF(4)], [5][Cl], and [5][BF(4)] are soluble in water.

Synthesis and structures of new niobium cluster compounds with pyridinium cations: (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH (Pyr: pyridine, Et: ethyl) and the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flemming, Anke; Hoppe, Alessandra; Koeckerling, Martin

2008-10-15

Slow crystallization of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}] from hot ethanol solution affords triclinic (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH. Treatment of [Nb{sub 6}Cl{sub 14}(H{sub 2}O){sub 4}].4H{sub 2}O with pyridine in a methanol solution gives the second title compound, the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}]. Both structures were determined by single crystal X-ray diffraction, (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH: P1-bar , a=9.3475(3), b=9.3957(3), c=10.8600(3) A, {alpha}=82.582(1){sup o}, {beta}=78.608(1){sup o}, and {gamma}=78.085(1){sup o}, Z=1, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0254/0.0573, cub.-(PyrH){sub 2}[Nb{sub 6}Cl{sub 18}]: Fd3-bar m, a=19.935(2) A, Z=8, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0557/0.1796. The cluster compounds contain isolated, molecular [Nb{sub 6}Cl{sup i}{sub 12}Cl{sup a}{sub 6}]{supmore » 2-} cluster anions with an octahedron of metal atoms edge bridged by chlorido ligands with additional ones on all the six exo positions. These cluster anions are separated by the pyridinium cations and ethanol solvent molecules, respectively. For the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}], a structural comparison is given to the known rhombohedral modification using the group-subgroup relations as expressed by a Baernighausen tree. - Graphical abstract: The synthesis and structure of a second cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}] and of the new (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH are reported, both of which contain isolated niobium halide cluster anions with an octahedral core of metal atoms.« less

Heterometal cubane-type MFe(3)S(4) clusters (M = Mo, V) trigonally symmetrized with hydrotris(pyrazolyl)borate(1-) and tris(pyrazolyl)methanesulfonate(1-) capping ligands.

PubMed

Fomitchev, Dmitry V; McLauchlan, Craig C; Holm, R H

2002-02-25

A series of heterometal cubane-type clusters containing [VFe(3)S(4)](2+) and [MoFe(3)S(4)](3+,2+) cores has been prepared. Ligand substitution of [(DMF)(3)VFe(3)S(4)Cl(3)](-) affords [(Tpms)VFe(3)S(4)L(3)](2)(-) (L = Cl(-) (8), EtS(-) (9), p-MeC(6)H(4)S(-), p-MeC(6)H(4)O(-)). A new procedure for the preparation of molybdenum single cubanes is introduced by the reaction of recently reported [(Tp)MoS(S(4))](-) with FeCl(2)/NaSEt to afford [(Tp)MoFe(3)S(4)Cl(3)](-) (1, 75% yield). This procedure is more efficient that the existing multistep synthesis of single cubanes, which generally affords clusters of mirror symmetry. Also prepared were [(Tp)MoFe(3)S(4)L(3)](-) (L = EtS(-) (2), p-MeC(6)H(4)S(-)). Reduction of 1 with borohydride gives [(Tp)MoFe(3)S(4)Cl(3)](2-) (5, 67%). Owing to the nature of the heterometal ligand, all clusters have idealized trigonal symmetry, reflected in their (1)H NMR spectra. Trigonal structures are demonstrated by crystallography of (Bu(4)N)[1,2], (Bu(4)N)(2)[5] x MeCN, and (Me(4)N)(2)[8,9]. The availability of 1 and 5 allows the first comparison of structures and (57)Fe isomer shifts of [MoFe(3)S(4)](3+,2+) in a constant ligand environment. Small increases in most bond distances indicate that an antibonding electron is added in the reduction of 1. Collective synthetic and electrochemical results from this and other studies demonstrate the existence of the series of oxidation states [VFe(3)S(4)](3+,2+,1+) and [MoFe(3)S(4)](4+,3+,2+) whose relative stabilities within a given series are strongly ligand dependent. Isomer shifts indicate that the reduction of 1 largely affects the Fe(3) subcluster and are consistent with the formal descriptions [MoFe(3+)(2)Fe(2+)S(4)](3+) (1) and [MoFe(3+)Fe(2+)(2)S(4)](2+) (5). Reaction of 1 with excess Li(2)S in acetonitrile affords the double cubane [[(Tp)MoFe(3)S(4)Cl(2)](2)(mu(2)(-)S)](2)(-), whose sulfide-bridged structure is supported by two sequential reductions separated by 290 mV, in analogy with previously reported double cubanes of higher charge. Trigonally symmetric single cubanes eliminate isomers in the formation of double cubanes and other cluster structures, and may be of considerable value in the preparation of new types of M-Fe-S clusters. (Tpms = tris(pyrazolyl)methanesulfonate(1-); Tp = hydrotris(pyrazolyl)borate(1-).)

Crystal structures of bis-[(9S,13S,14S)-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate and tetra-chlorido-cuprate.

PubMed

Gauchat, Eric; Nazarenko, Alexander Y

2017-01-01

(9 S ,13 S ,14 S )-3-Meth-oxy-17-methyl-morphinan (dextromethorphan) forms two isostructural salts with ( a ) tetra-chlorido-cobaltate, namely bis-[(9 S ,13 S ,14 S )-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate, (C 18 H 26 NO) 2 [CoCl 4 ], and ( b ) tetra-chlorido-cuprate, namely bis-[(9 S ,13 S ,14 S )-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cuprate, (C 18 H 26 NO) 2 [CuCl 4 ]. The distorted tetra-hedral anions are located on twofold rotational axes. The dextromethorphan cation can be described as being composed of two ring systems, a tetra-hydro-naphthalene system A + B and a deca-hydro-isoquinolinium subunit C + D , that are nearly perpendicular to one another: the angle between mean planes of the A + B and C + D moieties is 78.8 (1)° for ( a ) and 79.0 (1)° for ( b ). Two symmetry-related cations of protonated dextromethorphan are connected to the tetra-chlorido-cobaltate (or tetra-chlorido-cuprate) anions via strong N-H⋯Cl hydrogen bonds, forming neutral ion associates. These associates are packed in the (001) plane with no strong attractive bonding between them. Both compounds are attractive crystalline forms for unambiguous identification of the dextromethorphan and, presumably, of its optical isomer, levomethorphan.

Synthesis of ruthenium(II) complexes containing hydroxymethylphosphines and their catalytic activities for hydrogenation of supercritical carbon dioxide.

PubMed

Kayaki, Yoshihito; Shimokawatoko, Yoshiki; Ikariya, Takao

2007-07-09

Ligand substitution of RuCl2[P(C6H5)3]3 and Cp*RuCl(isoprene) (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) complexes with hydroxymethylphosphines was investigated to develop new catalyst systems for CO2 hydrogenation. A reaction of P(C6H5)2CH2OH with RuCl2[P(C6H5)3]3 in CH2Cl2 gave Ru(H)Cl(CO)[P(C6H5)2CH2OH]3 (1), which was characterized by NMR spectroscopy and X-ray crystallographic analysis. An isotope labeling experiment using P(C6H5)213CH2OH indicated that the carbonyl moiety in complex 1 originated from formaldehyde formed by degradation of the hydroxymethylphosphine. Elimination of formaldehyde from PCy2CH2OH (Cy=cyclohexyl) was also promoted by treatment of RuCl2[P(C6H5)3]3 in ethanol to give RuCl2(PHCy2)4 under mild conditions. On the other hand, the substitution reaction using Cp*RuCl(isoprene) with the hydroxymethylphosphine ligands proceeded smoothly with formation of Cp*RuCl(L)2 [2a-2c; L=P(C6H5)2CH2OH, PCy(CH2OH)2, and P(CH2OH)3] in good yields. The isolable hydroxymethylphosphine complexes 1 and 2 efficiently catalyzed the hydrogenative amidation of supercritical carbon dioxide (scCO2) to N,N-dimethylformamide (DMF).

AtomicNuclearProperties

Science.gov Websites

) Polytrifluorochloroethylene [C2F3Cl]n Polyvinylacetate [CH2CHOCOCH3]n Polyvinyl alcohol (C2H3-O-H)n Polyvinyl butyral [C8H1302 other materal for properties of interest in high-energy physics: stopping power (<-dE/dx>) tables (C10H16O) Aniline (C6H5NH2) Anthracene (C14H10) Benzene C6H6 Butane (C4H10) n-Butyl alcohol (C4H9OH) Carbon

Fourier Transform Emission Spectroscopy of the [7.3] 2Δ- a2Φ and [9.4] 2Φ- a2Φ Systems of ZrCl

NASA Astrophysics Data System (ADS)

Ram, R. S.; Bernath, P. F.

1999-08-01

The emission spectrum of ZrCl has been observed in the 1800-12 000 cm-1 region using a Fourier transform spectrometer. The molecules were excited in a microwave discharge of a mixture of helium and a trace of ZrCl4 vapor. In addition to the C4Δ-X4Φ transition reported previously, numerous new bands observed in the near infrared have been classified into two electronic transitions, [7.3]2Δ-a2Φ and [9.4]2Φ-a2Φ. Five new bands observed in the 6700-7400 cm-1 region have been assigned as 2Δ3/2-2Φ5/2 and 2Δ5/2-2Φ7/2 subbands of a new electronic transition, [7.3]2Δ-a2Φ. The two subbands of the [9.4]2Φ-a2Φ transition were previously observed by G. Phillips, S. P. Davis, and D. C. Galehouse [Astrophys. J. Suppl. 43, 417-434 (1980)], who tentatively labeled them as 2Π1/2-2Π1/2 and 2Π3/2-2Π3/2 subbands. A number of new bands involving higher vibrational levels have been identified for these two subbands. A rotational analysis of a number of bands of both transitions has been obtained and spectroscopic constants have been determined. Global perturbations have been observed in both spin components of the a2Φ state. The assignment of the observed electronic states has been discussed in light of recent theoretical calculations.

Molybdenum complexes of 1,2-bis(diphenylphosphino)benzene. Mononuclear molybdenum(II) species formed by facile metal-metal bond cleavage of the (Mo-/sup 4/Mo)/sup 4+/ core

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bakir, M.; Cotton, F.A.; Cudahy, M.M.

1988-07-27

The quadruply bonded dimolybdenum(II) complexes K/sub 4/Mo/sub 2/Cl/sub 8/, (NH/sub 4/)/sub 5/MoCl/sub 9/ /times/ H/sub 2/O, and (NH/sub 4/)/sub 4/Mo/sub 2/Br/sub 8/ react with 1,2-C/sub 6/H/sub 4/(PPh/sub 2/)/sub 2/(dppbe) in methanol at room temperature to afford /alpha/-Mo/sub 2/X/sub 4/(dppbe)/sub 2/ complexes (X = Cl, Br), which do not isomerize to the /beta/ isomers. Under more forcing reactions conditions (refluxing 1-propanol), these same reactions give mononuclear trans-MoX/sub 2/(dppbe)/sub 2/ in good yield (ca. 50%) together with some (MoOX(dppbe)/sub 2/)X /times/ nH/sub 2/O. An alternative synthetic strategy for the preparation of /alpha/-Mo/sub 2/X/sub 4/(dppbe)/sub 2/ involves the reaction of Mo/sub 2/(O/sub 2/CCH/submore » 3/)/sub 4/ with dppbe and Me/sub 3/SiX in THF. The compound MoCl/sub 2/(dppbe)/sub 2/ forms crystals in space group P2/sub 1//n, with the following unit cell parameters: a = 10.884 (2) /angstrom/, b = 12.753 (2) /angstrom/, c = 18.141 (4) /angstrom/, /beta/ = 91.43 (2)/degree/, V = 2517 (2) /angstrom//sup 3/, and Z = 2. The centrosymmetric trans molecule has Mo-Cl = 2.410 (1) /angstrom/, Mo-P = 2.481 (1), 2.511 (1) /angstrom/, and P-Mo-P(intra-ring) = 78.68 (4)/degree/. 25 refs., 1 fig., 4 tabs.« less

Do group 1 metal salts form deep eutectic solvents?

PubMed

Abbott, A P; D'Agostino, C; Davis, S J; Gladden, L F; Mantle, M D

2016-09-14

Mixtures of metal salts such as ZnCl 2 , AlCl 3 and CrCl 3 ·6H 2 O form eutectic mixtures with complexing agents, such as urea. The aim of this research was to see if alkali metal salts also formed eutectics in the same way. It is shown that only a limited number of sodium salts form homogeneous liquids at ambient temperatures and then only with glycerol. None of these mixtures showed eutectic behaviour but the liquids showed the physical properties similar to the group of mixtures classified as deep eutectic solvents. This study focussed on four sodium salts: NaBr, NaOAc, NaOAc·3H 2 O and Na 2 B 4 O 7 ·10H 2 O. The ionic conductivity and viscosity of these salts with glycerol were studied, and it was found that unlike previous studies of quaternary ammonium salts with glycerol, where the salt decreased the viscosity, most of the sodium salts increased the viscosity. This suggests that sodium salts have a structure making effect on glycerol. This phenomenon is probably due to the high charge density of Na + , which coordinates to the glycerol. 1 H and 23 Na NMR diffusion and relaxation methods have been used to understand the molecular dynamics in the glycerol-salt mixtures, and probe the effect of water on some of these systems. The results reveal a complex dynamic behaviour of the different species within these liquids. Generally, the translational dynamics of the 1 H species, probed by means of PFG NMR diffusion coefficients, is in line with the viscosity of these liquids. However, 1 H and 23 Na T 1 relaxation measurements suggest that the Na-containing species also play a crucial role in the structure of the liquids.

Monohalogenated ferrocenes C5H5FeC5H4 X (X = Cl, Br and I) and a second polymorph of C5H5FeC5H4I

PubMed Central

Romanov, Alexander S.; Mulroy, Joseph M.; Khrustalev, Victor N.; Antipin, Mikhail Yu.; Timofeeva, Tatiana V.

2009-01-01

The structures of the three title monosubstituted ferrocenes, namely 1-chloro­ferrocene, [Fe(C5H5)(C5H4Cl)], (I), 1-bromo­ferrocene, [Fe(C5H5)(C5H4Br)], (II), and 1-iodo­ferrocene, [Fe(C5H5)(C5H4I)], (III), were determined at 100 K. The chloro- and bromo­ferrocenes are isomorphous crystals. The new triclinic polymorph [space group P , Z = 4, T = 100 K, V = 943.8 (4) Å3] of iodo­ferrocene, (III), and the previously reported monoclinic polymorph of (III) [Laus, Wurst & Schottenberger (2005 ▶). Z. Kristallogr. New Cryst. Struct. 220, 229–230; space group Pc, Z = 4, T = 100 K, V = 924.9 Å3] were obtained by crystallization from ethanolic solutions at 253 and 303 K, respectively. All four phases contain two independent mol­ecules in the unit cell. The relative orientations of the cyclo­penta­dienyl (Cp) rings are eclipsed and staggered in the independent mol­ecules of (I) and (II), while (III) demonstrates only an eclipsed conformation. The triclinic and monoclinic polymorphs of (III) contain nonbonded inter­molecular I⋯I contacts, causing different packing modes. In the triclinic form of (III), the mol­ecules are arranged in zigzag tetra­mers, while in the monoclinic form the mol­ecules are arranged in zigzag chains along the a axis. Crystallographic data for (III), along with the computed lattice energies of the two polymorphs, suggest that the monoclinic form is more stable. PMID:19893225

The Use of Cyclometalated NHCs and Pyrazoles for the Development of Fully Efficient Blue PtII Emitters and Pt/Ag Clusters.

PubMed

Arnal, Lorenzo; Fuertes, Sara; Martín, Antonio; Sicilia, Violeta

2018-05-15

New bis-pyrazole complexes [Pt(C^C*)(RpzH) 2 ]X, containing a cyclometalated N-heterocyclic carbene ligand (HC^C*=1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene) were prepared as chloride (X=Cl - , RpzH: 3,5-Me 2 pzH 1 a, 4-MepzH 2 a, pzH 3 a), perchlorate (X=ClO 4 - , 1 b-3 b), or hexafluorophosphate (X=PF 6 - , RpzH: 3,5-Me 2 pzH 1 c) salts. The X-ray structure of 1 a showed that the Cl - anion is trapped by the cation through two N-H⋅⋅⋅Cl bonds. In solution of methanol, acetone and THF at RT, 1 a-3 a coexist in equilibrium with the corresponding [PtCl(C^C*)(RpzH)] (B) and RpzH species. In CH 2 Cl 2 , this equilibrium takes place just for 2 a and 3 a, but it is completely shifted to the left at 243 and 223 K for 2 a and 3 a, respectively. The low-lying absorption and emission bands were assigned to intraligand (ILCT) charge transfer on the NHC group. Quantum yield measurements in PMMA films revealed that 1 b, 2 b and 1 c are amongst the most efficient blue-light emitters, with values up to 100 %. Proton abstraction from the coordinated 3,5-Me 2 pzH in 1 b by NEt 3 and replacement by Ag + afforded a neutral [Pt 2 Ag 2 ] cluster containing Pt→Ag dative bonds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Catalytic Silylation of N 2 and Synthesis of NH 3 and N 2H 4 by Net Hydrogen Atom Transfer Reactions Using a Chromium P 4 Macrocycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kendall, Alexander J.; Johnson, Samantha I.; Bullock, R. Morris

We report the first discrete molecular Cr-based catalysts for the reduction of N2. This study is focused on the reactivity of the Cr-N2 complex, trans-[Cr(N2)2(PPh4NBn4)] P4Cr(N2)2, bearing a 16-membered tetraphosphine macrocycle. The architecture of the [16]-PPh4NBn4 ligand is critical to preserve the structural integrity of the catalyst. P4Cr(N2)2 was found to mediate the reduction of N2 by three complementary reaction pathways: (1) Cr-catalyzed reduction of N2 to N(SiMe3)3 by Na and Me3SiCl affording up to 34 equiv N(SiMe3)3; (2) stoichiometric reduction of N2 by protons and electrons. For example, the reaction of cobaltocene (CoCp2) and collidinium triflate (ColH[OTf]) at roommore » temperature to afforded 1.9 equiv of NH3, or at -78 °C to afforded a mixture of NH3 and N2H4; (3) the first example of NH3 formation from the reaction of a terminally bound N2 ligand with a traditional H atom source, TEMPOH, (2,2,6,6-tetramethylpiperidine-1-ol). We found that trans-[Cr(15N2)2(PPh4NBn4)] reacts with excess TEMPOH to afford a 1.4 equiv of 15NH3.« less

Measurement of the absorption cross sections of SiCl4, SiCl3, SiCl2 and Cl at H Lyman-α wavelength

NASA Astrophysics Data System (ADS)

Mével, R.; Catoire, L.; Fikri, M.; Roth, P.

2013-03-01

Atomic resonance absorption spectroscopy coupled with a shock tube is a powerful technique for studying high temperature dynamics of reactive systems. Presently, high temperature pyrolysis of SiCl4-Ar mixtures has been studied behind reflected shock waves. Using time-resolved absorption profiles at 121.6 nm and a detailed reaction model, the absorption cross sections of SiCl, SiCl, SiCl and Cl have been measured. Results agree well with available data for SiCl and constitute, to our knowledge, the first measurements for SiCl, SiCl and Cl at the Lyman-α wavelength. These data are relevant to silica particle production from SiCl-oxidant mixtures combustion synthesis.

Thermal and optical properties of Tm3+ doped tellurite glasses.

PubMed

Ozen, G; Demirata, B; Oveçoğlu, M L; Genç, A

2001-02-01

Ultraviolet, visible (UV/VIS) and differential thermal analysis (DTA) measurements were carried out in order to investigate the optical and thermal properties of various 0.5 mol.% Tm2O3 containing (1 - x)TeO2 + xLiCl glasses in molar ratio. The samples were prepared by fusing the mixture of their respective reagent grade powders in a platinum cricuble at 750 degrees C for 30 min. DTA curves taken in the 23-600 degrees C temperature range with a heating rate of 10 degrees C/min reveal a change in the value of the glass transition temperature, Tg, while melting was not observed for the glasses containing LiCl content less than 50 mol.%. These glasses were found to be moisture-resistant. However, the glasses with LiCl content higher than 50 mol.%, in which a melting peak was observed at Tc = 401 degrees C, were moisture-sensitive. Absorption measurements in the UV/VIS region of the glasses without Tm2O3 content show that the Urbach cutoff occurs at about 320 nm and, is relatively independent of the LiCl content. Six absorption bands were observed in the Tm2O3 doped glasses corresponding to the absorption of the 1G4, 3F2, 3F3 and 3F4, 3H5 and 3H4 levels from the 3H6 ground level of Tm3+ ions. The spectra also show that the integrated absorption cross-section of each band depends on the glass composition. Judd-Ofelt theory was used to determine the Judd-Ofelt parameters as well as the radiative transition probabilities for the metastable levels of Tm3+ ions in (0.3)LiCl + (0.7) TeO2: 0.01 Tm2O3 glass which is moisture-resistant.

Asymmetrical A-Frame Triplatinum Clusters Bridged by Small Organic Molecules and Bis((diphenylphosphino)methyl)phenylphosphine.

PubMed

Tanase, Tomoaki; Ukaji, Hirokazu; Igoshi, Toshiaki; Yamamoto, Yasuhiro

1996-07-03

Reactions of the linear triplatinum complex [Pt(3)(&mgr;-dpmp)(2)(XylNC)(2)](2+) (3) with small organic molecules led to formation of asymmetrical A-frame triplatinum complexes with an additional bridge across one of the metal-metal bonds, where dpmp is bis((diphenylphosphino)methyl)phenylphosphine. Reaction of complex 3 with electron deficient alkynes (R(1)C&tbd1;CR(2): R(1) = R(2) = CO(2)Me; R(1) = H, R(2) = CO(2)Me; R(1) = R(2) = CO(2)Et) afforded a new series of triplatinum clusters formulated as [Pt(3)(&mgr;-dpmp)(2)(&mgr;-R(1)CCR(2))(XylNC)(2)](PF(6))(2) (5a, R(1) = R(2) = CO(2)Me; 5b, R(1) = H, R(2) = CO(2)Me; 5c, R(1) = R(2) = CO(2)Et) in good yields. The complex cation of 5b was characterized by X-ray crystallography to have an asymmetrical A-frame structure comprising three Pt atoms bridged by two dpmp ligands, in which an acetylene molecule was inserted into one of the Pt-Pt bonds (triclinic, P&onemacr;, a = 19.507(3) Å, b = 20.327(4) Å, c = 14.499(4) Å, alpha = 107.69(2) degrees, beta = 102.08(2) degrees, gamma = 71.30(1) degrees, V = 5148 Å(3), Z = 2, R = 0.070, and R(w) = 0.084). The Pt-Pt bond length is 2.718(1) Å and the Pt.Pt nonbonded distance is 3.582(1) Å. Treatment of 3 with an excess of HBF(4).Et(2)O gave the asymmetrical cluster [Pt(3)(&mgr;-dpmp)(2)(&mgr;-H)(XylNC)(2)](BF(4))(3).CH(2)Cl(2) (6.CH(2)Cl(2)), in 61% yield, and a similar reaction with p-NO(2)C(6)H(4)NC led to the formation of [Pt(3)(&mgr;-dpmp)(2)(&mgr;-R(3)NC)(XylNC)(2)](PF(6))(2).CH(2)Cl(2) (7.CH(2)Cl(2)) in 94% yield (R(3) = p-NO(2)C(6)H(4)). Complexes 6 and 7 are assumed to have a single atom-bridged, asymmetrical A-frame structures. Reaction of the complex syn-[Pt(2)(&mgr;-dpmp)(2)(XylNC)(2)](2+) (1) with [MCl(2)(cod)] (M = Pt, Pd) gave the dimer-monomer combined trinuclear cluster [Pt(2)MCl(2)(&mgr;-dpmp)(2)(XylNC)(2)](PF(6))(2) (8a, M = Pt, 89%; 8b, M = Pd, 55%). The structure of 8a was determined by X-ray crystallography to be comprised of a metal-metal-bonded diplatinum core and a monomeric platinum center bridged by two dpmp ligands with a face-to-face arrangement (triclinic, P&onemacr;, a = 18.082(7) Å, b = 19.765(6) Å, c = 15.662(4) Å, alpha = 98.51(2) degrees, beta = 94.24(3) degrees, gamma = 109.82(2) degrees, V = 5161 Å(3), Z = 2, R = 0.069, and R(w) = 0.080). The Pt-Pt bond length is 2.681(2) Å and the Pt.Pt nonbonded distance is 3.219(2) Å. The heteronuclear complex 8b was transformed to an A-frame trinuclear cluster, [Pt(2)PdCl(&mgr;-Cl)(&mgr;-dpmp)(2)(XylNC)](PF(6))(2) (9), which was characterized by X-ray crystallography (monoclinic, C2/c, a = 33.750(9) Å, b = 28.289(9) Å, c = 23.845(8) Å, beta = 118.19(4) degrees, V = 20066 Å(3), Z = 8, R = 0.082, and R(w) = 0.077). The diplatinum unit (Pt-Pt = 2.606(2) Å) is connected to the mononuclear Pd center by a chloride bridge (Pt.Pd = 3.103(3) Å, Pt-Cl-Pd = 79.6(3) degrees ).

Sol-gel analogous aminolysis-ammonolysis of chlorosilanes to chlorine-free Si/(C)/N-materials.

PubMed

Wiltzsch, Conny; Wagler, Jörg; Roewer, Gerhard; Kroke, Edwin

2009-07-28

Large amounts of chlorosilanes, especially SiCl4 and CH3SiCl3, are produced as side-products of the industrial fabrication of solar or electronic grade silicon and the Müller-Rochow process. It was a goal of the present study to transform these compounds into useful chlorine-free precursors for Si/(C)/N ceramics via a sol-gel analogous liquid processing route. Chlorine substitution of the chlorosilanes (mixtures) with diethylamine did not yield chlorine-free products, complete reactions are only possible with lithium diethylamide. However, aminolyses with n-propylamine were successful. Transamination with ammonia was not possible with diethylaminosilanes but was with n-propylaminosilanes in various solvents. This result was attributed to steric reasons and polar interactions of the N-H groups. Colourless solid or liquid polysilazanes were obtained, depending on the silane (mixture) and the solvent. Transamination reactions of CH3Si(NH-n-Pr)3 in chloroform reproducibly yielded a cage-like oligosilazane of the composition (CH3)9Si9(NH)12N. Single crystal X-ray structure analysis revealed a seven-cyclic cluster containing four six- and three ten-membered silazane rings. This unique silazane cage as well as the other aminosilanes and the silazanes were comprehensively characterised using multi-nuclear solid state and solution NMR, elemental analyses and thermal gravimetry (TGA).

Oxidation of a guanine derivative coordinated to a Pt(IV) complex initiated by intermolecular nucleophilic attacks.

PubMed

Choi, Sunhee; Personick, Michelle L; Bogart, Justin A; Ryu, DaWeon; Redman, Romany M; Laryea-Walker, Edith

2011-03-28

In this study we report that fac-[Pt(IV)(dach)(9-EtG)Cl(3)](+) (dach = d,l-1,2-diaminocyclohexane, 9-EtG = 9-ethylguanine) in high pH (pH 12) or phosphate solution (pH 7.4) produces 8-oxo-9-EtG and Pt(II) species. The reaction in H(2)(18)O revealed that the oxygen atom in hydroxide or phosphate ends up at the C8 position of 8-oxo-G. The kinetics of the redox reaction was first order with respect to both Pt(IV)-G and free nucleophiles (OH(-) and phosphate). The oxidation of G initiated by hydroxide was approximately 30∼50 times faster than by phosphate in 100 mM NaCl solutions. The large entropy of activation of OH(-1) (ΔS(‡) = 26.6 ± 4.3 J mol(-1) K(-1)) due to the smaller size of OH(-) is interpreted to be responsible for the faster kinetics compared to phosphate (ΔS(‡) = -195.5 ± 11.1 J mol(-1) K(-1)). The enthalpy of activation for phosphate reaction is more favorable relative to the OH(-) reaction (ΔH(‡) = 35.4 ± 3.5 kJ mol(-1) for phosphate vs. 96.6 ± 11.4 kJ mol(-1) for OH(-1)). The kinetic isotope effect of H8 was determined to be 7.2 ± 0.2. The rate law, kinetic isotope effect, and isotopic labeling are consistent with a mechanism involving proton ionization at the C8 position as the rate determining step followed by two-electron transfer from G to Pt(IV).

Gas sorption and transition-metal cation separation with a thienothiophene based zirconium metal-organic framework

NASA Astrophysics Data System (ADS)

SK, Mostakim; Grzywa, Maciej; Volkmer, Dirk; Biswas, Shyam

2015-12-01

The modulated synthesis of the thienothiophene based zirconium metal-organic framework (MOF) material having formula [Zr6O4(OH)4(DMTDC)6]·4.8DMF·10H2O (1) (H2DMTDC=3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid; DMF=N,N'-dimethylformamide) was carried out by heating a mixture of ZrCl4, H2DMTDC linker and benzoic acid (used as a modulator) with a molar ratio of 1:1:30 in DMF at 150 °C for 24 h. Systematic investigations have been performed in order to realize the effect of ZrCl4/benzoic acid molar ratio on the crystallinity of the material. The activation (i.e., the removal of the guest solvent molecules from the pores) of as-synthesized compound was achieved by stirring it with methanol and subsequently heating under vacuum. A combination of X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric (TG) and elemental analysis was used to examine the phase purity of the as-synthesized and thermally activated 1. The material displays high thermal stability up to 310 °C in an air atmosphere. As revealed from the XRD measurements, the compound retains its crystallinity when treated with water, acetic acid and 1 M HCl solutions. The N2 and CO2 sorption analyses suggest that the material possesses remarkably high microporosity (SBET=1236 m2 g-1; CO2 uptake=3.5 mmol g-1 at 1 bar and 0 °C). The compound also shows selective adsorption behavior for Cu2+ over Co2+ and Ni2+ ions.

Competitive reactions among glutathione, cisplatin and copper-phenanthroline complexes.

PubMed

Cadoni, Enzo; Valletta, Elisa; Caddeo, Graziano; Isaia, Francesco; Cabiddu, Maria Grazia; Vascellari, Sarah; Pivetta, Tiziana

2017-08-01

A large number of cancers are treated with cisplatin (CDDP). However, its use is limited by drug resistance, which is often related to intracellular levels of thiol-containing molecules such as glutathione (GSH). The role of GSH in cisplatin-resistant cancer cells is still unclear. GSH may form adducts with CDDP which results in the deactivation of the drug, and, actually, a high intracellular level of GSH was observed in some cisplatin-resistant cancers. To overcome drug resistance, CDDP is often administered in combination with one or more drugs to exploit a possible synergistic effect. In previous studies, we observed that the sensitivity to CDDP of leukemic and ovarian cisplatin-resistant cancer cells was restored in the presence of [Cu(phen) 2 (H 2 O)](ClO 4 ) 2 (C0) (phen is 1,10-phenathroline). In order to clarify the possible interactions between GSH and CDDP, the reactivity and competitive reactions among CDDP, C0 and GSH in binary and ternary mixtures were studied. The investigation was extended also to [Cu(phen)(H 2 O) 2 (ClO 4 ) 2 ] (C10) and GSSG, the oxidized form of GSH. It was observed that CDDP was able to react with the studied copper complexes and with GSH or GSSG. However, in mixtures containing CDDP, GSH or GSSG and C0 or C10, only copper-glutathione complexes were detected, while no platinum-glutathione adducts were found. Copyright © 2017 Elsevier Inc. All rights reserved.

Population pharmacokinetics of ticagrelor and AR-C124910XX in patients with prior myocardial infarction
.

PubMed

Röshammar, Daniel; Bergstrand, Martin; Andersson, Tomas; Storey, Robert F; Hamrén, Bengt

2017-05-01

The population pharmacokinetics of ticagrelor and its active metabolite AR-C124910XX were characterized following ticagrelor 60 mg or 90 mg twice daily oral long-term treatment in 4,426 patients with a history of myocardial infarction. The ticagrelor and AR-C124910XX plasma concentration-time data were described by one-compartment models with first-order absorption or metabolite formation and elimination. Systemic exposure to ticagrelor and AR-C124910XX were stable over time. Ticagrelor apparent clearance (CL/F) was 17 L/h for the 60-mg and 15.4 L/h for the 90-mg dose. The CL/F of AR-C124910XX was 11.1 L/h for the 60-mg and 9.95 L/h for the 90-mg dose. Both ticagrelor and AR-C124910XX CL/F were independently influenced by body weight, sex, age, smoking, and Japanese ethnicity. Female sex and age > 75 years were the only categorical covariates, having more than 20% effect on AR-C124910XX CL/F. Ticagrelor CL/F was 6% higher and 11% lower, whereas AR-C124910XX CL/F was 26% higher and 34% lower for patients weighing 110 and 50 kg, respectively, compared with an 83 kg patient. The small differences in exposure to both ticagrelor and AR-C124910XX between demographic subgroups were in accordance with the consistent efficacy and safety outcomes observed across the population. The results were similar to those observed previously in patients with acute coronary syndromes.
.

Candida antartica lipase B catalyzed polycaprolactone synthesis: effects of organic media and temperature.

PubMed

Kumar, A; Gross, R A

2000-01-01

Engineering of the reaction medium and study of an expanded range of reaction temperatures were carried out in an effort to positively influence the outcome of Novozyme-435 (immobilized Lipase B from Candida antarctica) catalyzed epsilon-CL polymerizations. A series of solvents including acetonitrile, dioxane, tetrahydrofuran, chloroform, butyl ether, isopropyl ether, isooctane, and toluene (log P from -1.1 to 4.5) were evaluated at 70 degrees C. Statistically (ANOVA), two significant regions were observed. Solvents having log P values from -1.1 to 0.49 showed low propagation rates (< or = 30% epsilon-CL conversion in 4 h) and gave products of short chain length (Mn < or = 5200 g/mol). In contrast, solvents with log P values from 1.9 to 4.5 showed enhanced propagation rates and afforded polymers of higher molecular weight (Mn = 11,500-17,000 g/mol). Toluene, a preferred solvent for this work, was studied at epsilon-CL to toluene (wt/vol) ratios from 1:1 to 10:1. The ratio 1:2 was selected since, for polymerizations at 70 degrees C, 0.3 mL of epsilon-CL and 4 h, gave high monomer conversions and Mn values (approximately 85% and approximately 17,000 g/mol, respectively). Increasing the scale of the reaction from 0.3 to 10 mL of CL resulted in a similar isolated product yield, but the Mn increased from 17,200 to 44,800 g/mol. Toluene appeared to help stabilize Novozyme-435 so that lipase-catalyzed polymerizations could be conducted effectively at 90 degrees C. For example, within only 2 h at 90 degrees C (toluene-d8 to epsilon-CL, 5:1, approximately 1% protein), the % monomer conversion reached approximately 90%. Also, the controlled character of these polymerizations as a function of reaction temperature was evaluated.

Spectral studies of SiCl4 + N2O + Ar and SiH4 + Ar mixtures in a shock tube in 160-550 nm range

NASA Technical Reports Server (NTRS)

Park, C.; Fujiwara, T.

1978-01-01

Gases containing SiO, SiO2, SiH, and Si2 were produced in the reflected-shock region of a shock tube by heating SiCl4 + N2O + Ar and SiH4 + Ar mixtures with shock waves. Spectral absorption characteristics were measured in the 160-550 nm wavelength range and in the 2800-3600 K temperature range and compared to calculated values. The sums of the squares of electronic transition moments at equilibrium separation were derived. It was found that absorption by SiO2 and other known bands of SiO, SiH, and Si2 were too weak to be measured. The cross section of absorption by a continuum, believed due to SiH, varied from 2.5 x 10 to the -17th sq cm at 280 nm to 1.6 x 10 to the -18th sq cm at 440 nm.

Arene-mercury complexes stabilized by gallium chloride: relative rates of H/D and arene exchange.

PubMed

Branch, Catherine S; Barron, Andrew R

2002-11-27

We have previously proposed that the Hg(arene)(2)(GaCl(4))(2) catalyzed H/D exchange reaction of C(6)D(6) with arenes occurs via an electrophilic aromatic substitution reaction in which the coordinated arene protonates the C(6)D(6). To investigate this mechanism, the kinetics of the Hg(C(6)H(5)Me)(2)(GaCl(4))(2) catalyzed H/D exchange reaction of C(6)D(6) with naphthalene has been studied. Separate second-order rate constants were determined for the 1- and 2-positions on naphthalene; that is, the initial rate of H/D exchange = k(1i)[Hg][C-H(1)] + k(2i)[Hg][C-H(2)]. The ratio of k(1i)/k(2i) ranges from 11 to 2.5 over the temperature range studied, commensurate with the proposed electrophilic aromatic substitution reaction. Observation of the reactions over an extended time period shows that the rates change with time, until they again reach a new and constant second-order kinetics regime. The overall form of the rate equation is unchanged: final rate = k(1f)[Hg][C-H(1)] + k(2f)[Hg][C-H(2)]. This change in the H/D exchange is accompanied by ligand exchange between Hg(C(6)D(6))(2)(GaCl(4))(2) and naphthalene to give Hg(C(10)H(8))(2)(GaCl(4))(2,) that has been characterized by (13)C CPMAS NMR and UV-visible spectroscopy. The activation parameters for the ligand exchange may be determined and are indicative of a dissociative reaction and are consistent with our previously calculated bond dissociation for Hg(C(6)H(6))(2)(AlCl(4))(2). The initial Hg(arene)(2)(GaCl(4))(2) catalyzed reaction of naphthalene with C(6)D(6) involves the deuteration of naphthalene by coordinated C(6)D(6); however, as ligand exchange progresses, the pathway for H/D exchange changes to where the protonation of C(6)D(6) by coordinated naphthalene dominates. The site selectivity for the H/D exchange is initially due to the electrophilic aromatic substitution of naphthalene. As ligand exchange occurs, this selectivity is controlled by the activation of the naphthalene C-H bonds by mercury.

Solvato-polymorph of [(η6-C6H6)RuCl (L)]PF6 (L = (2,6-dimethyl-phenyl-pyridin-2-yl methylene amine)

NASA Astrophysics Data System (ADS)

Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard

2016-06-01

A half-sandwich complex salt of ruthenium containing the Schiff base ligand, 2, 6-dimethyl-N-(pyridin-2-ylmethylene)aniline has been synthesized and structurally characterized. The complex salt 1, [(η6-C6H6)RuCl(C5H4NCHdbnd N(2,6-(CH3)2C6H3)]PF6 was obtained from the reaction of the ruthenium arene precursor, [(η6- C6H6)Ru(μ-Cl)Cl]2 with the Schiff base in a 1:2 ratio followed by treatment with NH4PF6. Its acetone solvate 2, [(η6-C6H6)RuCl(C5H4NCHdbnd N (2, 6- (CH3)2C6H3)]PF6. (CH3)2CO was obtained by recrystallization of 1 from a solution of hexane and acetone. 1 and 2 crystallize in the monoclinic P21/c and P21/n space groups as blocks and as prisms respectively. The ruthenium centers in 1 and 2 are coordinated to the bidentate Schiff base, to a chloride atom, and to the arene ring to give a pseudo-octahedral geometry around them. The whole arrangement is referred to as the familiar three-legged piano stool in which the Schiff base and the Cl atom serve as the base while the arene ring serve as the apex of the stool. Polymorph 2 has an acetone molecule in the asymmetric unit. Of interest is the similar behavior of the solvate on heating which shows the crystals shuttering at about 531.6 and 523.4 K for 1 and 2 respectively.

Nucleophilic ring opening of bridging thietanes in open triosmium cluster complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, R.D.; Belinski, J.A.

1992-07-01

The complexes Os{sub 3}(CO){sub 9}({mu}{sub 3}-S)[{mu}-SCH{sub 2}CMe{sub 2}CMe{sub 2}CH{sub 2}] (1) and Os{sub 3}(CO){sub 9}({mu}{sub 3}-S)[{mu}-SCH{sub 2}CH{sub 2}CH{sub 2}] (2) were obtained from the reactions of Os{sub 3}(CO){sub 10}({mu}{sub 3}-S) with 3,3-dimethylthietane (DMT) and thietane, respectively, at -42 {degree}C in the presence of Me{sub 3}NO. Compound 1 was characterized by a single-crystal X-ray diffraction analysis and was found to contain a DMT group bridging two of the nonbonded metal atoms in the open cluster of three metal atoms by using both lone pairs of electrons on the sulfur atom. Compound 1 reacted with bis(triphenylphosphine)nitrogen(1+) chloride ([PPN]Cl) at 25 {degrees}C tomore » yield the salt [PPN][Os{sub 3}-(CO){sub 9}({mu}-SCH{sub 2}CMe{sub 2}CH{sub 2}Cl)({mu}{sub 3}-S)] (3; 76%), in which the chloride ion was added to one of the methylene groups of the DMT ring in a process that caused the ring to open by cleavage of one of the carbon-sulfur bonds. A 4-chloro-3,3-dimethylpropanethiolate ligand bridges the open edge of the anionic triosmium cluster. Compound 3 was converted to the neutral complex Os{sub 3}(CO){sub 9}[{mu}-SCH{sub 2}CMe{sub 2}CMe{sub 2}CH{sub 2}Cl]({mu}{sub 3}-S)({mu}-H) (4) by reaction with HCl at 25 {degrees}C. Compound 4 is structurally similar to 3, except that is contains a hydride ligand bridging one of the two metal-metal bonds. Compounds 1 and 2 react with HCl in CH{sub 2}Cl{sub 2} solvent to yield the neutral compounds 4 and Os{sub 3}(CO){sub 9}[{mu}-SCH{sub 2}CH{sub 2}CH{sub 2}Cl]({mu}{sub 3}-S)({mu}-H) (5) in 89% and 90% yields, respectively, in one step. 11 refs., 3 figs., 10 tabs.« less

Deep extractive and oxidative desulfurization of dibenzothiophene with C5H9NO·SnCl2 coordinated ionic liquid.

PubMed

Li, Fa-tang; Kou, Cheng-guang; Sun, Zhi-min; Hao, Ying-juan; Liu, Rui-hong; Zhao, Di-shun

2012-02-29

A new C5H9NO·SnCl2 coordinated ionic liquid (IL) was prepared by reacting N-methyl-pyrrolidone with anhydrous SnCl2. Desulfurization of dibenzothiophene (DBT) via extraction and oxidation with C5H9NO·SnCl2 IL as extractant, H2O2 and equal mol of CH3COOH as oxidants was investigated. The Nernst partition coefficients k(N) of C5H9NO·SnCl2 IL for the DBT in n-octane was above 5.0, showing its excellent extraction ability. During the oxidative desulfurization process, the optimal molar ratio of H2O2/DBT was six. Sulfur removal of DBT in n-octane was 94.8% in 30 min at 30 °C under the conditions of H2O2/DBT molar ratio of six and V (IL):V (oil)=1:3. Moreover, the sulfur removal increased with increasing temperature because of the high reaction rate constant, low viscosity, and high solubility of dibenzothiophene-sulfone in the IL. The kinetics of oxidative desulfurization of DBT was also investigated, and the apparent activation energy was found to be 32.5 kJ/mol. The IL could be recycled six times without a significant decrease in activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)

NASA Astrophysics Data System (ADS)

Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)' providing data from direct measurement of pressure and mole fraction in vapor phase at variable mole fraction in liquid phase and constant temperature.

Mixture toxicity of water contaminants-effect analysis using the zebrafish embryo assay (Danio rerio).

PubMed

Schmidt, Susanne; Busch, Wibke; Altenburger, Rolf; Küster, Eberhard

2016-06-01

Three water contaminants were selected to be tested in the zebrafish embryo toxicity test (DarT) in order to investigate the sensitivity of the zebrafish embryo toxicity test with respect to mixture effect detection. The concentration-response curves for the observed effects lethality and hypo-pigmentation were calculated after an exposure of the embryos for 96 h with a fungicide (carbendazim), a plasticizer or propellent precursor (2,4-DNT: 2,4- dinitrotoluene) and an aromatic compound (AαC: 2-amino-9H-pyrido[2,3-b]indol), respectively. Follow-up mixture tests were based on the calculated LC50 or EC50 of the single compounds and combined effects were predicted according to the mixture concepts of concentration addition (CA) and independent action (IA). The order of toxicity for the single substances was carbendazim (LC50 = 1.25 μM) < AαC (LC50 = 8.16 μM) < 2,4-DNT (LC50 = 177.05 μM). For AαC and 2,4 DNT hypo-pigmentation was observed in addition (AαC EC50 = 1.81 μM; 2,4-DNT EC50 = 8.81 μM). Two binary and one ternary mixture were studied on lethality and one on hypo-pigmentation: 2,4-DNT/AαC (LC50 = 119.21 μM, EC50 = 5.37 μM), carbendazim/AαC (LC50 = 4.49 μM) and AαC/Carbendazim/2,4 DNT (LC50 = 108.62 μM). Results showed that the effects were in agreement with the CA model when substances were tested in mixtures. Therefore, in a reasonable worst case scenario substance combination effects in fish embryos were at maximum only prone to overestimation when using CA as the mixture concept. Copyright © 2016 Elsevier Ltd. All rights reserved.

Solubility relations in the ternary system NaCl-CsCl-H2O at 1 atm. 1. Solubilities of halite from 20 to 100 °C

USGS Publications Warehouse

Chou, I.-Ming; Lee, R.D.

1983-01-01

Solubilities of halite in the ternary system NaCl-CsCl-H2O have been determined by the visual polythermal method at 1 atm from 20 to 100??C along five constant CsCl/(CsCl + H2O) weight ratio lines. These five constant weight ratios are 0.1, 0.2, 0.3, 0.4, and 0.5. The maximum uncertainties in these measurements are ??0.02 wt % NaCl and ??0.15??C. The data along each constant CsCl/(CsCl + H2O) weight ratio line were regressed to a smooth curve. The maximum deviation of the measured solubilities from the smooth curves is 0.06 wt % NaCl. Isothermal solubilities of halite were calculated from smoothed curves at 25, 50, and 75??C.

Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157:H7 cells protected by a biofilm.

PubMed

Kim, Nam Hee; Rhee, Min Suk

2016-06-16

The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22°C for 6days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p<0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4%) (p<0.05); indeed, the combination of 0.4% PA plus 3-4% NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a>6.5logCFU/cm(2) reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7logCFU/cm(2) reduction; NaCl, <0.5logCFU/cm(2) reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Infrared Spectra of Protonated Quinoline (1-C_9H_7NH^{+}) in Solid Para-Hydrogen

NASA Astrophysics Data System (ADS)

Tseng, Chih-Yu; Lee, Yuan-Pern

2017-06-01

Large protonated polycyclic aromatic hydrocarbons (H^{+}PAH) and polycyclic aromatic nitrogen heterocycles (H^{+}PANH) have been proposed as possible carriers of unidentified infrared (UIR) emission bands from galactic objects. The nitrogen atom in H^{+}PANH is expected to induce a blue shift of the C=C stretching band near 6.2 μm so that their emission bands might agree with the UIR band better than those of H^{+}PAH. In this work, we report the IR spectrum of protonated quinoline and its neutral species measured upon electron bombardment during deposition of a mixture of quinoline and para-hydrogen at 3.2 K. New features were assigned to 1-C_9H_7NH^{+} and 1-C_9H_7NH, indicating that the protonation and hydrogenation occur at the N-atom site. The intensities of features of 1-C_9H_7NH^{+} diminished when the matrix was maintained in darkness for 10 h, whereas those of 1-C_9H_7NH increased. Spectral assignments were made according to comparison of experimental results with anharmonic vibrational wavenumbers and IR intensities calculated with the B3LYP/6-311++G(d,p) method. Although agreement between the observed spectrum of 1-C_9H_7NH^{+} and the UIR emission bands is unsatisfactory, presumably because of the small size of quinoline, we did observe C=C stretching bands at 1641.4, 1598.4, 1562.0 \\wn, blue-shifted from those at 1618.7, 1580.8, 1510.0 \\wn of the corresponding protonated PAH (C_{10}H_{9}^{+}), pointing to the direction of the UIR bands.

1-[1-(4-Chloro-phen-yl)ethyl-idene]carbono-hydrazide.

PubMed

Du, Lingyun; Du, Lei; Wang, Shuhao

2009-08-12

The mol-ecular skeleton of the title mol-ecule, C(9)H(11)ClN(4)O, is essentially planar, the dihedral angle between the ring and the and N/N/C plane being 6.7 (3)°. In the crystal, inter-molecular N-H⋯O and N-H⋯N hydrogen bonds link the mol-ecules into ribbons propagated along [010].

Progress Towards Intersubband Quantum-Box Lasers for Highly Efficient Continuous Wave Operation in the Mid-Infrared

DTIC Science & Technology

2009-01-30

Fig. 7. ECV data for CH4/H2/Ar/Cl2/BCl3 and Cl2/ SiCl4 /Ar plasma etching. Ni < 1010/cm2. Subsequently, it was exposed to RIE...etching in either a CH4/H2/Ar/Cl2/BCl3 or a Cl2/ SiCl4 /Ar gas mixture which have been used to fabricate nanoposts for the IQB structures (see next...Argon +BCl3 as well as Inductive Coupled Plasma (ICP) etching using SiCl4 . Using both methods we were able to obtain 30-40 nm-diameter nanopoles on

GeSn growth kinetics in reduced pressure chemical vapor deposition from Ge2H6 and SnCl4

NASA Astrophysics Data System (ADS)

Aubin, J.; Hartmann, J. M.

2018-01-01

We have investigated the low temperature epitaxy of high Sn content GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool from Applied Materials. Gaseous digermane (Ge2H6) and liquid tin tetrachloride (SnCl4) were used as the Ge and Sn precursors, respectively. The impact of temperature (in the 300-350 °C range), Ge2H6 and SnCl4 mass-flows on the GeSn growth kinetics at 100 Torr has been thoroughly explored. Be it at 300 °C or 325 °C, a linear GeSn growth rate increase together with a sub-linear Sn concentration increase occurred as the SnCl4 mass-flow increased, irrespective of the Ge2H6 mass flow (fixed or varying). The Sn atoms seemed to catalyze H desorption from the surface, resulting in higher GeSn growth rates for high SnCl4 mass-flows (in the 4-21 nm min-1 range). The evolution of the Sn content x with the F (SnCl4) 2 ·/F (Ge2H6) mass-flow ratio was fitted by x2/(1 - x) = n ·F (SnCl4) 2 ·/F (Ge2H6), with n = 0.25 (325 °C) and 0.60 (300 °C). We have otherwise studied the impact of temperature, in the 300-350 °C range, on the GeSn growth kinetics. The GeSn growth rate exponentially increased with the temperature, from 15 up to 32 nm min-1. The associated activation energy was low, i.e. Ea = 10 kcal mol-1. Meanwhile, the Sn content decreased linearly as the growth temperature increased, from 15% at 300 °C down to 6% at 350 °C.

Transition metal coordination polymers based on tetrabromoterephthalic and bis(imidazole) ligands: Syntheses, structures, topological analysis and photoluminescence properties

NASA Astrophysics Data System (ADS)

Zhang, Xiaowei; Xing, Peiqi; Geng, Xiujuan; Sun, Daofeng; Xiao, Zhenyu; Wang, Lei

2015-09-01

Eight new coordination polymers (CPs), namely, [Zn(1,2-mbix)(tbtpa)]n (1), [Co(1,2-mbix)(tbtpa)]n (2), [CdCl(1,2-mbix)(tbtpa)0.5]n (3), {[Cd(1,2-bix)(tbtpa)]·H2O}n (4), {[Cd0.5(1,2-bix)(tbtpa)0.5]·H2O}n (5), {[Co0.5(1,2-bix)(tbtpa)0.5]·2H2O}n (6), {[Co(1,2-bix)(tbtpa)]·H2O}n (7) and {[Co(1,2-bix)(tbtpa)]·Diox·2H2O}n (8), were synthesized under solvothermal conditions based on mix-ligand strategy (H2tbtpa=tetrabromoterephthalic acid and 1,2-mbix=1,2-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene, 1,2-bix=1,2-bis(imidazol-1-ylmethyl)benzene). All of the CPs have been structurally characterized by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). X-ray diffraction analyses show that 1 and 2 are isotypics which have 2D highly undulated networks with (4,4)-sql topology with the existence of C-H ⋯Br interactions; for 3, it has a 2D planar network with (4,4)-sql topology with the occurrence of C-H ⋯Cl interactions other than C-H ⋯Br interactions; 4 shows a 3D 2-fold interpenetrated nets with rare 65·8-mok topology which has a self-catention property. As the same case as 1 and 2, 5 and 6 are also isostructural with planar layers with 44-sql topology which further assembled into 3D supramolecular structure through the interdigitated stacking fashion and the C-Br ⋯Cph interactions. As for 7, it has a 2D slightly undulated networks with (4,4)-sql topology which has one dimension channel. While 8 has a 2-fold interpenetrated networks with (3,4)-connect jeb topology with point symbol {63}{65·8}. And their structures can be tuned by conformations of bis(imidazol) ligands and solvent mixture. Besides, the TGA properties for all compounds and the luminescent properties for 1, 3, 4, 5 are discussed in detail.

Synthesis, crystal structure and characterization of a new organic-inorganic hybrid material 4-(ammonium methyl) pipyridinium hexachloro stanate (II) trihydrate

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-03-01

The present paper undertakes the study of (C6H16N2) SnCl6·3H2O which is a new hybrid compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. The single crystal X-ray diffraction studies revealed that the compound crystallizes in monoclinic Cc space group with cell parameters a = 8.3309(9) Å, b = 22.956(2) Å, c = 9.8381(9) Å, β = 101.334(9) ° and Z = 4. The atomic arrangement shows an alternation of organic and inorganic entities. The cohesion between these entities is performed via Nsbnd H⋯Cl, Nsbnd H⋯O, Osbnd H⋯Cl and Osbnd H⋯O hydrogen bonding to form a three-dimensional network. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electron microscope (SEM) was carried out. Furthermore, the room temperature infrared (IR) spectrum of the title compound was recorded and analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows four signals, confirming the solid state structure determined by X-ray diffraction. Besides, the thermal analysis studies were performed, but no phase transition was found in the temperature range between 30 and 450 °C. The optical and PL properties of the compound were investigated in the solid state at room temperature and exhibited three bands at 348 and 401 cm-1 and a strong fluorescence at 480 nm.

Prime Contractors with Awards over $25,000 by Name, Location, and Contract Number. Part 1 (102 Construction Inc, Oklahoma City, Oklahoma -- Billfish Inc, Los Angeles, California), FY1991

DTIC Science & Technology

1991-01-01

Da 0 ax 0.4, 000 acca C.- C.)6 NC Lnd6 O6 N0600- c r L oC~ n 6 - - n l NY m4 0 -4C LO -6 C D 0 𔃺 o, Lc (n - - -06 o lu . CO 60 ~ 0H0,1 (v( C0C(Jm >C...L) L 0 0 -0 V 0) 4. u 040.M C> .-C -5 -5 to F6 0(2~f (k).- I C - N3 1 0 :3. 0fH- WEO .4 C.4 jL I m0 N.-. 00 ’-0 0 . CC VN L. (2 CaI 0 m c 0 LL z 9 L

Synthesis, characterization and cytotoxic activity of substituted benzyl iminoether Pt(II) complexes of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}2] (R=Me, OMe, F). X-ray structure of trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}2].

PubMed

Mazzega Sbovata, Silvia; Bettio, Frazia; Marzano, Christine; Tassan, Augusto; Mozzon, Mirto; Bertani, Roberta; Benetollo, Franco; Michelin, Rino A

2008-04-01

New substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-R}(2)] (R=Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the (1)H NMR data. Complex trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes 1a and 5a showed IC(50) values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug.

The Crystal Structure of Ba 17Sm 10Cl 64

NASA Astrophysics Data System (ADS)

Liu, Guo; Eick, Harry A.

1999-08-01

The structure of Ba17Sm10Cl64, prepared by solvolytic extraction of a program-cooled 1:1 BaCl2:SmCl3 molar mixture sealed in a quartz tube and heated to 750°C, was determined from single-crystal X-ray diffraction data. The compound exhibits cubic symmetry, space group Pa3 (No. 205) with a=21.366(2) Å and Z=4. Refinement effected with I>2σ(I) yielded R1= 0.0926 and wR2=0.216. One Ba atom is 12-coordinated by Cl atoms in a distorted icosahedral arrangement; the three other Ba atoms are 10-coordinated in a distorted bicapped cubic arrangement. There are two Sm atom sites. The coordination around one Sm atom is best described as square antiprismatic, but one Sm-Cl distance is too long for effective bonding. The other Sm atom site, occupied statistically by {1}/{3}Ba and {2}/{3}Sm atoms, is 9-coordinated by Cl atoms in a monocapped square antiprismatic arrangement. The two types of Sm sites combine to form an M6Cl37 cuboctahedral cluster of the composition BaSm5Cl37. It is shown that the cβ phase identified previously in the Yb-F and related fluoride systems is probably isostructural with Ba17Sm10Cl64.

Lanthanide contraction effect on crystal structures of lanthanide coordination polymers with cyclohexanocucurbit[6]uril ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Li-Mei; Liu, Jing-Xin, E-mail: jxliu411@ahut.edu.cn

A series of compounds based on the macrocyclic ligand cyclohexanocucurbit[6]uril (Cy6Q[6]) with formulas (Ln(H{sub 2}O){sub 6}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·xH{sub 2}O [isomorphous with Ln=La (1), Ce (2), Pr (3) and Nd (4), x=11 (1), 11 (2), 10 (3) and 11 (4)], (Sm(H{sub 2}O){sub 5}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·10H{sub 2}O (5) and (Ln(H{sub 2}O){sub 5}(NO{sub 3})@Cy6Q[6])·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with Ln=Gd (6), Tb (7) and Dy (8), x=8 (6), 6 (7) and 6 (8)], have been successfully synthesized by the self-assembly of Cy6Q[6] with the corresponding lanthanide nitrate under hydrochloric acid aqueous solution in the presence of CdCl{sub 2}. Single-crystal X-ray diffraction analyses revealedmore » that compounds 1–8 all crystallize in monoclinic space group P2{sub 1}/c, and display 1D coordination polymer structures. The lanthanide contraction effect on the structures of 1–8 has also been investigated and discussed in detail. In contrast, the reaction of Cy6Q[6] with the Ho(NO){sub 3}, Tm(NO){sub 3}, Yb(NO){sub 3} under the same conditions resulted in the compounds 9–11 with formulas Cy6Q[6]·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with x=10 (9), 10 (10), and 9 (11)], in which no lanthanide cations are observed. The structural difference of these compounds indicates that the Cy6Q[6] may be used in the separation of lanthanide cations. - Graphical abstract: The reaction of cyclohexanocucurbit[6]uril with lanthanide ions (La{sup 3+}, Ce{sup 3+}, Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Gd{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Ho{sup 3+}, Tm{sup 3+} and Yb{sup 3+}) under hydrochloric acid in the presence of CdCl{sub 2} resulted in eleven compounds, which demonstrate interesting lanthanide contraction effect and provide a means of separating lanthanide ions. - Highlights: • Eleven compounds of the Ln{sup 3+} with the Cy6Q[6] were synthesized and described. • Compounds 1-8 demonstrate interesting lanthanide contraction effect. • In solid-state structures of compounds 9-11, no lanthanide ions were observed. • This study provides a means of separating lanthanides cations.« less

The chemistry and preparation of tantalum complexes with 2,3-dihydroxy benzoic acid: Experimental and theoretical investigation

NASA Astrophysics Data System (ADS)

Hatzipanayioti, Despina; Kontotheodorou, Konstantinos

2011-03-01

The effect of 2,3-dihydroxybenzoic acid (2,3DHBA, pyrocatechuic acid) on the chloro-alkoxo-species [TaCl 5- x(OMe) x], formed by dissolving TaCl 5 in MeOH, has been studied. The coordination of 2,3DHBA-H 2- on Ta (V) replacing MeO-terminal groups was monitored via NMR spectroscopy. The yellow solid 1 was isolated from the mixture of TaCl 5, with neutral 2,3-DHBA, in MeOH. From this solid the elemental (C, H and Ta), the thermogravimetric analyses, the IR, NMR, ESR and electronic spectra support the formula Ta 2(2,3DHBA) 2(O) 2Cl 4(MeO) 4. The ESR spectrum of solid 1, at 4.2 K, shows a half-field signal apart from a multiline signal around g = 2, supporting evidence for semiquinone and Ta (IV) presence. The occurrence of superoxide radical, in the low temperature of ESR spectrum recording, cannot be ruled out. By heating the solid 1 at 500 °C, an oxide phase showing porous character (SEM) and retaining CO 2 (IR), is evident. Solid 1 heated at 900 °C, leads to the formation of β-Ta 2O 5 orthorhombic phase, as the XRD pattern indicates. The hydrolytic process of solid 1, in aqueous solutions, has been studied; the presence of paramagnetic species generated in situ upon addition of base and the consequent degradative process of 2,3-DHBA, under aerobic conditions is obvious. In order to gain information for the structure of solid 1, DFT calculations have been performed for some theoretical models, based on the empirical formula of solid 1. The calculated structural and spectroscopic parameters have been correlated to experimental results. The energy optimized structures may give an idea about the way of MeCl and MeOMe formation as well some possible intermediates of the hydrolytic mechanism.

Influence of ammonium sulphate feeding time on fed-batch Arthrospira (Spirulina) platensis cultivation and biomass composition with and without pH control.

PubMed

Rodrigues, Mayla Santos; Ferreira, Lívia Seno; Converti, Attilio; Sato, Sunao; de Carvalho, João Carlos Monteiro

2011-06-01

Previous work demonstrated that a mixture of NH(4)Cl and KNO(3) as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely (NH(4))(2)SO(4) plus NaNO(3), varying the ammonium feeding time (T=7-15 days), either controlling the pH by CO(2) addition or not. A. platensis was cultivated in mini-tanks at 30°C, 156 μmol photons m(-2) s(-1), and starting cell concentration of 400 mg L(-1), on a modified Schlösser medium. T=13 days under pH control were selected as optimum conditions, ensuring the best results in terms of biomass production (maximum cell concentration of 2911 mg L(-1), cell productivity of 179 mg L(-1)d(-1) and specific growth rate of 0.77 d(-1)) and satisfactory protein and lipid contents (around 30% each). Copyright © 2011 Elsevier Ltd. All rights reserved.

Magnetic properties of 1 : 4 complexes of CoCl2 and pyridines carrying carbenes (S(0) = 4/2, 6/2, and 8/2) in diluted frozen solution; influence of carbene multiplicity on heterospin single-molecule magnets.

PubMed

Karasawa, Satoru; Nakano, Kimihiro; Tanokashira, Jun-ichi; Yamamoto, Noriko; Yoshizaki, Takahito; Koga, Noboru

2012-11-28

The microcrystalline sample of a parent complex, [CoCl(2)(py)(4)], showed a single-molecule magnet (SMM) behavior with an effective activation barrier, U(eff)/k(B), of 16 K for reversal of the magnetism in the presence of a dc field of 3 kOe. Pyridine ligands having 2-4 diazo moieties, DYpy; Y = 2, 3l, 3b, and 4, were prepared and confirmed to be quintet, septet, septet, and nonet in the ground state, respectively, after irradiation. The 1 : 4 complexes, CoCl(2)(DYpy)(4); Y = 2, 3l, 3b, and 4 in frozen solutions after irradiation showed the magnetic behaviors of SMMs with total spin multiplicity, S(total) = 17/2, 25/2, 25/2, and 33/2, respectively. Hysteresis loops depending on the temperature were observed and the values of coercive force, H(c), at 1.9 K were 12, 8.4, 11, and 8.1 kOe for CoCl(2)(CYpy)(4); Y = 2, 3l, 3b, and 4, respectively. In dynamic magnetic susceptibility experiments, ac magnetic susceptibility data obeyed the Arrhenius law to give U(eff)/k(B) values of 94, 92, 93, and 87 K for CoCl(2)(CYpy)(4); Y = 2, 3l, 3b, and 4, respectively, while the relaxation times for CoCl(2)(CYpy)(4); Y = 2 and 3l, obtained by dc magnetization decay in the range of 3.5-1.9 K slightly deviated downward from Arrhenius plots on cooling. The dynamic magnetic behaviors for CoCl(2)(CYpy)(4) including [CoCl(2)(py)(4)] and CoCl(2)(C1py)(4) suggested that the generated carbenes interacted with the cobalt ion to increase the relaxation time, τ(q), due to the spin quantum tunneling magnetization, which became larger with increasing S(total) of the complex.

Investigation of the hydrochlorination of SiCl4

NASA Technical Reports Server (NTRS)

Mui, J. Y. P.

1982-01-01

A research and development program on the hydrochlorination of silicon tetrachloride and metallurgical grade (m.g.) silicon metal to trichlorosilane was carried out as scheduled. Effects of pressure and temperature on this reaction are reported. The presence of HCl in the reaction product mixture was successfully analyzed. Approximately 0.1% to 0.5% HCl based on total chlorosilanes were produced by the hydrochlorination reaction. Experiments on the corrosion study were carried out to evaluate a variety of metals and alloys as the material of construction for the hydrochlorination reactor. Material includes carbon steel, nickel, copper, Alloy 400 (Monel), stainless steel (Type 304), Incoloy 800H and Hastelloy B-2. The corrosion test was carried out at reaction temperature of 500 C, pressure of 300 psig and H2/SiCl4 feed ratio of 2.0 for a total of 87 hours. Results of the corrosion test show that all the test samples achieved a weigh gain.

Gold Nanocluster-DNase 1 Hybrid Materials for DNA Contamination Sensing

DTIC Science & Technology

2014-01-01

or 1 mM) was added to 2 mL of protein solution under vigorous stirring at 37 ̊ C. After 5 minutes 200 µL of NaOH (1 M) was added to raise the pH to...12 for the 1, 5, and 10 mM HAuCl4 samples whereas 400 µL of NaOH (1M) was required. The various protein/gold mixtures were then left to react for...1: AuNCs were carried out in a final volume of 20 µL buffer (100 mM sodium acetate, 6.25 mM magnesium sulfate pH 5.0), containing 2 µg of dsDNA

Limits on the Higgs boson lifetime and width from its decay to four charged leptons

NASA Astrophysics Data System (ADS)

Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; de Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; van de Klundert, M.; van Haevermaet, H.; van Mechelen, P.; van Remortel, N.; van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; de Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; van Doninck, W.; van Mulders, P.; van Onsem, G. P.; van Parijs, I.; Barria, P.; Caillol, C.; Clerbaux, B.; de Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Perniè, L.; Randle-Conde, A.; Reis, T.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Beernaert, K.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; McCartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Sigamani, M.; Strobbe, N.; Tytgat, M.; van Driessche, W.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; da Silveira, G. G.; Delaere, C.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Mertens, A.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Beliy, N.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hamer, M.; Hensel, C.; Mora Herrera, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; da Costa, E. M.; de Jesus Damiao, D.; de Oliveira Martins, C.; Fonseca de Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; de Souza Santos, A.; Dogra, S.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; El-Khateeb, E.; Elkafrawy, T.; Mohamed, A.; Salama, E.; Calpas, B.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Dahms, T.; Davignon, O.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Lisniak, S.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Merlin, J. A.; Skovpen, K.; van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Bouvier, E.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Toriashvili, T.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heister, A.; Kiesel, M. 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M.; Lanza, G.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Branca, A.; Carlin, R.; Carvalho Antunes de Oliveira, A.; Checchia, P.; Dall'Osso, M.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Kanishchev, K.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Zanetti, M.; Zotto, P.; Zucchetta, A.; Zumerle, G.; Braghieri, A.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Mantovani, G.; Menichelli, M.; Saha, A.; Santocchia, A.; Spiezia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Broccolo, G.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Foà, L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Serban, A. T.; Spagnolo, P.; Squillacioti, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; D'Imperio, G.; Del Re, D.; Diemoz, M.; Gelli, S.; Jorda, C.; Longo, E.; Margaroli, F.; Meridiani, P.; Micheli, F.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Traczyk, P.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bellan, R.; Biino, C.; Cartiglia, N.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Musich, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Tamponi, U.; Belforte, S.; Candelise, V.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; La Licata, C.; Marone, M.; Schizzi, A.; Umer, T.; Zanetti, A.; Chang, S.; Kropivnitskaya, A.; Nam, S. K.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Kong, D. J.; Lee, S.; Oh, Y. D.; Sakharov, A.; Son, D. C.; Brochero Cifuentes, J. A.; Kim, H.; Kim, T. J.; Ryu, M. S.; Song, S.; Choi, S.; Go, Y.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, Y.; Lee, B.; Lee, K.; Lee, K. S.; Lee, S.; Park, S. K.; Roh, Y.; Yoo, H. D.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Choi, Y.; Choi, Y. K.; Goh, J.; Kim, D.; Kwon, E.; Lee, J.; Yu, I.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Komaragiri, J. R.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Casimiro Linares, E.; Castilla-Valdez, H.; de La Cruz-Burelo, E.; Heredia-de La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Vazquez Valencia, F.; Carpinteyro, S.; Pedraza, I.; Salazar Ibarguen, H. A.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Reucroft, S.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Khurshid, T.; Shoaib, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Brona, G.; Bunkowski, K.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Walczak, M.; Bargassa, P.; Beirão da Cruz E Silva, C.; di Francesco, A.; Faccioli, P.; Ferreira Parracho, P. 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V.; Vinogradov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Bunichev, V.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Myagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Tourtchanovitch, L.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Ekmedzic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Calvo, E.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; de La Cruz, B.; Delgado Peris, A.; Domínguez Vázquez, D.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro de Martino, E.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Albajar, C.; de Trocóniz, J. 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M.; Bloch, P.; Bocci, A.; Bonato, A.; Botta, C.; Breuker, H.; Camporesi, T.; Cerminara, G.; Colafranceschi, S.; D'Alfonso, M.; D'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; de Gruttola, M.; de Guio, F.; de Roeck, A.; de Visscher, S.; di Marco, E.; Dobson, M.; Dordevic, M.; Dorney, B.; Du Pree, T.; Dupont, N.; Elliott-Peisert, A.; Franzoni, G.; Funk, W.; Gigi, D.; Gill, K.; Giordano, D.; Girone, M.; Glege, F.; Guida, R.; Gundacker, S.; Guthoff, M.; Hammer, J.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kirschenmann, H.; Kortelainen, M. J.; Kousouris, K.; Krajczar, K.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Magini, N.; Malgeri, L.; Mannelli, M.; Martelli, A.; Masetti, L.; Meijers, F.; Mersi, S.; Meschi, E.; Moortgat, F.; Morovic, S.; Mulders, M.; Nemallapudi, M. V.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Piparo, D.; Racz, A.; Rolandi, G.; Rovere, M.; Ruan, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Sharma, A.; Silva, P.; Simon, M.; Sphicas, P.; Spiga, D.; Steggemann, J.; Stieger, B.; Stoye, M.; Takahashi, Y.; Treille, D.; Triossi, A.; Tsirou, A.; Veres, G. I.; Wardle, N.; Wöhri, H. K.; Zagozdzinska, A.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Buchmann, M. A.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dünser, M.; Eller, P.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marini, A. C.; Marionneau, M.; Martinez Ruiz Del Arbol, P.; Masciovecchio, M.; Meister, D.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrozzi, L.; Peruzzi, M.; Quittnat, M.; Rossini, M.; Starodumov, A.; Takahashi, M.; Tavolaro, V. R.; Theofilatos, K.; Wallny, R.; Aarrestad, T. K.; Amsler, C.; Caminada, L.; Canelli, M. F.; Chiochia, V.; de Cosa, A.; Galloni, C.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Lange, C.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Ronga, F. J.; Salerno, D.; Yang, Y.; Cardaci, M.; Chen, K. H.; Doan, T. H.; Ferro, C.; Jain, Sh.; Khurana, R.; Konyushikhin, M.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. S.; Bartek, R.; Chang, P.; Chang, Y. H.; Chang, Y. W.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Fiori, F.; Grundler, U.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Miñano Moya, M.; Petrakou, E.; Tsai, J. F.; Tzeng, Y. M.; Asavapibhop, B.; Kovitanggoon, K.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Cerci, S.; Dozen, C.; Girgis, S.; Gokbulut, G.; Guler, Y.; Gurpinar, E.; Hos, I.; Kangal, E. E.; Kayis Topaksu, A.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Tali, B.; Topakli, H.; Vergili, M.; Zorbilmez, C.; Akin, I. V.; Bilin, B.; Bilmis, S.; Isildak, B.; Karapinar, G.; Surat, U. E.; Yalvac, M.; Zeyrek, M.; Albayrak, E. A.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, T.; Cankocak, K.; Sen, S.; Vardarlı, F. I.; Grynyov, B.; Levchuk, L.; Sorokin, P.; Aggleton, R.; Ball, F.; Beck, L.; Brooke, J. J.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Meng, Z.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-Storey, S.; Senkin, S.; Smith, D.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Thomas, L.; Tomalin, I. R.; Williams, T.; Womersley, W. J.; Worm, S. D.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Bundock, A.; Burton, D.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Cripps, N.; Dauncey, P.; Davies, G.; de Wit, A.; Della Negra, M.; Dunne, P.; Elwood, A.; Ferguson, W.; Fulcher, J.; Futyan, D.; Hall, G.; Iles, G.; Karapostoli, G.; Kenzie, M.; Lane, R.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Nash, J.; Nikitenko, A.; Pela, J.; Pesaresi, M.; Petridis, K.; Raymond, D. M.; Richards, A.; Rose, A.; Seez, C.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leggat, D.; Leslie, D.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Pastika, N.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Gastler, D.; Lawson, P.; Rankin, D.; Richardson, C.; Rohlf, J.; St. John, J.; Sulak, L.; Zou, D.; Alimena, J.; Berry, E.; Bhattacharya, S.; Cutts, D.; Dhingra, N.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Sagir, S.; Sinthuprasith, T.; Breedon, R.; Breto, G.; Calderon de La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Saltzberg, D.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Ivova Paneva, M.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Luthra, A.; Malberti, M.; Olmedo Negrete, M.; Shrinivas, A.; Wei, H.; Wimpenny, S.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; D'Agnolo, R. T.; Holzner, A.; Kelley, R.; Klein, D.; Letts, J.; MacNeill, I.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Welke, C.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Flowers, K.; Franco Sevilla, M.; Geffert, P.; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Incandela, J.; Justus, C.; McColl, N.; Mullin, S. D.; Richman, J.; Stuart, D.; Suarez, I.; To, W.; West, C.; Yoo, J.; Anderson, D.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Pierini, M.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhu, R. Y.; Azzolini, V.; Calamba, A.; Carlson, B.; Ferguson, T.; Iiyama, Y.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Ford, W. T.; Gaz, A.; Jensen, F.; Johnson, A.; Krohn, M.; Mulholland, T.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chatterjee, A.; Chaves, J.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Sun, W.; Tan, S. M.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Wittich, P.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Hu, Z.; Jindariani, S.; Johnson, M.; Joshi, U.; Jung, A. W.; Klima, B.; Kreis, B.; Kwan, S.; Lammel, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lopes de Sá, R.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Weber, H. A.; Whitbeck, A.; Yang, F.; Yin, H.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carnes, A.; Carver, M.; Curry, D.; Das, S.; di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Low, J. F.; Ma, P.; Matchev, K.; Mei, H.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rank, D.; Rossin, R.; Shchutska, L.; Snowball, M.; Sperka, D.; Wang, J.; Wang, S.; Yelton, J.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Ackert, A.; Adams, J. R.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Khatiwada, A.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Bhopatkar, V.; Hohlmann, M.; Kalakhety, H.; Mareskas-Palcek, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, I. D.; Silkworth, C.; Turner, P.; Varelas, N.; Wu, Z.; Zakaria, M.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tan, P.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Osherson, M.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; Xin, Y.; You, C.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P.; Majumder, D.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Svintradze, I.; Toda, S.; Lange, D.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Kunkle, J.; Lu, Y.; Mignerey, A. C.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Baty, A.; Bierwagen, K.; Brandt, S.; Busza, W.; Cali, I. A.; Demiragli, Z.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; McGinn, C.; Mironov, C.; Niu, X.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Sumorok, K.; Varma, M.; Velicanu, D.; Veverka, J.; Wang, J.; Wang, T. W.; Wyslouch, B.; Yang, M.; Zhukova, V.; Dahmes, B.; Finkel, A.; Gude, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Meier, F.; Monroy, J.; Ratnikov, F.; Siado, J. E.; Snow, G. R.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira de Lima, R.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Trovato, M.; Velasco, M.; Won, S.; Brinkerhoff, A.; Dev, N.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Pearson, T.; Planer, M.; Reinsvold, A.; Ruchti, R.; Smith, G.; Taroni, S.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Liu, B.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Palmer, C.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Malik, S.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Sun, J.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Redjimi, R.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Hindrichs, O.; Khukhunaishvili, A.; Petrillo, G.; Verzetti, M.; Demortier, L.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Lath, A.; Nash, K.; Panwalkar, S.; Park, M.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Foerster, M.; Riley, G.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Dalchenko, M.; de Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Krutelyov, V.; Montalvo, R.; Mueller, R.; Osipenkov, I.; Pakhotin, Y.; Patel, R.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Undleeb, S.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wolfe, E.; Wood, J.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Christian, A.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Gomber, B.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Ruggles, T.; Sarangi, T.; Savin, A.; Sharma, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; Cms Collaboration

2015-10-01

Constraints on the lifetime and width of the Higgs boson are obtained from H →Z Z →4 ℓ events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 fb-1 at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of τH<1.9 ×10-13 s at the 95% confidence level (C.L.), corresponding to a lower bound on the width of ΓH>3.5 ×10-9 MeV . The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter fΛ Q that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is ΓH<46 MeV with fΛ Q unconstrained and ΓH<26 MeV for fΛ Q=0 at the 95% C.L. The constraint fΛ Q<3.8 ×10-3 at the 95% C.L. is obtained for the expected standard model Higgs boson width.

Self-assembly of 2-aldehyde-8-hydroxyquinolinate-based lanthanide complexes and NIR luminescence

NASA Astrophysics Data System (ADS)

Zhang, Meiqi; Li, Hongfeng; Chen, Peng; Sun, Wenbin; Zhang, Lei; Yan, Pengfei

2015-02-01

Self-assembly reaction of 2-aldehyde-8-hydroxyquinoline, tris(hydroxymethyl)aminomethane and LnCl3ṡ6H2O affords a series of mononuclear lanthanide complexes Ce(baho)2·Et2O (1) (H2baho = 2,8-bis(2-(8-hydroxylquinolinyl))-1-aza-5-hydroxymethyl-3,7-dioxabicyclo[3.3.0]octane), Dy(nhm)2Cl·0.5H2O (2) and Ln(nhm)2Cl·0.5C6H14 (Ln = Ho (3), Er (4), Yb (5) and Hnhm = N-(2-(8-hydroxylquinolinyl)methylene)(trishydroxymethyl)methylamine. The crystal structures have been determined by X-ray crystallographic analysis, and the tetravalence of Ce in 1 has been proven by XPS. Interestingly, the positive charge of Ce4+ ion in 1 is neutralized by two deprotonated baho2- ligands, while two deprotonated nhm- ligands and one Cl- compensate the positive charge of Ln3+ ions in 2-5. Complex 5 exhibit essential NIR luminescence of Yb3+ ion with lifetime of 17.64 μs in solid and 9.96 μs in CH3OH solution.

THE INTERSECTION OF STABLE AND NON-EQUILIBRIUM TETRAHEDRA IN A MUTUAL 7- COMPONENT SYSTEM OF Li, Na, Rb, T1/Br, C1, NO$sub 3$, SO$sub 4$ (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dombrovskaya, N.S.; Khakhlova, N.V.; Alekseeva, E.A.

1961-04-21

The most stable configuration of the mixture of the 16 salts formed from Li, Na, Rb, Tl/Br, Cl, NO/sub 3/, and S0/sub 4/ con ture which however interact, resulting in a stable mixture. On the basis of exchange reactions the following equation has been derived: LiBr + NaNO/sub 3/ + RbCl + 1/2Tl/sub 2/SO/sub 4/ = 1/ 2LiSO/sub 4/ + NaCl + RbNO/sub 3/ + TlBr. In addition, several binary complexes are also formed, such as Li/sub 2/SO/sub 4/ - Rb/sub 2/SO/sub 4/, 4Li/sub 2/SO/ sub 4/ - RbSO /sub 4/, RbCl - 2Li/sub 2/SO/sub 4/ and possible others. Inmore » view of the great interest, the intersection of stable and non-equilibrium tetrahedra consisting of components of both, was experimentally studied by thermai analysis. On the basis of cooling curves the following deflection points have been observed: 453 deg C, precipitation of the first Li/sub 2/SO/sub 4/ crystals; 409 deg , coprecipitation of Li/sub 2/SO/sub 4/ and NaCl; 391 deg , coprecipitation of Li/sub 2/SO/sub 4/, NaCl snd TlBr; and finally at 107 deg , formation of the quaternary eutectic with the previously mentioned salts + RbNO/sub 3/. The microstructures of the stable and non-equilibrium phases are quite similar. (TTT)« less

PCM Thermal Control of Nickel-Hydrogen Batteries

DTIC Science & Technology

1993-06-01

Iridium , Global Star, etc - The new satellite mobile telephone systems under development call for constellations of LEO satellites. A thermal problem unique...C6H4CI2 -16.7 88 2 4,6-dimethylindan C11H14 -16.7 88 3 2,2-dimethylpropane C5H12 -16.6 45 4 arsenic trichloride AsCl3 -16 56 5 quinoline C9H7N -15.6 84 6...discharge are: 0 SPACE-BASED RADAR - SBR is expected to have a surge power lasting about 9 minutes. 0 IRIDIUM - The high traffic associated with

Rocky Mountain Arsenal Northwest Boundary Containment/Treatment System Construction Report. Text, Drawings, Photos

DTIC Science & Technology

1986-03-01

Cl- a + -V- A0I CA. Ph~otographi 15. Back~ilI material for slurry trenCn. Photograph 16. Mixing, backfill and slurry. -do C3 -I 4CD 𔃾r4 "tý, WT 0 TD ...P-4 15.725 so S t 570-4 1󈨌- 154 ?5 % a0 37. 0-. P-2 20+25 55 9 41.0-50.0 IhQ , -C’h 411..# 0- 1 pj~ 4- 20+75 5? 9 41.0-50.0 ,’,St..,P-IC 24-(0 40 5

2-(3-Chloro­phen­yl)-4,5-dihydro-1H-imidazole

PubMed Central

Kia, Reza; Fun, Hoong-Kun; Kargar, Hadi

2009-01-01

In the title compound, C9H9ClN2, a substituted imidazoline, the six- and five-membered rings are twisted from each other, making a dihedral angle of 17.07 (5)°. In the crystal structure, a short Cl⋯Cl [3.3540 (3) Å] inter­action is observed. Neighbouring mol­ecules are linked together by inter­molecular N—H⋯N hydrogen bonds into a one-dimensional infinite chain along the [101] direction and short Cl⋯Cl contacts link the chains into a three-dimensional network. There is also a significant π-stacking inter­action between the planar sections of the six- and five-membered rings. PMID:21581940

The Kinetic Nonequilibrium Processes in the Internal Flow and in the Plume of Subsonic and Supersonic Aircrafts

NASA Technical Reports Server (NTRS)

Starik, Alexander M.

1997-01-01

(1) Our results show that under combustion of thermal destruction products of n-C8H18, and other hydrocarbon fuels with air at the equivalent ratio -0.5 and less the chemical equilibrium is not realized at the exit plane of combustion chamber and in the gas turbine and nozzle for most of small components such as NO2, NO3, HNO, HNO2, HNO3, N(x)H(y), HO2, OH. The chemical equilibrium is not realized in the internal flow of ramjet hydrogen combustion engine too. So at the nozzle exit plane both of gas-turbine hydrocarbon combustion engine and of ramjet hydrogen combustion engine the relatively large values of concentration of such small components as NO3, HNO2, N2O, HNO3, HNO, NH, N2H, HO2, H2O2 may be realized. The exact definition of these component concentration as well as concentration of NO(x), OH, SO2, O, H, H2, H2O at the nozzle exit plane is very important for plume chemistry. (2) The results which were obtained for subsonic and hypersonic aircrafts indicate on the considerable change of the composition of the gas mixture along the plume. This change can be caused not only by the mixture of combustion products with the atmosphere air but by proceeding of whole complex of nonequilibrium photochemical reactions. The photodissociation processes begin to influence on the formation of the free atoms and radicals at flight altitude H greater than or equal to 18 km. Neglect of these processes can result in essential (up to 10(exp 4) times) mistakes of values gamma(sub OH), gamma(sub O), gamma(sub H), gamma(sub HSO3) and some products of CFC's disintegration. It was found that penetration of Cl-containing species from the atmosphere into the exhaust flow and its interaction with nitrogen oxides leads to essential increasing of the concentration of Cl, Cl2, ClO2, ClNO3, CH3Cl and sometimes HCl and the decreasing of ClO concentration by comparison with background values. The results of our analysis show that the plume aircraft with both hydrocarbon and hydrogen combustion engine may be source of various pollutant components such as HNO, HNO4,ClO2, CH3NO2, CH3NO3, CH2O, Cl, H2O2, but not only NO, NO2, HNO2, HNO3, N2O5, SO2, SO3, H2SO4 as it was supposed before.

Calculation of the vapor-saturated liquidus for the NaCl-CO2-H2O system

USGS Publications Warehouse

Barton, P.B.; I-Ming, C.

1993-01-01

The polybaric liquidus surface for the H2O-rich corner of the NaCl-CO2-H2O ternary is calculated, relying heavily on 1. (1) a Henry's law equation for CO2 in brines (modified from Drummond, 1981), 2. (2) the assumption that the contributions of dissolved NaCl and CO2 in lowering the activity of H2O are additive, and 3. (3) data on the CO2 clathrate solid solution (nominally CO2 ?? 7.3H2O, but ranging from 5.75 to 8 or 9 H2O) from Bozzo et al. (1975). The variation with composition of the activity of CO2??7.3H2O, or any other composition within the clathrate field, is small, thereby simplifying the calculations appreciably. Ternary invariant points are 1. (1) ternary eutectic at -21.5??C, with ice + clathrate + hydrohalite NaCl-??H2O + brine mNaCl = 5.15, mco2 = 0.22 + vapor Ptotal ??? Pco2 = 5.7 atm; 2. (2) peritectic at -9.6??C, with clathrate + hydrohalite + liquid CO2 + brine mNaCl = 5.18, mco2 = 0.55 + vapor (Ptotal ??? Pco2 = 26.47 atm); and 3. (3) peritectic slightly below +0.1 ??C, with halite + hydrohalite + liquid CO2 + brine (mNaCl ??? 5.5, mco2 ??? 0.64) + vapor (Ptotal ??? Pco2 ??? 34 atm). CO2 isobars have been contoured on the ternary liquidus and also on the 25??C isotherm. An important caveat regarding the application of this information to the interpretation of the freezing-thawing behavior of fluid inclusions is that metastable behavior is a common characteristic of the clathrate. ?? 1993.

Chlorine isotope fractionation between chloride (Cl-) and dichlorine (Cl2)

NASA Astrophysics Data System (ADS)

Giunta, Thomas; Labidi, Jabrane; Eggenkamp, Hans G. M.

2017-09-01

The use of chlorine stable isotopes (35Cl and 37Cl) can help to constrain natural processes that involve chlorine species with different oxidation states. Theoretical studies based on thermodynamic and quantum mechanical approaches predict large isotope fractionation during redox reactions but to date, these reactions have not been studied experimentally. Here, we explore the chlorine isotope fractionation during the oxidation of hydrated Cl- (redox state of -I) to Cl2 (redox state of 0) at 25 °C and at 0 °C. Our apparatus consists of a sealed glass reactor where liquid HCl is mixed with liquid H2O2, a strong oxidant. Following complex reaction pathways, this mixture ultimately leads to the oxidation of Cl- and to the formation of Cl2 gas. As long as it is degassing, the Cl2 gas is flushed out of solution using N2 as a vector-gas from the glass-reactor to a potassium hydroxide (KOH) solution (pH 14) where it disproportionates into soluble species: Cl- and ClO-. After each experiment, the chlorine isotopic composition was measured in the recovered KOH-trap solution, as well as in the residual HCl solution. Consistent with theoretical predictions, the produced Cl2 gas is always enriched in the heavier 37Cl as compared to the initial Cl-reservoir. The following isotope fractionation factors are obtained: At 0 °C the isotopic fractionation 1000ln α(Cl2-Cl-) is 4.51 (+1.65/-0.49)‰ At 25 °C the isotopic fractionation 1000ln α(Cl2-Cl-) is 3.94 (+0.69/-0.18)‰. From the obtained data it is suggested that the production of Cl2 gas in our experiments is best described by a closed-system distillation. Our results are in agreement with published theoretical ab-initio calculations.

Structural characterization of selenium and selenium-diiodine analogues of the antithyroid drug 6-n-propyl-2-thiouracil and its alkyl derivatives.

PubMed

Antoniadis, Constantinos D; Blake, Alexander J; Hadjikakou, Sotiris K; Hadjiliadis, Nick; Hubberstey, Peter; Schröder, Martin; Wilson, Claire

2006-08-01

The structures of four selenium analogues of the antithyroid drug 6-n-propyl-2-thiouracil [systematic name: 2,3-dihydro-6-n-propyl-2-thioxopyrimidin-4(1H)-one], namely 6-methyl-2-selenouracil, C(5)H(6)N(2)OSe (1), 6-ethyl-2-selenouracil, C(6)H(8)N(2)OSe (2), 6-n-propyl-2-selenouracil, C(7)H(10)N(2)OSe (3), and 6-isopropyl-2-selenouracil, C(7)H(10)N(2)OSe (4), are described, along with that of the dichloromethane monosolvate of 6-isopropyl-2-selenouracil, C(7)H(10)N(2)OSe.CH(2)Cl(2) (4.CH(2)Cl(2)). The extended structure of (1) is a two-dimensional sheet of topology 6(3) with a brick-wall architecture. The extended structures of (2) and (4) are analogous, being based on a chain of eight-membered R(8)(6)(32) hydrogen-bonded rings. In (3) and (4.CH(2)Cl(2)), R(2)(2)(8) hydrogen bonding links molecules into chains. 6-n-Propyl-2-selenouracil.I(2), C(7)H(10)N(2)OSe.I(2) (7), is a charge-transfer complex with a ;spoke' structure, the extended structure of which is based on a linear chain formed principally by intermolecular N-H...O hydrogen bonds. Re-crystallization of 6-ethyl-2-selenouracil or (7) from acetone gave crystals of the diselenides [N-(6'-ethyl-4'-pyrimidone)(6-ethyl-2-selenouracil)(2)(Se-Se)].2H(2)O (9.2H(2)O) or [N-(6'-n-propyl-4'-pyrimidone)(6-n-propyl-2-selenouracil)(2)(Se-Se)] (10), respectively: these have similar extended chain structures formed via N-H...O and C-H...O hydrogen bonds, stacked to give two-dimensional sheets. Re-crystallization of (7) from methanol/acetonitrile led via deselenation to the formation of crystals of 6-n-propyl-2-uracil (11), in which six symmetry-related molecules combine to form a six-membered R(6)(6)(24) hydrogen-bonded ring, with each pair of molecules linked by an R(2)(2)(8) motif.

Method for enriching a gaseous isotopic mixture with at least one isotope

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Mevergnies, M.N.; Fettweis, P.

1982-02-02

There is described a method for enriching a gas-like isotopic mixture with at least one isotope, in which a mixture of Cf2Cl2 and O2 is irradiated by means of a pulsed and focalized laser beam having an optical frequency corresponding to a wave number lying in the band from 920 to 945 cm-1 to enrich the residual Cf2Cl2 with 37Cl, in the band from 1050 to 1075 cm-1 to produce CoF2 enriched with 13C and/or in the band from 1080 to 1095 cm-1 to enrich the residual Cf2Cl2 with 35Cl and 13C.

Fluid inclusion, rare earth element geochemistry, and isotopic characteristics of the eastern ore zone of the Baiyangping polymetallic Ore district, northwestern Yunnan Province, China

NASA Astrophysics Data System (ADS)

Feng, Caixia; Bi, Xianwu; Liu, Shen; Hu, Ruizhong

2014-05-01

The Baiyangping Cu-Ag polymetallic ore district is located in the northern part of the Lanping-Simao foreland fold belt, which lies between the Jinshajiang-Ailaoshan and Lancangjiang faults in western Yunnan Province, China. The source of ore-forming fluids and materials within the eastern ore zone were investigated using fluid inclusion, rare earth element (REE), and isotopic (C, O, and S) analyses undertaken on sulfides, gangue minerals, wall rocks, and ores formed during the hydrothermal stage of mineralization. These analyses indicate: (1) The presence of five types of fluid inclusion, which contain various combinations of liquid (l) and vapor (v) phases at room temperature: (a) H2O (l), (b) H2O (l) + H2O (v), (c) H2O (v), (d) CmHn (v), and (e) H2O (l) + CO2 (l), sometimes with CO2 (v). These inclusions have salinities of 1.4-19.9 wt.% NaCl equivalents, with two modes at approximately 5-10 and 16-21 wt.% NaCl equivalent, and homogenization temperatures between 101 °C and 295 °C. Five components were identified in fluid inclusions using Raman microspectrometry: H2O, dolomite, calcite, CH4, and N2. (2) Calcite, dolomitized limestone, and dolomite contain total REE concentrations of 3.10-38.93 ppm, whereas wall rocks and ores contain REE concentrations of 1.21-196 ppm. Dolomitized limestone, dolomite, wall rock, and ore samples have similar chondrite-normalized REE patterns, with ores in the Huachangshan, Xiaquwu, and Dongzhiyan ore blocks having large negative δCe and δEu anomalies, which may be indicative of a change in redox conditions during fluid ascent, migration, and/or cooling. (3) δ34S values for sphalerite, galena, pyrite, and tetrahedrite sulfide samples range from -7.3‰ to 2.1‰, a wide range that indicates multiple sulfur sources. The basin contains numerous sources of S, and deriving S from a mixture of these sources could have yielded these near-zero values, either by mixing of S from different sources, or by changes in the geological conditions of seawater sulfate reduction to sulfur. (4) The C-O isotopic analyses yield δ13C values from ca. zero to -10‰, and a wider range of δ18O values from ca. +6 to +24‰, suggestive of mixing between mantle-derived magma and marine carbonate sources during the evolution of ore-forming fluids, although potential contributions from organic carbon and basinal brine sources should also be considered. These data indicate that ore-forming fluids were derived from a mixture of organism, basinal brine, and mantle-derived magma sources, and as such, the eastern ore zone of the Baiyangping polymetallic ore deposit should be classified as a “Lanping-type” ore deposit.

Synthesis, spectroscopic studies and electrochemistry of palladium (II) macrocyclic complexes derived from a new tetraazahalogen substituted ligands by template method and their antimicrobial and pesticidal activities

NASA Astrophysics Data System (ADS)

Masih, Iffat; Fahmi, Nighat

2011-09-01

A new series of Pd(II) macrocyclic complexes have been synthesized by template condensation of bis(benzil)4-chloro 1,2-phenylenediamine (ML 1) and bis(benzil)4-fluro 1,2-phenylenediamine (ML 2) respectively, with appropriate diamine i.e. 1,2-phenylenediamine, 4-chloro 1,2-phenylenediamine and 4-fluro 1,2-phenylenediamine in the presence of PdCl 2 to form complexes of the type [Pd(C 40H 26N 4ClF)]Cl 2, [Pd(C 40H 27N 4X)]Cl 2 and [Pd(C 40H 26N 4X 2)]Cl 2, where X = Cl, F. The complexes have been characterized with the help of elemental analysis, IR, 1H NMR, electronic spectra, conductance measurement, magnetic susceptibility, cyclic voltammetry and X-ray powder diffraction studies. On the basis of these studies a square planar geometry has been proposed around the metal ion. The newly synthesized ligands and their complexes have been screened for antimicrobial and pesticidal activities. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substance with pesticidal activity and promising antimicrobial activity.

Satellite Boreal Measurements over Alaska and Canada During June-July 2004: Simultaneous Measurements of Upper Tropospheric CO, C2H6, HCN, CH3Cl, CH4, C2H2, CH2OH, HCOOH, OCS, and SF6 Mixing Ratios

NASA Technical Reports Server (NTRS)

Rinsland, Curtis P.; Dufour, Gaelle; Boone, Chris D.; Bernath, Peter F.; Chiou, Linda; Coheur, Pierre-Francois; Turquety, Solene; Clerbaux, Cathy

2007-01-01

Simultaneous ACE (Atmospheric Chemistry Experiment) upper tropospheric CO, C2H6, HCN, CH3Cl, CH4 , C2H2 , CH30H, HCOOH, and OCS measurements show plumes up to 185 ppbv (10 (exp -9) per unit volume) for CO, 1.36 ppbv for C2H6, 755 pptv (10(exp -12) per unit volume) for HCN, 1.12 ppbv for CH3C1, 1.82 ppmv, (10(exp -6) per unit volume) for CH4, 0.178 ppbv for C2H2, 3.89 ppbv for CH30H, 0.843 ppbv for HCOOH, and 0.48 ppbv for OCS in western Canada and Alaska at 50 deg N-68 deg N latitude between 29 June and 23 July 2004. Enhancement ratios and emission factors for HCOOH, CH30H, HCN, C2H6, and OCS relative to CO at 250-350 hPa are inferred from measurements of young plumes compared with lower mixing ratios assumed to represent background conditions based on a CO emission factor derived from boreal measurements. Results are generally consistent with the limited data reported for various vegetative types and emission phases measured in extratropical forests including boreal forests. The low correlation between fire product emission mixing ratios and the S176 mixing ratio is consistent with no significant SF6 emissions from the biomass fires.

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place. Part 15 (Mountain States Caulking Inc-Pangborn Corp)

DTIC Science & Technology

1990-01-01

I 4 i (0> 0) (0 ?-- CoN 4C.A<>(0 0 9 3 020 i3f 04--4---0 -4 aNN C 0 VO N4 04000C0 33 3020 goN)L0(?-C 0 Of Co 0 ~ )0) 0)0) --- 03(3 C7(0 0)4 I3 3 02...M I -IO1 1 4NnInC0a laII0.I :Tl otIc 00o4-4 LIOr CO > -- 4-4 0-0-4 N m1 it-11m il C)I- o 00) 111 t 11 L- -4 0004 f Oi0 C ~ I -444- CON I NT N CL L...7) 0) I () 00 J! 0) 0)J 0. ) 0) 0) 0) .1  402 C 40 0 H 0 F- 0 0 H 344 if 2 I11-4" -I 0 a- 1- 1 0 0 444I CON 11I <- H < 044 : n 44 41 4cc 04E𔃺in

Solubility relations in the system sodium chloride-ferrous chloride-water between 25 and 70.degree.C at 1 atm

USGS Publications Warehouse

Chou, I.-Ming; Phan, L.D.

1985-01-01

Solubility relations in the ternary system NaCl-FeCl2-H2O have been determined by the visual polythermal method at 1 atm from 20 to 85??C along six composition lines. These she composition lines are defined by mixing FeCl2??4H2O with six aqueous NaCl solutions containing 5, 10, 11, 15, 20, and 25 wt % of NaCl, respectively. The solid phases encountered in these experiments were NaCl and FeCl2??4H2O. The maximum uncertainties in these measurements are ??0.02 wt % NaCl and ??0.15??C. The data along each composition line were regressed to a smooth curve when only one solid phase was stable. When two solids were stable along a composition line, the data were regressed to two smooth curves, the intersection of which indicated the point where the two solids coexisted. The maximum deviation of the measured solubilities from the smoothed curves is 0.14 wt % FeCl2. Isothermal solubilities of halite and FeCl2??4H2O were calculated from these smoothed curves at 25, 50, and 70 ??C.

Infrared Spectroscopy of 1-CHOLOROMETHYLALLYL and 1-METHYLALLYL Radicals Produced in a Solid Para-Hydrogen Matrix.

NASA Astrophysics Data System (ADS)

Bahou, Mohammed; Wu, Jen-Yu; Tanaka, Keiichi; Lee, Yuan-Pern

2012-06-01

The reaction of chlorine atoms with trans-1,3-butadiene in solid para-hydrogen (p-H_2) matrix has been studied using Fourier transform infrared spectroscopy. When a mixture of Cl_2, trans-1,3-butadiene and p-H_2 was deposited onto a cold target at 3 K and irradiated by UV light at 365 nm, new intense lines at 809.0, 962.1, 1240.6 cm-1 and several weaker ones appeared. The carrier of this spectrum was assigned to the 1-chloromethylallyl radical, - (CH_2CHCH)CH_2Cl, based on the anharmonic vibrational frequencies calculated with the DFT method, indicating that the addition of the Cl atom to trans-1,3-butadiene occurs primarily at the terminal carbon atom. This is in sharp contrast to the reaction of chlorine atoms with propene in a solid p-H_2 matrix in which the addition of Cl to the central carbon atom to produce selectively the 2-chloropropyl is favored due to the steric effects. The energy diagram calculated with B3PW91 method supports this selective reaction process because 1) the channel from trans-1,3-butadiene to 1-chloro-methylallyl is almost barrierless (0.4 kcal/mol), and 2) isomereization from 1-chloromethylally to the 2-chloro-3-buten-1-yl radical, CH_2CHCHClCH_2 - by migration of Cl atom from the terminal to the central C atom, hardly occur in the p-H_2 matrix because of the isomerization barrier height (18.8 kcal/mol). We also observed a second set of lines with intense ones at 781.6, 957.93, 1433.6 cm-1 and several weaker ones when the UV-irradiated Cl_2/trans-1,3-butadiene/p-H_2 matrix was further irradiated with infrared light from a globar source. These lines are assigned to the 1-methylallyl radical, - (CH_2CHCH)CH_3, produced from reaction of 1,3-butadiene with an H atom that was produced from the reaction of Cl atoms with IR-irradiated p-H_2, Cl + H_2^* → H + HCl. The energy diagram calculated at the G3//B3LYP level similarly supports the reaction process to form selectively 1-methylallyl in the p-H_2 matrix. J. C. Amicangelo and Y. P. Lee, J. Phys. Chem. Lett. 1, 1956 (2010). J. L. Millerngelo, J. Phys. Chem. A 108, 2268 (2004).

Design and syntheses of hybrid metal–organic materials based on K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] metallotectons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yayong; Zong, Yingxia; Ma, Haoran

2016-05-15

By using K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] (C{sub 2}O{sub 4}{sup 2−}=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C_2O_4)_2(H_2O)_2}{sub 2}]·(H–L{sub 1}){sub 2}·H{sub 2}O 1, [Fe(C{sub 2}O{sub 4})Cl{sub 2}]·(H{sub 2}–L{sub 2}){sub 0.5}·(L{sub 2}){sub 0.5}·H{sub 2}O 2, [{Fe(C_2O_4)_1_._5Cl_2}{sub 2}]·(H–L{sub 3}){sub 4}3, [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]·(H{sub 2}–L{sub 4}){sub 2}·2H{sub 2}O 4, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H{sub 2}–L{sub 5})·2H{sub 2}O 5, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 6, K[Cr(C{sub 2}O{sub 4}){sub 3}]·2H{sub 2}O 7, Na[Fe(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 8 (with L{sub 1}=4-dimethylaminopyridine, L{sub 2}=2,3,5,6-tetramethylpyrazine, L{sub 3}=2-aminobenzimidazole, L{sub 4}=1,4-bis-(1H-imidazol-1-yl)benzene, L{sub 5}=1,4-bis((2-methylimidazol-1-yl)methyl)benzene,more » L{sub 6}=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2}]{sup −} unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C{sub 2}O{sub 4})Cl{sub 2}]{sup -} anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe{sub 2}(C{sub 2}O{sub 4}){sub 3}Cl{sub 4}]{sup 4−} unit. Compound 4 features distinct [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]{sup 4−} units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C{sub 2}O{sub 4}){sub 3}]{sup 3−} units and K{sup +} cations. The 1D chains are further extended into 3D antionic H-bonded framework through O–H···O H-bonds. Compounds 6–8 show 2D [KAl(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer, [KCr(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer and [NaFe(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer, respectively. - Graphical abstract: We report here eight novel complexes by using [M(C{sub 2}O{sub 4}){sub 3}]{sup 3−} [M(III)=Fe, Al, Cr] metallotectons as the starting materials. These complexes show supramolecular architectures bonded by charge-assisted hydrogen bonds.« less

EVALUATION OF BENZO[C]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T1/2CL8 CELLS

EPA Science Inventory

EVALUATION OF BENZO[c]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T?CL8 CELLS

Abstract The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans-B[c]C-7,8-diol, trans-B[c]C-9...

(N-Benzyl-N-ethyl­dithio­carbamato)di-tert-butyl­chloridotin(IV)

PubMed Central

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R. T.

2011-01-01

The SnIV atom in the title diorganotin dithio­carbamate, [Sn(C4H9)2Cl(C10H12NS2)], is penta­coordinated by an asymmetrically coordinating dithio­carbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C2ClS2 donor set defines a coordination geometry inter­mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C—H⋯π contacts link centrosymmetrically related mol­ecules into dimeric aggregates. PMID:21522295

Automated M55 Detonator Production Equipment. Volume 1

DTIC Science & Technology

1987-05-01

i 41 •8 e o C u 01 o « v 01 & u a e. e < < •^ ec GO PI t^ r » fs o> ^ « •* ■ff w ■H cc...cl 4J C m e e u (0 0 9 e u « r o 4J u u 0 O CO X z e 09 I 1 6C 0) 4J c 09 C U •H •* 0 m •w W 0B U 01 IH 09 ■HOC...00 2 O CO 3 u -»^< r > 5 Q QTZQ + i m ^- ro 3ZtO O o ^ ’ O o UJO < Q: ui _i ou. M 0 s 0 u 01 T5 « M R « •? A s 3 9 IT»

Electrical conductivity of low-temperature NaCl-KCl-ZrCl4 melts

NASA Astrophysics Data System (ADS)

Salyulev, A. B.; Khokhlov, V. A.; Red'kin, A. A.

2014-08-01

The dependences of the electrical conductivity of NaCl-KCl-ZrCl4 molten mixtures with a molar ratio NaCl : KCl = 8 : 29 on the temperature (temperature range of 300-540°C) and the ZrCl4 concentration (54.3-75.2 mol %) have been measured for the first time using unique cells.

AFOSR (Air Force Office of Scientific Research) Technical Report Summaries, April-June 1984

DTIC Science & Technology

1984-06-01

tD LU (1) A CLf4’ 1 C Z -0 () CL4 U. IAc Z4 < u. C- ’ 0m u- 0 (A - 0- CEm 0 2 0is C U c. -u 4- u- 41 S0 (U 0 0 ~M MC *0 Wn 0 u Ci L C v LNo to 0. W U...A L NX4 ’A 0 L CL- *4 U) 0 . (~ -W 41 040 U .*- w~U M). or u0 th 0 0 0 W a L&.. , U)- 0 00 0 - 3UV ~V L 40 * 0. U) 41 (u mV 44 C a 0 CL co L8I Cl 9K...CU𔃼C~ 00 0C CL C 4’ TD W L 024 0󈧄.I CL9OC 02 u0 0 0. U. 4 C- - 3 L M04 M 02 L 41 ;.C M (0 S 0 Lb S0 0 ’W󈧺 W0) 0. -04 i- _.C 0 0’ to 0 00- 0- O -M

Intramolecular chalcogen-tin interactions in [(o-MeE-C6H4)CH2]2SnPh2-nCln; E = S, O, CH2, n = 0, 1, 2 and intermolecular chlorine-tin interactions in the meta and para-methoxy isomers

PubMed Central

Vargas-Pineda, Diana Gabriela; Guardado, Tanya; Cervantes-Lee, Francisco; Metta-Magana, Alejandro J.

2010-01-01

Organotin(IV) compounds of the type [(o-MeE-C6H4)CH2]2SnPh2-nCln were synthesized, E = O, n = 0 (1), n = 1 (2), n = 2 (3), E = S, n = 0 (4), n = 1 (5), n = 2 (6) and E = CH2, n = 0 (7), n = 1 (8), n = 2 (9). The dichloro compounds 3 and 6 have been investigated by single crystal X-ray diffraction and exhibit bi-capped tetrahedral geometry at the tin atom as a consequence of significant intramolecular Sn⋯O (3) and Sn⋯S (6) secondary bonding, in monomolecular units. Compound 3 when crystallized from a hexane/thf solvent mixture shows two different conformers, 3′ and 3″, in the crystal structure, 3′ has two equivalent Sn⋯O interactions, while 3″ has two non-equivalent Sn⋯O interactions. Upon recrystallization of 3 from hexane only a single structural form is observed, 3′. The Sn⋯E distances in 3′, 3″, and 6 are 71.3; 73.5, 72.9; and 76.3% of the ΣvdW radii, respectively. The meta and para-substituted isomers of 3 (10, 11) exhibit a distortion at the tin atom due to self-association via intermolecular Sn⋯Cl interactions resulting in polymeric structures. 119Sn NMR spectroscopy suggests that the intramolecular Sn⋯E interactions persist in solution for the dichloride compounds 3 and 6. PMID:20047301

Anti-MRSA-acting carbamidocyclophanes H-L from the Vietnamese cyanobacterium Nostoc sp. CAVN2.

PubMed

Preisitsch, Michael; Harmrolfs, Kirsten; Pham, Hang T L; Heiden, Stefan E; Füssel, Anna; Wiesner, Christoph; Pretsch, Alexander; Swiatecka-Hagenbruch, Monika; Niedermeyer, Timo H J; Müller, Rolf; Mundt, Sabine

2015-09-01

Correction to: The Journal of Antibiotics (2015) 68, 165–177; doi:10.1038/ja.2014.118, published online 3 September 2014. The authors noted errors upon publication of this article in the ‘Results and Discussion’ section. The molecular formulas presented for compounds 1–5 in the "Isolation procedure and structure elucidation" section are incorrect. These formulas should read as follows: 1. C37H57NO7 2. C37H56ClNO7 3. C38H56Cl2N2O8 4. C37H55Cl2NO7 5. C37H54Cl3NO7

Emerging Materials Technology in Japan

DTIC Science & Technology

1991-12-01

as an cfficlar 3eoanment of the Army positron . unless 50 desrgnated by orfrer authorized doctrmenn. blentlon of anv trade names or mXIUfaCTUref5... studied RF-plasma syntheses at atmospheric pres- sure, using mixtures of SiCl&H4 and H2 to produce cubic SIC with particle sizes in the 10 nm to 20...plasma method was studied by K. Akashi to produce beta SIC from an SiCl&Ha mixture carried in Hz. J. Hojo, H. Maeda, and A. Kato of Kyushu University pro

Impact of sample extraction on the accurate measurement of progesterone in human serum by liquid chromatography tandem mass spectrometry.

PubMed

Ke, Yuyong; Gonthier, Renaud; Labrie, Fernand

2017-05-01

In the present study, the impact of the extraction solvent on the accuracy of endogenous progesterone assay in human serum has been investigated using two selective reaction monitoring (SRM) transitions (315>97 & 315>109). Higher levels of noise and more interference were observed when more polar solvents were used for extraction, thus resulting in serious bias of the measured values of progesterone in serum. This is confirmed by monitoring the ion ratio of 315>97-315>109. This issue could not be easily resolved by changes in MS/MS transitions or chromatography conditions. More bias was observed with the SRM transition 315>109 for the polar solvent extraction. Hexane and 1-chlorobutane (polarity index of 0 and 1, respectively) did provide the cleanest samples with a lower noise level in the chromatograms. Moreover, the measured values of progesterone were not changed with different SRM transitions or longer retention time in search of an improved separation. Recovery tests of progesterone have been performed with 1-chlorobutane in matrices with phosphate buffered saline (PBS) 1x, PBS 1×3% bovine serum albumin (BSA), stripped serum/H 2 O (1:1) and unstripped serum. The recovery (70%∼80%) consistency is observed not only at different levels but also in different matrices. The equivalent recovery between PBS 1x, PBS 1×3% BSA and unstripped serum shows that the impact of progesterone binding to serum proteins on the measurement accuracy can be avoided with this sample preparation procedure. No significant matrix effect on the determination of progesterone was observed with 1-chlorobutane. Within the range of 12.5-2000pg/mL, a good linearity is observed with R>0.99 and weighting factor 1/X. Bias and covariance efficiency of QCs are within 10%. With 1-chlorobutane as the extraction solvent, the concentration of progesterone was measured where the range for postmenopausal serum is 5.74∼91.7pg/mL, which is well below the reported concentrations of 314 pg/mL∼942pg/mL in postmenopausal serum by immunoassay-based techniques, while the range in premenopausal serum is 12.8 pg/mL∼18.6ng/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of hCG administration during corpus luteum establishment on subsequent corpus luteum development and circulating progesterone concentrations in beef heifers.

PubMed

Maillo, V; Duffy, P; O'Hara, L; de Frutos, C; Kelly, A K; Lonergan, P; Rizos, D

2014-03-01

This study examined the effect of a single administration of human chorionic gonadotrophin (hCG) on Day 1 to 4 after oestrus on corpus luteum (CL) development and circulating progesterone (P4). Oestrus-synchronized heifers (n=43) were administered a single intramuscular injection of saline on Day 1 (control) or 3000IU hCG on Day 1, 2, 3 or 4 after oestrus. Administration of hCG on Day 1 had no effect on CL area, on Day 2 increased CL area from Day 6 to 12 (P<0.05), on Day 3 increased CL area from Day 9 to 11, while on Day 4 increased CL size on Days 9 and 10 (P<0.05). Administration of hCG on Day 4 induced the formation of an accessory CL in 89% of heifers, resulting in a significant increase in total luteal tissue area on the ovaries compared with all other groups. Consistent with the effects on the CL, hCG on Day 1 did not affect P4 concentrations, on Day 2 significantly increased P4 compared with the control from Day 6 to 11 (P<0.05), on Day 3 resulted in a non-significant increase in P4 while hCG on Day 4 increased P4 from Day 8 to 13 compared with the control (P<0.05). In conclusion, administration of hCG as early as Day 2 after oestrus results in increased P4 in circulation from Day 6, which should have beneficial downstream effects in terms of uterine receptivity and conceptus elongation.

New molecular assemblies of redox isomers, [CrIII(X4SQ)3-n(X4Cat)n]-n (X = Cl and Br; n = 0, 1, and 2), with metallocenium cations, [MIIICp2]+ (M = Co and Fe): X-ray crystal structures and physical properties.

PubMed

Chang, H C; Miyasaka, H; Kitagawa, S

2001-01-01

A series of redox isomers of [CrIII(X4SQ)(X4Cat)2]2-, [CrIII(X4SQ)2(X4Cat)]-, and [CrIII(X4SQ)3]0 (X = Cl and Br, SQ = semiquinonate, and Cat = catecholate) have been synthesized and characterized as charge-transfer (CT) compounds with metallocenium cations: (CoIIICp2)2[CrIII(Cl4SQ)(Cl4Cat)2] (1), (CoIIICp2)2[CrIII(Br4SQ)(Br4Cat)2] (2), (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (4), (FeIIICp2)[CrIII(Br4SQ)2(Br4Cat)].CS2 (5), and (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)][CrIII(Cl4SQ)3] (6). First, the oxidation states of the chromium complexes are strongly dependent on the redox potentials of the metallocenes used. The CoIICp2, exhibiting stronger reduction power than FeIICp2, is useful for two-electron reduction of the [CrIII(X4SQ)3]0, affording [CrIII(X4SQ)(X4Cat)2]2- (1 and 2), which are first isolated and crystallographically characterized in the solid state. In contrast the reaction with FeIICp2 affords only [CrIII(X4SQ)2(X4Cat)]- (4 and 5). Second, solvents influence crystal structures of these compounds. The solvent set of C6H6/CS2 gives 1:1:C6H6 compound 4 with unique charged anions, [CrIII(Cl4SQ)2(Cl4Cat)]-, while the other set, n-C6H12/CS2, affords 1:2 compound 6 including the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0. The [CrIII(X4SQ)(X4Cat)2]2- anions in 1 and 2 show no significant interconnection between them (discrete type), while the [CrIII(X4SQ)2(X4Cat)]- anions in 4-6 show one-dimensional column-type structures with the aid of intermolecular stacking interactions of the ligand moieties. The anions in 4 show additional stacking interaction with the [FeIIICp2]+ to form one-dimensional ...[D][A][S][D][A]... (D = [FeIIICp2]+, A = [CrIII(Cl4SQ)2(Cl4Cat)]-, and S = C6H6) type mixed-stack arrangements similar to that of previously reported (CoIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (3). Compound 6 forms a two-dimensional sheet structure where the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0, are included. The sheet is regarded as a mixed-valence molecular assembly. Two types of the anions, [CrIII(X4SQ)(X4Cat)2]2- (1 and 2) and [CrIII(X4SQ)2(X4Cat)]- (4-6), exhibiting an intramolecular mixed-valence state, show intramolecular intervalence CT transition (IVCT) from the Cat to the SQ at near 5800 and 4300 cm-1, respectively, both in the solution and in the solid states. The intermolecular mixed-valence state of 6 was characterized by absorption spectroscopy, electric conductivity, and SQUID magnetometry. Interestingly, this mixed-valence state of the chromium module is dependent on the redox active nature of the coordinated ligands.

Factors influencing inactivation of Klebsiella pneumoniae by chlorine and chloramine.

PubMed

Goel, Sudha; Bouwer, Edward J

2004-01-01

Inactivation of Klebsiella pneumoniae cultures by chlorine and chloramine was evaluated under different growth conditions by varying nutrient media dilution, concentrations of essential inorganic nutrients (FeCl3, MgSO4, phosphate, and ammonium salts), and temperature. All inactivation assays were performed at room temperature (22-23 degrees C) and near neutral pH (7.2-7.5). C*T(99.9) values for chlorine increased >20-fold and for chloramine increased 2.6-fold when cells were grown in 100-fold diluted nutrient broth (2NB) solutions (final TOC of 35-40 mg/L). Background levels of Mg: 6.75 x 10(-2) mM and Fe: 3.58 x 10(-5) mM or high levels of FeCl3 (0.01 mM) and MgSO4 (1 mM) during growth resulted in the highest resistances to chlorine with C*T(99.9) values of 13.06 (+/-0.91) and 13.78 (+/-1.97) mg-min/L, respectively. Addition of low levels of FeCl3 (0.001 mM) and MgSO4 (0.1 mM) to K. pneumoniae cultures during growth resulted in the lowest bacterial resistances to inactivation; C*T(99.9) values ranged from 0.28 (+/-0.06) to 1.88 (+/-0.53)mg-min/L in these cultures. Increase in growth temperature from 22.5 degrees C to 35 degrees C for unamended 2NB cultures resulted in a 42-fold decrease in C*T(99.9) values for chlorine. A similar change in temperature resulted in no significant change in C*T(99.9) values for chloramine. These results indicate that inactivation of K. pneumoniae cultures by chlorine was highly sensitive to changes in growth conditions unlike inactivation by chloramine.

Heterogeneous Reaction of ClONO2(g) + NaCl(s) to Cl2(g) + NaNO3(s)

NASA Technical Reports Server (NTRS)

Timonen, Raimo S.; Chu, Liang T.; Leu, Ming-Taun; Keyser, Leon F.

1994-01-01

The heterogeneous reaction of ClON02 + NaCl yields Cl2 + NaNO3 (eq 1) was investigated over a temperature range 220-300 K in a flow-tube reactor interfaced with a differentially pumped quadrupole mass spectrometer. Partial pressures of ClON02 in the range 10(exp -8) - 10(exp -5) Torr were used. Granule sizes and surface roughness of the NaCl substrates were determined by using a scanning electron microscope, and in separate experiments, surface areas of the substrates were measured by using BET analysis of gas-adsorption isotherms. For dry NaCl substrates, both the decay rates of ClON02 and the growth rates Of C12 were used to obtain reaction probabilities, gamma(sub l) = (4.6 +/- 3.0) x 10(exp -3) at 296 K and (6.7 +/- 3.2) x 10(exp -1) at 225 K, after considering the internal surface area, The error bars represent 1 standard deviation. The Cl2 yield based on the ClONO2 reacted was measured to be 1.0 +/- 0.2. In order to mimic the conditions encountered in the lower stratosphere, the effect of water vapor pressures between 5 x 10(exp -5) and 3 x 10(exp -4) Torr on reaction 1 was also studied. With added H20, reaction probabilities, gamma = (4.1 +/- 2.1) x 10(exp -3) at 296 K and (4.7 +/- 2.9) x 10(exp -3) at 225 K, were obtained. A trace of HOCl, the reaction product from the ClON02 + H20 yield HOCl + HN03 reaction, was observed in addition to the C12 product from reaction 1. The implications of this result for the enhancement of hydrogen chloride in the stratosphere after the El Chichon volcanic eruption and for the marine troposphere are discussed.

Inhibition of Clostridium perfringens spore germination and outgrowth by lemon juice and vinegar product in reduced NaCl roast beef.

PubMed

Li, Lin; Valenzuela-Martinez, Carol; Redondo, Mauricio; Juneja, Vijay K; Burson, Dennis E; Thippareddi, Harshavardhan

2012-11-01

Inhibition of Clostridium perfringens spore germination and outgrowth in reduced sodium roast beef by a blend of buffered lemon juice concentrate and vinegar (MoStatin LV1) during abusive exponential cooling was evaluated. Roast beef containing salt (NaCl; 1%, 1.5%, or 2%, w/w), blend of sodium pyro- and poly-phosphates (0.3%), and MoStatin LV1 (0%, 2%, or 2.5%) was inoculated with a 3-strain C. perfringens spore cocktail to achieve final spore population of 2.5 to 3.0 log CFU/g. The inoculated products were heat treated and cooled exponentially from 54.4 to 4.4 °C within 6.5, 9, 12, 15, 18, or 21 h. Cooling of roast beef (2.0% NaCl) within 6.5 and 9 h resulted in <1.0 log CFU/g increase in C. perfringens spore germination and outgrowth, whereas reducing the salt concentration to 1.5% and 1.0% resulted in >1.0 log CFU/g increase for cooling times longer than 9 h (1.1 and 2.2 log CFU/g, respectively). Incorporation of MoStatin LV1 into the roast beef formulation minimized the C. perfringens spore germination and outgrowth to <1.0 log CFU/g, regardless of the salt concentration and the cooling time. Cooked, ready-to-eat meat products should be cooled rapidly to reduce the risk of Clostridium perfringens spore germination and outgrowth. Meat processors are reducing the sodium chloride content of the processed meats as a consequence of the dietary recommendations. Sodium chloride reduces the risk of C. perfringens spore germination and outgrowth in meat products. Antimicrobials that contribute minimally to the sodium content of the product should be incorporated into processed meats to assure food safety. Buffered lemon juice and vinegar can be incorporated into meat product formulations to reduce the risk of C. perfringens spore germination and outgrowth during abusive cooling. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

Thermal inactivation of acid, cold, heat, starvation, and desiccation stress-adapted Escherichia coli O157:H7 in moisture-enhanced nonintact beef.

PubMed

Shen, Cangliang; Geornaras, Ifigenia; Belk, Keith E; Smith, Gary C; Sofos, John N

2011-04-01

This study was conducted to compare thermal inactivation of stress-adapted and nonadapted Escherichia coli O157:H7 in nonintact beef moisture enhanced with different brine formulations and cooked to 65°C. Coarsely ground beef was mixed with acid, cold, heat, starvation, or desiccation stress-adapted or nonadapted rifampin-resistant E. coli O157:H7 (eight-strain mixture, 5 to 6 log CFU/g) and a brine solution for a total moisture enhancement level of 10%. The brine treatments included distilled water (control), sodium chloride (0.5% NaCl) plus sodium tripolyphosphate (0.25% STP), or NaCl + STP combined with cetylpyridinium chloride (0.2% CPC), lactic acid (0.3% LA), or sodium metasilicate (0.2% SM). The treated meat was extruded into bags (15 cm diameter), semifrozen (-20°C for 4.5 h), and cut into 2.54-cm (1-in.)-thick portions. Samples were individually vacuum packaged, frozen (-20°C for 42 h), and tempered at 4°C for 2.5 h before cooking. Partially thawed (-1.8 ± 0.4°C) samples were pan broiled to an internal temperature of 65°C. Pathogen counts of partially thawed (before cooking) samples moisture enhanced with brines containing CPC, LA, or SM were 0.7 to 1.1, 0.0 to 0.4, and 0.2 to 0.4 log CFU/g, respectively, lower than those of the control. Compared with microbial count reductions obtained after pan broiling of beef inoculated with nonadapted E. coli O157:H7 cells, count reductions during cooking of meat inoculated with cold and desiccation stress-adapted, acid stress-adapted, and heat and starvation stress-adapted cells indicated sensitization, cross protection, and no effect, respectively, of these stresses on the pathogen during subsequent exposure to heat. Among all stressed cultures, CPC-treated samples (0.8 to 3.6 log CFU/g) and LA-treated samples (0.8 to 3.5 log CFU/g) had the lowest numbers of E. coli O157:H7 survivors after cooking.

Free Radical Production from the Interaction of 2-Chloroethyl Vesicants (Mustard Gas) with Pyridine Nucleotide-Driven Flavoprotein Electron Transport Systems

DTIC Science & Technology

2009-01-01

or HN2 at desired mM levels and 2.4 mM NADPH were introduced with 40 µM cytochrome c in 0.1 M KPO4 buffer pH 7.5 made 0.25 M with respect to NaCl. The...because 4-POBN is a nitrone , the adduct formed occurred at the carbon adjacent to the imino nitrogen of the spin trap, too many bonds distant from...EPR spectrometry with spin trapping. Inclusion of the nitrone 4-POBN in our incubation mixture at the molar level enabled us to observe a six-line 4

Changes in the geometries of C₂H₂ and C₂H₄ on coordination to CuCl revealed by broadband rotational spectroscopy and ab-initio calculations.

PubMed

Stephens, Susanna L; Bittner, Dror M; Mikhailov, Victor A; Mizukami, Wataru; Tew, David P; Walker, Nicholas R; Legon, Anthony C

2014-10-06

The molecular geometries of isolated complexes in which a single molecule of C2H4 or C2H2 is bound to CuCl have been determined through pure rotational spectroscopy and ab-initio calculations. The C2H2···CuCl and C2H4···CuCl complexes are generated through laser vaporization of a copper rod in the presence of a gas sample undergoing supersonic expansion and containing C2H2 (or C2H4), CCl4, and Ar. Results are presented for five isotopologues of C2H2···CuCl and six isotopologues of C2H4···CuCl. Both of these complexes adopt C(2v), T-shaped geometries in which the hydrocarbon binds to the copper atom through its π electrons such that the metal is equidistant from all H atoms. The linear and planar geometries of free C2H2 and C2H4, respectively, are observed to distort significantly on attachment to the CuCl unit, and the various changes are quantified. The ∠(*-C-H) parameter in C2H2 (where * indicates the midpoint of the C≡C bond) is measured to be 192.4(7)° in the r0 geometry of the complex representing a significant change from the linear geometry of the free molecule. This distortion of the linear geometry of C2H2 involves the hydrogen atoms moving away from the copper atom within the complex. Ab-initio calculations at the CCSD(T)(F12*)/AVTZ level predict a dihedral ∠(HCCCu) angle of 96.05° in C2H4···CuCl, and the experimental results are consistent with such a distortion from planarity. The bonds connecting the carbon atoms within each of C2H2 and C2H4, respectively, extend by 0.027 and 0.029 Å relative to the bond lengths in the isolated molecules. Force constants, k(σ), and nuclear quadrupole coupling constants, χ(aa)(Cu), [χ(bb)(Cu) - χ(cc)(Cu)], χ(aa)(Cl), and [χ(bb)(Cl) - χ(cc)(Cl)], are independently determined for all isotopologues of C2H2···CuCl studied and for four isotopologues of C2H4···CuCl.

Magnetic resonances in perovskite-type layer structures

NASA Astrophysics Data System (ADS)

Strobel, K.; Geick, R.

1981-08-01

We have studied the q=0 magnetic excitations of the perovskite-type layer structures A 2MnCl 4 with A=Rb, C nH 2n+1NH 3 (n=1,2,3), and NH 3(CH 2) mNH 3MnCl 4 (m=2,4,5) in the antiferromagnetic and in the spin flop regime by means of magnetic resonance in the mm-wave range (30-130GHz) and microwave range (9.2GHz). The length of the organic molecules determines the separation of the MnCl 6 octahedra. With increasing separation the Néel temperature and the antiferromagnetic resonance frequency decrease, which mainly originates from a decrease of the anisotropy field.

Structure and vibrational spectra of pyridine betaine hydrochloride

NASA Astrophysics Data System (ADS)

Szafran, Mirosław; Koput, Jacek; Baran, Jan; Głowiak, Tadeusz

1997-12-01

The crystal structure of pyridine betaine hydrochloride (PBET·HCl) was determined by X-ray diffraction to be monoclinic, space group {P2 1}/{c} with a = 8.533(2) Å, b = 9.548(2) Å, c = 10.781(2) Å, β = 107.228(3)° and Z = 4. Betaine is protonated and the carboxyl group forms a hydrogen bond with the chloride ion: O·Cl - distance is 2.928(3) Å. The interaction of pyridine betaine (PBET) with HCl was examined by ab initio self-consistent field (SCF), second-order Møller-Plesset (MP2) and density functional theory (DFT) methods using the 6-31G(d,p) basis set. Two minima are located in the potential surface at the SCF level (PBETH +·Cl - and PBET·HCl, with the latter being 1.2 kcal mol -1 lower in energy) and only one minimum (PBET·HCl) at the MP2 and DFT levels. The molecular parameters of PBETH +·Cl -, computed by the SCF method, reproduce the corresponding experimental data. The computed vibrational frequencies of PBETH +·Cl - resemble correctly the experimental vibrational spectrum in the solid state. The root-mean-square (r.m.s.) deviations between the experimental and calculated SCF frequencies are 65 cm -1 for all bands and 15 cm -1 without the νClH band. All measured IR bands were interpreted in terms of the calculated vibrational models.

NHC→SiCl4 : an ambivalent carbene-transfer reagent.

PubMed

Böttcher, Tobias; Steinhauer, Simon; Lewis-Alleyne, Lesley C; Neumann, Beate; Stammler, Hans-Georg; Bassil, Bassem S; Röschenthaler, Gerd-Volker; Hoge, Berthold

2015-01-07

The addition of BCl3 to the carbene-transfer reagent NHC→SiCl4 (NHC=1,3-dimethylimidazolidin-2-ylidene) gave the tetra- and pentacoordinate trichlorosilicon(IV) cations [(NHC)SiCl3 ](+) and [(NHC)2 SiCl3 ](+) with tetrachloroborate as counterion. This is in contrast to previous reactions, in which NHC→SiCl4 served as a transfer reagent for the NHC ligand. The addition of BF3 ⋅OEt2 , on the other hand, gave NHC→BF3 as the product of NHC transfer. In addition, the highly Lewis acidic bis(pentafluoroethyl)silane (C2 F5 )2 SiCl2 was treated with NHC→SiCl4 . In acetonitrile, the cationic silicon(IV) complexes [(NHC)SiCl3 ](+) and [(NHC)2 SiCl3 ](+) were detected with [(C2 F5 )SiCl3 ](-) as counterion. A similar result was already reported for the reaction of NHC→SiCl4 with (C2 F5 )2 SiH2 , which gave [(NHC)2 SiCl2 H][(C2 F5 )SiCl3 ]. If the reaction medium was changed to dichloromethane, the products of carbene transfer, NHC→Si(C2 F5 )2 Cl2 and NHC→Si(C2 F5 )2 ClH, respectively, were obtained instead. The formation of the latter species is a result of chloride/hydride metathesis. These compounds may serve as valuable precursors for electron-poor silylenes. Furthermore, the reactivity of NHC→SiCl4 towards phosphines is discussed. The carbene complex NHC→PCl3 shows similar reactivity to NHC→SiCl4 , and may even serve as a carbene-transfer reagent as well. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new metal-organic framework for separation of C2H2/CH4 and CO2/CH4 at room temperature

NASA Astrophysics Data System (ADS)

Duan, Xing; Zhou, You; Lv, Ran; Yu, Ben; Chen, Haodong; Ji, Zhenguo; Cui, Yuanjing; Yang, Yu; Qian, Guodong

2018-04-01

A 3D microporous metal-organic framework with open Cu2+ sites and suitable pore space, [Cu2(L)(H2O)2]·(H2O)4(DMF)8 (ZJU-15, H4L = 5,5‧-(9H-carbazole-2,7-diyl)diisophthalic acid; DMF = N,N-dimethylformamide; ZJU = Zhejiang University), has been constructed and characterized. The activated ZJU-15a has three different types of cages and exhibits BET surface area of 1660 m2 g-1, and can separate gas mixture of C2H2/CH4 and CO2/CH4 at room temperature.

Amino Compounds as Inhibitors of De Novo Synthesis of Chlorobenzenes

NASA Astrophysics Data System (ADS)

Wang, Si-Jia; He, Pin-Jing; Lu, Wen-Tao; Shao, Li-Ming; Zhang, Hua

2016-04-01

The inhibitory effects of four amino compounds on the formation of chlorobenzenes (CBzs) - dioxin precursors and indicators, and the inhibitory mechanisms were explored. The results show NH4H2PO4 can decrease the total yields of CBzs (1,2di-CBz, 1,3di-CBz, 1,4di-CBz, penta-CBz and hexa-CBz) by 98.1%±1.6% and 96.1%±0.7% under air and nitrogen flow. The inhibitory effects indicated by the total yields of CBzs follow the order NH4H2PO4 > NH4HF2 > (NH4)2SO4 > NH4Br under air flow and NH4H2PO4 ≈ (NH4)2SO4 ≈ NH4HF2 >NH4Br under nitrogen flow. The inhibition mechanism revealed by thermal analysis that CuCl2 was converted to CuPO3 by reacting with NH4H2PO4 below 200 °C, which can block the transfer of chlorine and formation of C-Cl bonds at 350 °C. The effects of the other three inhibitors were weaker because their reactions with CuCl2, which form other copper compounds, and the reaction of CuCl2 with carbon, which forms C-Cl bonds, were almost simultaneous and competitive. Oxygen influenced the yield of CBzs obviously, and the total yield of five CBzs sharply increased with oxygen. Because of their high efficiency, low environmental impact, low cost, and availability, amino compounds - especially NH4H2PO4 - can be utilized as inhibitors of CBzs during incineration.

Crystal structure of cis-di­chlorido­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N)chromium(III) (oxalato-κ2 O 1,O 2)(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N)chromium(III) bis(perchlorate) from synchrotron data

PubMed Central

Moon, Dohyun; Choi, Jong-Ha

2016-01-01

In the asymmetric unit of the title compound, [CrCl2(C10H24N4)][Cr(C2O4)(C10H24N4)](ClO4)2 (C10H24N4 = 1,4,8,11-tetra­aza­cyclo­tetra­decane, cyclam; C2O4 = oxalate, ox), there are two independent halves of the [CrCl2(cyclam)]+ and [Cr(ox)(cyclam)]+ cations, and one perchlorate anion. In the complex cations, which are completed by application of twofold rotation symmetry, the CrIII ions are coordinated by the four N atoms of a cyclam ligand, and by two chloride ions or one oxalate bidentate ligand in a cis arrangement, displaying an overall distorted octa­hedral coordination environment. The Cr—N(cyclam) bond lengths are in the range of 2.075 (5) to 2.096 (4) Å while the Cr—Cl and Cr—O(ox) bond lengths are 2.3358 (14) and 1.956 (4) Å, respectively. Both cyclam moieties adopt the cis-V conformation. The slightly distorted tetra­hedral ClO4 − anion remains outside the coordination sphere. The supra­molecular architecture includes N—H⋯O and N—H⋯Cl hydrogen bonding between cyclam NH donor groups, O atoms of the oxalate ligand or ClO4 − anions and one Cl ligand as acceptors, leading to a three-dimensional network structure. PMID:27746932

Haloanaerobium salsugo sp. nov., a moderately halophilic, anaerobic bacterium from a subterranean brine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhupathiraju, V.K.; Sharma, P.K.; Tanner, R.S.

A strictly anaerobic, moderately halophilic, gram-negative bacterium was isolated from a highly saline oil field brine. The bacterium was a non-spore-forming, nonmotile rod, appearing singly, in pairs, or occasionally as long chains, and measured 0.3 to 0.4 by 2.6 to 4 {micro}m. The bacterium had a specific requirement for NaCl and grew at NaCl concentrations of between 6 and 24%, with optimal growth at 9% NaCl. The isolate grew at temperatures of between 22 and 51 C and pH values of between 5.6 and 8.0. The doubling time in a complex medium containing 10% NaCl was 9 h. Growth wasmore » inhibited by chloramphenicol, tetracycline, and penicillin but not by cycloheximide or azide. Fermentable substrates were predominantly carbohydrates. The end products of glucose fermentation were acetate, ethanol, CO{sub 2}, and H{sub 2}. The major components of the cellular fatty acids were C{sub 14:0}, C{sub 16:0}, C{sub 16:1}, and C{sub 17:0 cyc} acids. The DNA base composition of the isolate was 34 mol% G+C. Oligonucleotide catalog and sequence analyses of the 16S rRNA showed that strain VS-752{sup T} was most closely related to Haloanaerobium praevalens GSL{sup T} (ATCC 33744), the sole member of the genus Haloanaerobium. The authors propose that strain VS-752 (ATCC 51327) by established as the type strain of a new species, Haloanaerobium salsugo, in the genus Haloanaerobium. 40 refs., 3 figs, 5 tabs.« less

Labeling and Biological Evaluation of (99m)Tc-HYNIC-Trastuzumab as a Potential Radiopharmaceutical for In Vivo Evaluation of HER2 Expression in Breast Cancer.

PubMed

Calzada, Victoria; Garcia, Fernanda; Fernández, Marcelo; Porcal, Williams; Quinn, Thomas; Alonso, Omar; Gambini, Juan Pablo; Cabral, Pablo

2013-01-01

The amplification of HER2 gene has been described in several tumor types, mainly breast cancer with a subsequent increase in HER2 protein expression. Trastuzumab is a humanized monoclonal antibody that recognizes selectively the HER2 extracellular domain. The objective of the present work was to standardize the conjugation of Trastuzumab with Succinimidyl-hydrazinonicotinamide (HYNIC) and labeling with (99m)Tc to obtain (99m)Tc-HYNIC-Trastuzumab for use as in vivo tracer of the HER2 expression in breast cancer. The labeling procedure involved derivatization of 0.067 μmol of Trastuzumab with 0.33 μmols of HYNIC in dimethyl sulfoxide (DMSO). The mixture was incubated for 30 min. A mixture of Tricine and SnCl2.2H2O was prepared by add a solution of 44.6 μmols Tricine in 0.05 mL HCl 2.0 M and a similar volume of another solution containing 44.3 μmols SnCl2.2H2O in 0.5 mL HCl 2.0 M. Then, 0.05 mL of this mixed was added to the conjugated with 296 MBq of 99mTcO-4. The final mixture was incubated at room temperature (18-25°C) for 30 min. Radiochemical purity of the labeled solution was studied by chromatography, to evaluate (99m)Tc-Tricine, (99m)TcO2.H2O, and free (99m)TcO4 (-). Radiochemical purity was also evaluated by HPLC. Stability studies were tested in solution at 4°C and lyophilized at 4°C. Biodistribution studies were performed in healthy CD-1 female mice at 2, 5, and 24 h (n = 3) and CD-1 female mice spontaneous breast adenocarcinoma (n = 3). Scintigraphic images of spontaneous breast adenocarcinoma in female CD-1 mice were acquired in a gamma camera at 2, 5, and 24 h post-injection. Labeling was easily performed with high yields (>90%) and radiopharmaceutical stability for 24 h post-labeling. Stability studies revealed that antibody derivative must be lyophilized for undamaged storage. Biodistribution studies and imaging revealed excellent uptake in the tumor. Based on the results it was concluded that (99m)Tc-HYNIC-Trastuzumab could be a promising radiopharmaceutical for in vivo diagnosis of the HER2 status in breast with impact on treatment planning.

Single Crystal Epitaxy and Characterization of Beta-SiC.

DTIC Science & Technology

1982-07-01

and CH4 (35, 40), SiC] 4 and C3H8 (40-43), SiCl4 and C6H6 (37), SiCl4 and C7H8 (37, 44), and SiC]4 and CCI 4 (45-47). In all cases, the carrier gas...crystal layer on top of the as-formed 8-SiC substrate. Their problem may arise from the use of the gas combination of SiCl4 and CCI 4, because still...falling between those for the CH4- and the C2H4-c-ritaining systems. (4) The SiCl4 /CCI4/H2 System The species considered to be in the gaseous phase of

Cyclometalated products of [(COE)(2)RhCl](2) and 1,3-(RSCH(2))(2)C(6)H(4) (R = (t)Bu, (i)Pr) Are Dimeric. Synthesis, molecular structures, and solution dynamics of [mu-ClRh(H)(RSCH(2))(2)C(6)H(3)-2,6](2).

PubMed

Evans, Daniel R; Huang, Mingsheng; Seganish, W Michael; Chege, Esther W; Lam, Yiu-Fai; Fettinger, James C; Williams, Tracie L

2002-05-20

Two tridentate thioether pincer ligands, 1,3-(RSCH(2))(2)C(6)H(4) (R = (t)()Bu, 1a; R = (i)()Pr, 1b) underwent cyclometalation using [(COE)(2)RhCl](2) in air/moisture-free benzene at room temperature. The resultant complexes, [mu-ClRh(H)(RSCH(2))(2)C(6)H(3)-2,6](2) (R = (t)Bu, 2a; R = (i)Pr, 2b) are dimeric both in the solid state and in solution. A battery of variable-temperature one- and two-dimensional (1)H NMR experiments showed conclusively that both complexes undergo dynamic exchange in solution. Exchange between two dimeric diastereomers of 2a in solution occurred via rotation about the Rh-C(ipso) bond. The dynamic exchange of 2b was significantly more complex as an additional exchange mechanism, sulfur inversion, occurred, which resulted in the exchange between several diastereomers in solution.

Use of a single trajectory to study product energy partitioning in unimolecular dissociation: mass effects for halogenated alkanes.

PubMed

Sun, Lipeng; Park, Kyoyeon; Song, Kihyung; Setser, Donald W; Hase, William L

2006-02-14

A single trajectory (ST) direct dynamics approach is compared with quasiclassical trajectory (QCT) direct dynamics calculations for determining product energy partitioning in unimolecular dissociation. Three comparisons are made by simulating C(2)H(5)F-->HF + C(2)H(4) product energy partitioning for the MP26-31G(*) and MP26-311 + + G(**) potential energy surfaces (PESs) and using the MP26-31G(*) PES for C(2)H(5)F dissociation as a model to simulate CHCl(2)CCl(3)-->HCl + C(2)Cl(4) dissociation and its product energy partitioning. The trajectories are initiated at the transition state with fixed energy in reaction-coordinate translation E(t) (double dagger). The QCT simulations have zero-point energy (ZPE) in the vibrational modes orthogonal to the reaction coordinate, while there is no ZPE for the STs. A semiquantitative agreement is obtained between the ST and QCT average percent product energy partitionings. The ST approach is used to study mass effects for product energy partitioning in HX(X = F or Cl) elimination from halogenated alkanes by using the MP26-31G(*) PES for C(2)H(5)F dissociation and varying the masses of the C, H, and F atoms. There is, at most, only a small mass effect for partitioning of energy to HX vibration and rotation. In contrast, there are substantial mass effects for partitioning to relative translation and the polyatomic product's vibration and rotation. If the center of mass of the polyatomic product is located away from the C atom from which HX recoils, the polyatomic has substantial rotation energy. Polyatomic products, with heavy atoms such as Cl atoms replacing the H atoms, receive substantial vibration energy that is primarily transferred to the wag-bend motions. For E(t) (double dagger) of 1.0 kcalmol, the ST calculations give average percent partitionings to relative translation, polyatomic vibration, polyatomic rotation, HX vibration, and HX rotation of 74.9%, 6.8%, 1.5%, 14.4%, and 2.4% for C(2)H(5)F dissociation and 39.7%, 38.1%, 0.2%, 16.1%, and 5.9% for a model of CHCl(2)CCl(3) dissociation.

Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [clln(sch2(co)o)2]2-[(4-mepyh)2]2+

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K.; Duraj, Stan A.; Fanwick, Philip E.; Hepp, Aloysius F.; Martock, Robert A.

2004-01-01

The synthesis and structural characterization of a novel In(III) complex is described. The reaction between InCl3 with sodium mercapto-acetic acid, (NaSCH2(CO)OH) in 4-methylpyridine, (CH3(C5H5N), (4-Mepy)) at 25 C affords [ClIn(SCH2(CO)O)2]2- [(4-MepyH)2]2+. X-ray diffraction studies show it to have a distorted square pyramidal geometry, with the [(-SCH2(CO)CO-)] ligands in a trans conformation. The compound crystallizes in the P(raised dash) 1 (No. 2) space group with a = 7.8624 Angstrom, b = 9.950 Angstrom, c = 13.793 Angstrom, alpha = 107.60 degrees, beta= 90.336 degrees, gamma = 98.983 degrees, V = 1014.3 Angstroms (sup 3), R(F(raised circle)) = 0.037, and R(sub w) = 0.048.

Synthesis, molecular structure, and C-C coupling reactions of carbeneruthenium(II) complexes with C5H5Ru(=CRR') and C5Me5Ru(=CRR') as molecular units.

PubMed

Braun, Thomas; Münch, Gerhard; Windmüller, Bettina; Gevert, Olaf; Laubender, Matthias; Werner, Helmut

2003-06-06

The ethene derivatives [(eta(5)-C(5)R(5))RuX(C(2)H(4))(PPh(3))] with R=H and Me, which have been prepared from the eta(3)-allylic compounds [(eta(5)-C(5)R(5))Ru(eta(3)-2-MeC(3)H(4))(PPh(3))] (1, 2) and acids HX under an ethene atmosphere, are excellent starting materials for the synthesis of a series of new halfsandwich-type ruthenium(II) complexes. The olefinic ligand is replaced not only by CO and pyridine, but also by internal and terminal alkynes to give (for X=Cl) alkyne, vinylidene, and allene compounds of the general composition [(eta(5)-C(5)R(5))RuCl(L)(PPh(3))] with L=C(2)(CO(2)Me)(2), Me(3)SiC(2)CO(2)Et, C=CHCO(2)R, and C(3)H(4). The allenylidene complex [(eta(5)-C(5)H(5))RuCl(=C=C=CPh(2))(PPh(3))] is directly accessible from 1 (R=H) in two steps with the propargylic alcohol HC triple bond CC(OH)Ph(2) as the precursor. The reactions of the ethene derivatives [(eta(5)-C(5)H(5))RuX(C(2)H(4))(PPh(3))] (X=Cl, CF(3)CO(2)) with diazo compounds RR'CN(2) yield the corresponding carbene complexes [(eta(5)-C(5)R(5))RuX(=CRR')(PPh(3))], while with ethyl diazoacetate (for X=Cl) the diethyl maleate compound [(eta(5)-C(5)H(5))RuCl[eta(2)-Z-C(2)H(2)(CO(2)Et)(2)](PPh(3))] is obtained. Halfsandwich-type ruthenium(II) complexes [(eta(5)-C(5)R(5))RuCl(=CHR')(PPh(3))] with secondary carbenes as ligands, as well as cationic species [(eta(5)-C(5)H(5))Ru(=CPh(2))(L)(PPh(3))]X with L=CO and CNtBu and X=AlCl(4) and PF(6), have also been prepared. The neutral compounds [(eta(5)-C(5)H(5))RuCl(=CRR')(PPh(3))] react with phenyllithium, methyllithium, and the vinyl Grignard reagent CH(2)=CHMgBr by displacement of the chloride and subsequent C-C coupling to generate halfsandwich-type ruthenium(II) complexes with eta(3)-benzyl, eta(3)-allyl, and substituted olefins as ligands. Protolytic cleavage of the metal-allylic bond in [(eta(5)-C(5)H(5))Ru(eta(3)-CH(2)CHCR(2))(PPh(3))] with acetic acid affords the corresponding olefins R(2)C=CHCH(3). The by-product of this process is the acetato derivative [(eta(5)-C(5)H(5))Ru(kappa(2)-O(2)CCH(3))(PPh(3))], which can be reconverted to the carbene complexes [(eta(5)-C(5)H(5))RuCl(=CR(2))(PPh(3))] in a one-pot reaction with R(2)CN(2) and Et(3)NHCl.

Chemical vapor deposition of yttria-stabilized zirconia as a thermal barrier coating for gas turbine engines

NASA Astrophysics Data System (ADS)

Varanasi, Venu Gopal

The gas turbine engine uses an yttria-stabilized zirconia (YSZ) coating to provide thermal insulation for its turbine blades. This YSZ coating must be tetragonal in crystal structure, columnar in microstructure, and be 100--250 mum thick to provide for adequate protection for the turbine blades in the severe engine environment. Currently, YSZ coatings are fabricated by electron-beam physical vapor deposition (EB-PVD), but this fabrication method is cost intensive. Chemical vapor deposition (CVD) is a more commercially viable processing method and a possible alternative to EB-PVD. The deposition of tetragonal YSZ from gaseous metal and oxidation sources were studied. A chemical equilibrium analysis modeled the feasibility of depositing tetragonal YSZ for both chloride CVD (Zr-Y-C-O-Cl-H-Inert system) and metal-organic CVD (MOCVD) (Zr-Y-C-O-H system). Pure thermochemical properties and the assessed YSZ phase diagram were used in this analysis. Using the molar input of metals ((nY + nZr) and ( nY/(nY + nZr ) = 0.08)) as bases, equilibrium calculations showed that tetragonal YSZ formation was feasible. Tetragonal YSZ formation was feasible with high oxygen content (nO/(nY + nZr) > 8) and high temperature (T > 100°C) in the case of chloride CVD (Zr-Y-C-O-Cl-H-Inert). Tetragonal YSZ formation was feasible with high oxygen content (nO/( nY + nZr) > 5) and high temperature (T > 950°C) in the case of MOCVD (Zr-Y-C-O-H). Although solid carbon formation did not appear in chloride CVD, additional oxygen (nO/( nY + nZr) > 32) and low hydrogen content relative to carbon (nH/nC < 2) were required to avoid solid carbon formation in MOCVD. Coatings were deposited using a set of base conditions derived from the chemical equilibrium analysis. In chloride CVD, YCl3 was not included because of its low vapor pressure, thus, ZrCl4 was oxidized with the H2-CO2 gas mixture. Monoclinic ZrO2 coatings were deposited at the thermochemically optimized conditions (n O/(nY + nZr) > 8, T > 1004°C) with approximately 5.5 mum h-1 growth rate. In metal-organic CVD (MOCVD), liquid precursor solutions of Y- and Zr-beta-diketonate and Y- and Zr-n-butoxide precursors were used as the metal sources and O2 gas was used as the oxidation source. Using the Y- and Zr-beta-diketonate liquid precursor solution, tetragonal YSZ was deposited with a layered microstructure apparent and a maximum growth rate of approximately 14 mum h-1 (activation energy (E a) of 50.9 +/- 4.3 kJ mol-1). The growth rate (approximately 43 mum h-1 with Ea = 53.8 +/- 7.9 kJ mol-1) was improved using Y- and Zr- n-butoxide liquid precursor solutions, and the microstructure was columnar. Yet, two-phase deposition of monoclinic ZrO2 and tetragonal YSZ occurred. Results of electron-probe micro-analysis showed that the nY/(nY + nZr ) ratio was less than 45% of the nY/( nY + nZr) ratio in the liquid precursor solution.

Synthesis and Deprotonation of Aminophosphane Complexes: First K/N(H)R Phosphinidenoid Complexes and Access to a Complex with a P2 N-Ring Ligand.

PubMed

Majhi, Paresh Kumar; Kyri, Andreas Wolfgang; Schmer, Alexander; Schnakenburg, Gregor; Streubel, Rainer

2016-10-17

Synthesis of 1,1'-bifunctional aminophosphane complexes 3 a-e was achieved by the reaction of Li/Cl phosphinidenoid complex 2 with various primary amines (R=Me, iPr, tBu, Cy, Ph). Deprotonation of complex 3 a (R=Me) with potassium hexamethyldisilazide yielded a mixture of K/NHMe phosphinidenoid complex 4 a and potassium phosphanylamido complex 4 a'. Treatment of complex 3 c (R=tBu) and e (R=Ph) with KHMDS afforded the first examples of K/NHR phosphinidenoid complexes 4 c and e. The reaction of complex 3 c with 2 molar equivalents of KHMDS followed by PhPCl 2 afforded complexes 5 c,c', which possess a P 2 N-ring ligand. All complexes were characterized by NMR, IR, MS, and microanalysis, and additionally, complexes 3 b-e and 5 c' were scrutinized by single-crystal X-ray crystallography. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, characterisation and antibacterial activity of [(p-cym)RuX(L)](+/2+) (X = Cl, H2O; L = bpmo, bpms) complexes.

PubMed

Tripathy, Suman Kumar; Taviti, Ashoka Chary; Dehury, Niranjan; Sahoo, Anupam; Pal, Satyanaryan; Beuria, Tushar Kant; Patra, Srikanta

2015-03-21

Mononuclear half-sandwiched complexes [(p-cym)RuCl(bpmo)](ClO4) {[1](ClO4)} and [(p-cym)RuCl(bpms)](PF6) {[2](PF6)} have been prepared by reacting heteroscorpionate ligands bpmo = 2-methoxyphenyl-bis(3,5-dimethylpyrazol-1-yl)methane and bpms = 2-methylthiophenyl-bis(3,5-dimethylpyrazol-1-yl)methane, respectively, with a dimeric precursor complex [(p-cym)RuCl(μ-Cl)]2 (p-cym = 1-isopropyl-4-methylbenzene) in methanol. The corresponding aqua derivatives [(p-cym)Ru(H2O)(bpmo)](ClO4)2 {[3](ClO4)2} and [(p-cym)Ru(H2O)(bpms)](PF6)2 {[4](PF6)2} are obtained from {[1](ClO4)} and {[2](PF6)}, respectively, via Cl(-)/H2O exchange process in the presence of appropriate equivalents of AgClO4/AgNO3 + KPF6 in a methanol-water mixture. The molecular structures of the complexes {[1]Cl, [3](ClO4)2 and [4](PF6)(NO3)} are authenticated by their single crystal X-ray structures. The complexes show the expected piano-stool geometry with p-cym in the η(6) binding mode. The aqua complexes [3](ClO4)2 and [4](PF6)2 show significantly good antibacterial activity towards E. coli (gram negative) and B. subtilis (gram positive) strains, while chloro derivatives ({[1](ClO4)} and {[2](PF6)} are found to be virtually inactive. The order of antibacterial activity of the complexes according to their MIC values is [1](ClO4) (both 1000 μg mL(-1)) < [2](PF6) (580 μg mL(-1) and 750 μg mL(-1)) < [3](ClO4)2 (both 100 μg mL(-1)) < [4](PF6)2 (30 μg mL(-1) and 60 μg mL(-1)) for E. coli and B. subtilis strains, respectively. Further, the aqua complexes [3](ClO4)2 and [4](PF6)2 show clear zones of inhibition against kanamycin, ampicillin and chloramphenicol resistant E. coli strains. The detailed mechanistic aspects of the aforesaid active aqua complexes [3](ClO4)2 and [4](PF6)2 have been explored, and it reveals that both the complexes inhibit the number of nucleoids per cell in vivo and bind to DNA in vitro. The results indeed demonstrate that both [3](ClO4)2 and [4](PF6)2 facilitate the inhibition of bacterial growth by binding to DNA.

Instrumentation for Detecting Hazardous Materials.

DTIC Science & Technology

1980-06-01

CATALOG NUMBER 1940-4)_ _ _ _ _ _ 4. TITLE (,.d Subtitle) _ JVE OF r , AL*3O.[OYE_ D .- / Final ; , .. P - 4^NSTRUtENTAT ION FOR DETECTING HAZARDOUS...CL a D- 4- a ... E - 0US m -i M r i US U Ci 0 Ui . Ci C) Ci. 4.. 9* Ci0 44. 4-S i C U i 5U - . ’- -) 0 C- c -CiOZ E 0 04 CiC C’ - E-.0 m N 4- 10 m E4...1 z 0 - C)4 -4 54-1 C)) 04Q). 0U $4i 4I - 40. U a) 0)U r -H 0) -a 0r- u 1-- 1% 4J ( C.) 4 0 0 4~J >1) C) r ’ (0 4 T - -4 U) C C) 0 *- C)0 - 4 f 04 C) C

Cultural Resources Literature Search and Records Review - Upper Mississippi River Basin. Volume 7. Pool 6.

DTIC Science & Technology

1983-01-01

H 0- -1 . 0 - d U. 0- 4 X, i * ’w 7 E-4 rj U) r- c0 0 -4 P 4 H4 E-4 E 0- 4%D.10 0 -4 $4 )t% U4 ) H- to) 440 Ur- H- N -4-1 4--)4J 4 4-) U)iU $4 -.4 C...34I W,4. * 4-i W ) U z u L. U U En $-4 $4 -4 X M Z a)~ U4. ) 0 )c~ (a aUD ) La 0 -r - go)> 4l) Cl V U) M l W ’- V U) H-U) -4 35Cl ( P ’.44 0 $- Q ~- -H U...gr I E U C0 0C) t41-H. H- V U) 4.) En 0--4 10uVr LA I H- r- C3 U -4$k V C4J W :: - c Q)~ r. CN C3 r i-, 11 H - N n 04 004 4J E- 4 M 0 04 -4 UU) 94 0 p

3-(2,4-Dichloro­anilino)iso­benzo­furan-1(3H)-one1

PubMed Central

Odabaşoğlu, Mustafa; Büyükgüngör, Orhan

2008-01-01

In the mol­ecule of the title compound, C14H9Cl2NO2, the essentially planar phthalide group is oriented at a dihedral angle of 63.23 (5)° with respect to the substituted aromatic ring. In the crystal structure, inter­molecular C—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules, generating R 4 4(21) ring motifs to form a three-dimensional network. PMID:21202144

1-[1-(4-Chloro­phen­yl)ethyl­idene]carbono­hydrazide

PubMed Central

Du, Lingyun; Du, Lei; Wang, Shuhao

2009-01-01

The mol­ecular skeleton of the title mol­ecule, C9H11ClN4O, is essentially planar, the dihedral angle between the ring and the and N/N/C plane being 6.7 (3)°. In the crystal, inter­molecular N—H⋯O and N—H⋯N hydrogen bonds link the mol­ecules into ribbons propagated along [010]. PMID:21577542

Isolation and structures of sulfonium salts derived from thioethers: [{o-C(6)H(4)(CH(2)SMe)(2)}H][NbF(6)] and [{[9]aneS(3)}H][NbF(6)].

PubMed

Jura, Marek; Levason, William; Reid, Gillian; Webster, Michael

2009-10-07

Two very unusual sulfonium salts, [{o-C(6)H(4)(CH(2)SMe)(2)}H][NbF(6)] and [{[9]aneS(3)}H][NbF(6)], obtained from reaction of the thioethers with NbF(5) in CH(2)Cl(2) solution, are reported and their structures described; the eight-coordinate tetrafluoro Nb(v) cation of the dithioether is obtained from the same reaction.

Determination of product branching ratio of the ClO self-reaction at 298 K

NASA Astrophysics Data System (ADS)

Horowitz, A.; Bauer, D.; Crowley, J. N.; Moortgat, G. K.

1993-07-01

The Cl2-sensitized continuous photolysis of O3 mixtures in O2 was investigated at 298 K using time resolved single wavelength and diode array spectroscopy to monitor the decay of O3 and the formation of OClO. Φ-O3 was found to be 4.1±0.4. This value, combined with the determination of the initial rates of OClO formation, allowed the evaluation of the following branching ratios into the three bimolecular disproportionation channels of ClO reactions; k3a/k3 = 0.40 ± 0.08, k3b/k3 = 0.42 ± 0.08 and k3c/k3 = 0.18 ± 0.02 where ClO + ClO → Cl2 + O2 (3a), ClO + ClO → Cl + Cl + O2 (3b) and ClO + ClO → Cl + OClO (3c).

Crystal Structure and Energy Transfer in Double-Complex Salts Composed of Tris(2,2'-bipyridine)ruthenium(II) or Tris(2,2'-bipyridine)osmium(II) and Hexacyanochromate(III).

PubMed

Otsuka, Takuhiro; Takahashi, Naoto; Fujigasaki, Naoki; Sekine, Akiko; Ohashi, Yuji; Kaizu, Youkoh

1999-03-22

In crystals of double-complex salts [M(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O (M(2+) = Ru(2+), Os(2+); bpy = 2,2'-bipyridine), luminescence from (3)CT state of [M(bpy)(3)](2+) is partially quenched by [Cr(CN)(6)](3)(-) at 77 K and room temperature (RT). This quenching is attributed to intermolecular excitation energy transfer from the (3)CT state of [M(bpy)(3)](2+) to the (2)E(g) state of [Cr(CN)(6)](3)(-). Crystal structure and crystal parameters of [Os(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O: monoclinic, C2, a = 22.384(4) Å, b = 13.827(4) Å, c = 22.186(3) Å, beta = 90.70(2) degrees, V = 6866(2) Å(3), Z = 4, R = 0.0789, R(w) = 0.1932: are almost the same as those of [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O: monoclinic, C2, a = 22.414(2) Å, b = 13.7686(15) Å, c = 22.207(2) Å, beta = 90.713(8) degrees, V = 6852.9(12) Å(3), Z = 4, R = 0.0554, R(w) = 0.1679. Moreover, these double complex salts have the same distance and relative orientation between donor and acceptor. The rate of intermolecular energy transfer from [M(bpy)(3)](2+) to [Cr(CN)(6)](3)(-) was evaluated by the decay time of luminescence from (3)CT state of [M(bpy)(3)](2+) in single- and double-complex salts. The rate of energy transfer in [Os(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O (4.9 x 10(7) s(-)(1)) is about eight times larger than that in [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O (6.0 x 10(6) s(-)(1)) at 77 K. The difference of energy transfer rate is brought about by only the spectral overlap between the normalized luminescence spectrum from the (3)CT state of donor ([M(bpy)(3)](2+)) and the normalized excitation spectrum of the (2)E(g) state of acceptor ([Cr(CN)(6)](3)(-)) in the salts. Decay rates of the (3)CT state in [M(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O were measured as a function of temperature. A large enhancement of a decay rate from the (3)CT state was obtained for [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O as the temperature was increased. This result implies that an additional path from the (3)CT state of [Ru(bpy)(3)](2+) to the (2)T(2g) state of [Cr(CN)(6)](3)(-) would be opened for energy transfer with a rise in temperature in [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O.

The Synthesis of Calcium Salt from Brine Water by Partial Evaporation and Chemical Precipitation

NASA Astrophysics Data System (ADS)

Lalasari, L. H.; Widowati, M. K.; Natasha, N. C.; Sulistiyono, E.; Prasetyo, A. B.

2017-02-01

In this study would be investigated the effects of partial evaporation and chemical precipitation in the formation of calcium salt from brine water resources. The chemical reagents used in the study was oxalate acid (C2H2O4), ammonium carbonate (NH4)2CO3) and ammonium hydroxide (NH4OH) with reagent concentration of 2 N, respectively. The procedure was 10 liters brine water evaporated until 20% volume and continued with filtration process to separate brine water filtrate from residue (salt). Salt resulted from evaporation process was characterized by Scanning Electron Microscopy (SEM), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) techniques. Filtrate then was reacted with C2H2O4, (NH4)2CO3 and NH4OH reagents to get salt products in atmospheric condition and variation ratio volume brine water/chemicals (v/v) [10/1; 10/5; 10/10; 10/20; 10/30; 10:50; 20/1; 20/5; 20/10; 20/20; 20/30; 20:50]. The salt product than were filtered, dried, measured weights and finally characterized by SEM/EDS and XRD techniques. The result of experiment showed the chemical composition of brine water from Tirta Sanita, Bogor was 28.87% Na, 9.17% Mg, 2.94% Ca, 22.33% O, 0.71% Sr, 30.02% Cl, 1.51% Si, 1.23% K, 0.55% S, 1.31% Al. The chemical composition of salt resulted by partial evaporation was 53.02% Ca, 28.93%O, 9.50% Na, 2.10% Mg, 1.53% Sr, 1.20% Cl, 1.10% Si, 0.63% K, 0.40% S, 0.39% Al. The salt resulted by total evaporation was indicated namely as NaCl. Whereas salt resulted by partial evaporation was CaCO3 with a purity of 90 % from High Score Plus analysis. In the experiment by chemical precipitation was reported that the reagents of ammonium carbonate were more reactive for synthesizing calcium salt from brine water compared to reagents of oxalate acid and ammonium hydroxide. The salts precipitated by NH4OH, (NH4)2CO3, and H2C2O4 reagents were indicated as NaCl, CaCO3 and CaC2O4.H2O, respectively. The techniques of partial evaporation until 20% volume sample of brine water and chemical precipitation using (NH4)2CO3 reagent are recommended in the synthesis of calcium salts from brine water because are simple, flexible and economical.

High Coulombic efficiency aluminum-ion battery using an AlCl3-urea ionic liquid analog electrolyte.

PubMed

Angell, Michael; Pan, Chun-Jern; Rong, Youmin; Yuan, Chunze; Lin, Meng-Chang; Hwang, Bing-Joe; Dai, Hongjie

2017-01-31

In recent years, impressive advances in harvesting renewable energy have led to a pressing demand for the complimentary energy storage technology. Here, a high Coulombic efficiency (∼99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analog electrolyte made from a mixture of AlCl 3 and urea in a 1.3:1 molar ratio. The battery displays discharge voltage plateaus around 1.9 and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ∼73 mAh g -1 at a current density of 100 mA g -1 (∼1.4 C). High Coulombic efficiency over a range of charge-discharge rates and stability over ∼150-200 cycles was easily demonstrated. In situ Raman spectroscopy clearly showed chloroaluminate anion intercalation/deintercalation of graphite (positive electrode) during charge-discharge and suggested the formation of a stage 2 graphite intercalation compound when fully charged. Raman spectroscopy and NMR suggested the existence of AlCl 4 - , Al 2 Cl 7 - anions and [AlCl 2 ·(urea) n ] + cations in the AlCl 3 /urea electrolyte when an excess of AlCl 3 was present. Aluminum deposition therefore proceeded through two pathways, one involving Al 2 Cl 7 - anions and the other involving [AlCl 2 ·(urea) n ] + cations. This battery is a promising prospect for a future high-performance, low-cost energy storage device.

Rhenium(V)-oxo complexes of neutral and monoanionic tetraazamacrocycles. X-ray structures of trans-oxohydroxo(1,4,8,11-tetraazacyclotetradecane)rhenium(V) bis(perchlorate)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsang, B.W.; Reibenspies, J.; Martell, A.E.

1993-03-17

The complexes of ReO[sub 2][sup +] and ReO(OH)[sup 2+] with 1,4,8,11-tetraazacyclotetradecane (cyclam) and 1,4,8,11-tetraazacyclotetradecan-2-one (O[sub 1]cyclam) have been synthesized and characterized. The complexes were prepared by ligand exchange reactions of the macrocycles with a variety of starting compounds including ReOCl[sub 3](PPh[sub 3])[sub 2] and ReO[sub 2](en)[sub 2]Cl. The ReO(OH)[sup 2+] complexes have been structurally characterized. ReO(OH)(H[sub [minus]1]O[sub 1]cyclam)ReO[sub 4] crystallizes in the monoclinic P2[sub 1]/n space group with a = 10.308(3) [Angstrom], b = 9.527(2) [Angstrom], c = 17.808(3) [Angstrom], and [beta] = 106.57(2)[degrees]. ReO(OH)(cyclam)(ClO[sub 4])[sub 2] crystallizes in the monoclinic C2/c space group with a = 9.734(4) [Angstrom], bmore » = 16.999(5) [Angstrom], c = 12.187(5) [Angstrom], and [beta] = 106.36[degrees]. The complex ReO(OH)(H[sub [minus]1]O[sub 1]cyclam)ReO[sub 4] has a distorted octahedral structure with one short ReO(oxo) bond and one long ReO(hydroxo) bond (1.685(8) vs 1.970(8) [Angstrom]). The deprotonated amide ReN(sp[sup 2]) bond is shorter than the other three ReN(sp[sup 3]) bond lengths (1.98(1) vs 2.13(3) [Angstrom] (average)). The structure of the ReO(OH)(cyclam)(ClO[sub 4])[sub 2] complex shows no distinction between the lengths of the two ReO(oxo and hydroxo) bonds (1.766(5) [Angstrom]) due to disorder of the oxo and hydroxo groups. Spectroscopic evidence is reported to confirm the presence of both oxo and hydroxo groups coordinated to rhenium. 38 refs., 7 figs., 6 tabs.« less

Inhalation Toxicity of Single Materials and Mixtures. Phase 2.

DTIC Science & Technology

1991-03-29

vitro xenobiotic metabolism studies), and "optional" endpoints that could...82170 *t -1 - 1.- * ~0 0 2, W 4 0 ’ D 0 ’ 0. :9 C> 0 0D 0 0n 0 0CL L ~~’* 0 ( ’N ’N ’N ’N ’ ’ NjN ’ U ww 0 0 C. .0 0 0 LA 0 ull GO 0o o N. W 31k 00 0 0 L...I4 0f 0D 04 0 L L 0 0 c) LA LA 0j 02 N. 4 4 ’o 0 0a 0 0 LA t-L L AA L 02 >2 > 2 >- W- . c >17 (A ’N D ’N ’N ’N ’N ’N ’N ’N 0 - ~ .0 0 0 0 - 0 𔃺 N LA

Kinetic studies on the reaction of cob(II)alamin with hypochlorous acid: Evidence for one electron oxidation of the metal center and corrin ring destruction.

PubMed

Dassanayake, Rohan S; Farhath, Mohamed M; Shelley, Jacob T; Basu, Soumitra; Brasch, Nicola E

2016-10-01

Kinetic and mechanistic studies on the reaction of a major intracellular vitamin B 12 form, cob(II)alamin (Cbl(II)), with hypochlorous acid/hypochlorite (HOCl/OCl - ) have been carried out. Cbl(II) (Co(II)) is rapidly oxidized by HOCl to predominately aquacobalamin/hydroxycobalamin (Cbl(III), Co(III)) with a second-order rate constant of 2.4×10 7 M -1 s -1 (25.0°C). The stoichiometry of the reaction is 1:1. UHPLC/HRMS analysis of the product mixture of the reaction of Cbl(II) with 0.9mol equiv. HOCl provides support for HOCl being initially reduced to Cl and subsequent H atom abstraction from the corrin macrocycle occurring, resulting in small amounts of corrinoid species with two or four H atoms fewer than the parent cobalamin. Upon the addition of excess (H)OCl further slower reactions are observed. Finally, SDS-PAGE experiments show that HOCl-induced damage to bovine serum albumin does not occur in the presence of Cbl(II), providing support for Cbl(II) being an efficient HOCl trapping agent. Copyright © 2016 Elsevier Inc. All rights reserved.

Subthreshold parallel pumping experiments on the quasi one-dimensional S = {1}/{2} ferromagnets [C 6H 11NH 3]CuBr 3 and [C 6H 11NH 3]CuCl 3

NASA Astrophysics Data System (ADS)

Hoogerbeets, R.; Wiegers, S. A. J.; Van Duyneveldt, A. J.

1985-04-01

Subthreshold parallel pumping experiments on [C 6H 11NH 3]CuBr 3 (abbreviated as CHAB) and [C 6H 11NH 3]CuCl 3 (CHAC) at 9.6 and 18.3 GHz are reported. It is shown that the experimental results can be explained using the values of the parameters as have been obtained from previously reported FMR measurements.

Crystal structure of trans-di­fluoridotetra­kis(pyridine-κN)chromium(III) tri­chlorido­(pyridine-κN)zincate monohydrate from synchrotron data

PubMed Central

Moon, Dohyun; Choi, Jong-Ha

2014-01-01

In the asymmetric unit of the title compound, [CrF2(C5H5N)4][ZnCl3(C5H5N)]·H2O, there are two independent complex cations, one tri­chlorido­(pyridine-κN)zincate anion and one solvent water mol­ecule. The cations lie on inversion centers. The CrIII ions are coordinated by four pyridine (py) N atoms in the equatorial plane and two F atoms in a trans axial arrangement, displaying a slightly distorted octa­hedral geometry. The Cr—N(py) bond lengths are in the range 2.0873 (14) to 2.0926 (17) Å while the Cr—F bond lengths are 1.8609 (10) and 1.8645 (10) Å. The [ZnCl3(C5H5N)]− anion has a distorted tetra­hedral geometry. The Cl atoms of the anion were refined as disordered over two sets of sites in a 0.631 (9):0.369 (9) ratio. In the crystal, two anions and two water mol­ecules are linked via O—H⋯Cl hydrogen bonds, forming centrosymmetric aggregates. In addition, weak C—H⋯Cl, C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.712 (2) and 3.780 (2)Å] link the components of the structure into a three-dimensional network. PMID:25484725

Department of the Navy Justification of Estimates Amended Fiscal Year 1988 and 1989 Biennial Budget Submitted to Congress February 1988. Operation and Maintenance, Navy. Book 3. Budget Activity 8: Training Medical and OPGA Budget Activity 9: Administration and Assoc Acts. Budget Activity 10: Support to Other Nations Budget Activity 11: Special Operations Forces

DTIC Science & Technology

1988-02-01

8217dCL D~0U :2aw u> Q >0.’a 41 ’ 0 :1:5 - r.4 J0)C.Ř£ to 4 td " C CO to) U) 0 " A. O cw 0 > ;3 w 4 144 w. V).M t 00 J - 4bD £ (d Ŕ 3.0 bcL W 0 .𔃾 0) 03 J...to -4 0 4) 44 41 P-4 Ma to 04 to W 0) M V) W 41 :b% Cý .,q r. ed -m 0 td rd .- a to w to w w to "-4 as 44 r-.4 w 1-4 W w (v to ow ýj M to) C: to CL (1...P -4P0-4 oo W v w ~’L0 . V)4) >%r.0 4w D bo 1-ý40 U G) 0 w w H 0ww 0 w0..4.J. 9 . 40. 𔃺 -1 4 0 WL O.1-w ý400.0 A. ’c-c 0I v’- U w 1 -4U0w ( td (0 L

Syntheses, structures and properties of homo- and heterobimetallic complexes of the type [Zn(tren)NCS] 2[M(NCS) 4] [tren = tris(2-aminoethyl)amine; M = Zn, Cu

NASA Astrophysics Data System (ADS)

Chattopadhyay, Soumi; Bhar, Kishalay; Das, Sumitra; Chantrapromma, Suchada; Fun, Hoong-Kun; Ghosh, Barindra Kumar

2010-04-01

A 2:2:1:6 molar ratio of Zn(ClO 4) 2·6H 2O, tris(2-aminoethyl)amine (tren), Zn(ClO 4) 2·6H 2O/Cu(ClO 4) 2·6H 2O and NH 4NCS in methanol-water solution mixtures affords homo-/heterobimetallic compounds of the type [Zn(tren)NCS] 2[M(NCS) 4] (M = Zn, 1; M = Cu, 2) which have been characterized using microanalytical, spectroscopic, magnetic and other physicochemical results. The structures of the compounds are determined by X-ray diffraction measurements. Structural analyses reveal that 1 and 2 are isomorphous and consist of two discrete [Zn(tren)NCS] + cations and a [M(NCS) 4] 2- (M = Zn/Cu) anion. Zinc(II) centers in the [Zn(tren)NCS] + units adopt distorted trigonal bipyramidal geometry with ZnN 5 chromophores coordinated through four N atoms of tren and one N atom of terminal thiocyanate. Each metal(II) center in [M(NCS) 4] 2- has a distorted tetrahedral coordination environment with an MN 4 chromophore ligated by four N atoms of the terminal thiocyanates. In solid state, doubly N-H…S hydrogen bonded 1D chains of [Zn(tren)NCS] + cations are interconnected by tetrahedral [Zn(NCS) 4] 2-/[Cu(NCS) 4] 2- anions through cooperative N-H…S and N-H…N (in 1) and N-H…S and C-H…S (in 2) hydrogen bonds resulting in 3D network structures. Establishment of such networks seems to be aiding the crystallization.

Limits on the Higgs boson lifetime and width from its decay to four charged leptons

DOE PAGES

Khachatryan, Vardan

2015-10-22

Constraints on the lifetime and width of the Higgs boson are obtained from H → ZZ → 4ℓ events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 fb -1 at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of τ H < 1.9 × 10 -13 s at the 95% confidence level (C.L.), corresponding to a lower bound on the width of Γ H > 3.5more » × 10 -9 MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From our measurement, a joint constraint is set on the Higgs boson width and a parameter f ΛQ that expresses an anomalous coupling contribution as an on-shell cross-section fraction. Additionally, the limit on the Higgs boson width is Γ H<46 MeV with f ΛQ unconstrained and Γ H < 26 MeV for f ΛQ = 0 at the 95% C.L. The constraint f ΛQ < 3.8 × 10 -3 at the 95% C.L. is obtained for the expected standard model Higgs boson width.« less

Pathway Study of Cl-cycle on Mars, Step-I & II: Oxychlorine Salts and Electrostatic Discharge Phenomenon in a Mars Chamber

NASA Astrophysics Data System (ADS)

Wu, Z.; Wang, A.; Ling, Z.; Li, B.; Zhang, J.; Xu, W.

2015-12-01

The directly measured high ClO4-/Cl- ratio (4.3-8.75) at Phoenix site and the implied ClO4- existences at Curiosity and Viking sites reminded Mars science community on the importance of (1) the global distribution of ClO4-/Cl- ratio; (2) the mechanisms that are responsible for Cl- to ClOy- (y=1,2,3,4) transformation; and (3) the current and historical Cl- cycle on Mars. Our goal is to study electrostatic discharge (ESD) in a Mars Chamber, as one of the four proposed mechanisms for the formation of Martian perchlorate. ESD was anticipated during dust storm/devil on Mars. A model estimated that ESD generated oxidants can be 200 times of those produced by photochemistry. Our study is conducted in three steps. Firstly, oxychlorine salts, NaClOy, Mg(ClO4)2.xH2O (x=0,6), and Ca(ClO4)2.xH2O (x=0,4), were analyzed at ambient conditions using MIR, NIR (1.4-2.6 µm), Raman spectroscopy, and in a Mars Chamber using in-situ NIR and Raman spectroscopy. Our purpose is to understand their phase transition and spectral change at Mars pressure (P) and temperature (T) conditions. We have found: (1) Under current surface/subsurface P-T conditions in mid-latitudes/equatorial regions on Mars, Mg(ClO4)2.6H2O and Ca(ClO4)2.4H2O are stable, while the hydration degree of NaClO4.H2O would increase at T<-30℃ and decrease in 5

The use of functionalized zirconocenes as precursors to silica-supported zirconocene olefin polymerization catalysts

NASA Astrophysics Data System (ADS)

Cheng, Xu

2001-07-01

Me3Si substituents adjacent to Cp2MCl2 (M = Ti, Zr, Hf) are converted to BrMe2Si groups using BBr 3. The high reactivity of the Si-Br bonds toward nucleophiles such as water suggested that these substituents could react with hydroxylated silica surfaces, immobilizing the metallocenes. This dissertation concerns the syntheses of electrophile-functionalized zirconocene dihalide complexes and their use as precursors to silica-supported metallocene olefin polymerization catalysts. First we extended the metallocene "functionalization" chemistry to obtain substituents bearing more than one electrophilic bond. (Me3Sn) 2C5H4 combined with CpZrCl3 in toluene to afford (eta5-Me3Sn-C5H4)CpZrCl 2 (A). Reactions of A with electrophiles (E-X = Cl2B-Cl, I-Cl, and I-I) afforded (eta5-XMe 2Sn-C5H4)CpZrCl2 (and E-Me) cleanly. The reaction of A with BBr3 afforded either (eta5-BrMe2Sn-C5H4)CpZrBr2 (25 °C, 10 min) or (eta5-Br2MeSn-C5H 4)CpZrBr2 (25 °C, 15 h). Ph2MeSi-C5H 4Li combined with ZrCl4•2THF to afford (eta 5-Ph2MeSi-C5H4)2ZrCl 2 (B). The reaction of B with BCl3 led to incomplete cleavage of the Ph-Si bonds, however treatment of B with BBr3 afforded (eta5-Br2MeSi-C 5H4)2ZrBr2 (C) efficiently. X-ray crystal structures of (eta5-ClMe2Sn-C 5H4)CpZrCl2•1/2toluene, (eta 5-Br2MeSn-C5H4)CpZrBr2•THF, B, and C were obtained. Metallocene C reacts with water to afford an oligosiloxane-supported zirconocene dibromide. Spectroscopic characterization suggested a stereoregular structure in which the metallocene units have meso symmetry. The oligomeric substance showed high activity for homogeneous ethylene polymerization. Supported metallocene olefin polymerization catalysts were prepared by combining a functionalized metallocene precursor (Cp2ZrBr 2 bearing either BrMe2Si or Br2MeSi groups) and partially dehydroxylated silica. The activities of the immobilized zirconocene catalysts decreased and the stabilities increased with increasing number of tethers. The immobilized catalyst prepared from (eta5-Br 2MeSi-C5H4)2ZrBr2, which is assumed to form two "double-tethers" to silica, was significantly more active than the catalyst prepared from [eta5-1,3-(BrMe 2Si)2C5H3]2ZrBr2, which is assumed to form four "single-tethers" to silica. Catalyst leaching was observed in all the immobilized zirconocene catalysts. Finally we report model studies on the stability of the Si-O-Si bonds toward methylaluminoxane (MAO). The reaction of (eta5-BrMe 2Si-C5H4)CpZrBr2 with tBuMe 2SiOH results in the formation of Si-O-Si bonds; addition of NEt 3 results in further reaction to afford Si-O-Zr bonds. The reaction of Me3Si-O-SiMe3 with MAO showed that Si-O-Si bonds can be cleaved under the conditions of our polymerization reactions.

Selective cyclopalladation of R3P=NCH2Aryl iminophosphoranes. Experimental and computational study.

PubMed

Bielsa, Raquel; Navarro, Rafael; Urriolabeitia, Esteban P; Lledós, Agustí

2007-11-26

The orientation of the orthopalladation of iminophosphoranes R3P=NCH2Aryl (R=Ph, Aryl=Ph (1a), C6H(4)-2-Br (1b), C6H4-Me-2 (1e), C6H3-(Me)(2)-2,5 (1f); R=p-tolyl, Aryl=Ph (1c); R=m-tolyl, Aryl=Ph (1d); R3P=MePh2P, and Aryl=Ph (1g)) has been studied. 1a reacts with Pd(OAc)2 (OAc=acetate) giving endo-[Pd(micro-Cl){C,N-C6H4(PPh2=NCH2Ph)-2}]2 (3a), while exo-[Pd(micro-Br){C,N-C6H4(CH2N=PPh3)-2}]2 (3b) could only be obtained by the oxidative addition of 1b to Pd2(dba)3. The endo form of the metalated ligand is favored kinetically and thermodynamically, as shown by the conversion of exo-[Pd(micro-OAc){C,N-C6H4(CH2N=PPh3)-2}]2 (2b) into endo-[Pd(micro-OAc){C,N-C6H4(PPh2=NCH2Ph)-2}]2 (2a) in refluxing toluene. The orientation of the reaction is not affected by the introduction of electron-releasing substituents at the Ph rings of the PR3 (1c and 1d) or the benzyl units (1e and 1f), and endo complexes (3c-3f) were obtained in all cases. The palladation of MePh2P=NCH2Ph (1g) can be regioselectively oriented as a function of the solvent. The exo isomer [Pd(micro-Cl){C6H4(CH2N=PPh2Me)-2}]2 (exo-3g) is obtained in refluxing CH2Cl2, while endo-[Pd(micro-Cl){C,N-C6H4(PPh(Me)=NCH2Ph)-2}]2 (endo-3g) can be isolated as a single isomer in refluxing toluene. In this case, the exo metalation is kinetically favored while an endo process occurs under thermodynamic control, as shown through the rearrangement of [Pd(micro-OAc){C6H4(CH2N=PPh2Me)-2}]2 (exo-2g) into [Pd(micro-OAc){C,N-C6H4(P(Ph)Me=NCH2Ph)-2}]2 (endo-2g) in refluxing toluene. The preference for the endo palladation of 1a and the kinetic versus thermodynamic control in 1g has been explained through DFT studies of the reaction mechanism.

Aerobic biodegradation of amines in industrial saline wastewaters.

PubMed

Campo, Pablo; Platten, William; Suidan, Makram T; Chai, Yunzhou; Davis, John W

2011-11-01

The treatment of hypersaline wastewaters represents a challenge since high salt concentrations disrupt bacteria present in normal biological treatments. This study was conducted to determine the fate of amines in two hypersaline wastewaters obtained from an industrial treatment plant processing influents with 3% and 7% of NaCl. The compounds were aniline (ANL), 4,4'-methylenedianiline (4,4'-MDA), cyclohexylamine (CHA), N-(2-aminoethyl)ethanolamine (AEA), N,N-diethylethanolamine (DEA), N,N-bis(2-hydroxyethyl)methylamine (MDEA), and tris(2-hydroxyethyl)amine (TEA). Mixtures of these chemicals with a mixed liquor suspended solids concentration of 1000 mg L(-1) were prepared at two salinities (3% and 7% NaCl). Ethanolamines were readily biodegraded at both salinities, following first-order kinetics with half-lives ranging between 10 and 58 h. Hydroxyl groups present in the ethanolamines had a positive impact on the biodegradation. Salinity did not affect the biodegradation rate of TEA and MDEA, whereas AEA and DEA degraded faster in 3% NaCl. After 48h, CHA was metabolized within a 24-h period in 3% NaCl, while no degradation was observed in 7% NaCl. ANL exhibited lag phases in both salinities and, in the following 24-h period, ANL concentrations dropped 40% and disappeared after 48 h. 4,4'-MDA degraded in 3% NaCl (half-life of 123 h) and remained unaltered after 120 h in 7% NaCl. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mercury-Bridged Cobaltacarborane Complexes Containing B-Hg-B Three-Center Bonds. Synthesis and Structure of mu, mu’-((n5-C5R5)Co(CH3)2C2B3H4)Hg, mu-(n(5)-C5R5)Co(CH3)2C2B3H4)HgCl, (R=H, CH3) and Related Compounds.

DTIC Science & Technology

1980-11-01

MERCURY-BRIDGED COBALTACARBORANE COMPLEXES CONTAINING B-HG-B TH--ETC(U) NOV 80 D C FINSTER . R N GRIMES N0 0 0 1 4-75-0305 UNCLASSXFIED TR󈧨 NL ILn...C5R5) Co 3)2C2B3 4 2 5 .- -C5R5 )Co(CH3)2C2B3H4 ]HgCl, (R=H, CH3 ) and Related Compounds, David C./ Finster -- Russell N./Grimes ( Department of Chemistry...Compounds 1 \\David C. Finster And Russell N. Grimes* Abstract. Reactions of the nid~p-cobaltacarborane anions 01CR )(C 3 )C BH and [n (H 1oC ihH~5n 5

Optimisation of the reaction conditions for the production of cross-linked starch with high resistant starch content.

PubMed

Kahraman, Kevser; Koksel, Hamit; Ng, Perry K W

2015-05-01

The optimum reaction conditions (temperature and pH) for the preparation of cross-linked (CL) corn and wheat starches with maximum resistant starch (RS) content were investigated by using response surface methodology (RSM). According to the preliminary results, five levels were selected for reaction temperature (38-70 °C) and pH (10-12) in the main study. RS contents of the CL corn and wheat starch samples increased with increasing temperature and pH, and pH had a greater influence on RS content than had temperature. The maximum RS content (with a maximum p value of 0.4%) was obtained in wheat starch cross-linked at 38 °C and pH 12. In the case of CL corn starch, the optimum condition was 70 °C and pH 12. CL corn and wheat starch samples were also produced separately under the optimum conditions and their RS contents were 80.4% and 83.9%, respectively. These results were also in agreement with the values predicted by RSM. Copyright © 2014 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Yu-Fang; Kong, Lin-Jun; Lee, Yuan-Pern

Irradiation at 239 {+-} 20 nm of a p-H{sub 2} matrix containing methoxysulfinyl chloride, CH{sub 3}OS(O)Cl, at 3.2 K with filtered light from a medium-pressure mercury lamp produced infrared (IR) absorption lines at 3028.4 (attributable to {nu}{sub 1}, CH{sub 2} antisymmetric stretching), 2999.5 ({nu}{sub 2}, CH{sub 3} antisymmetric stretching), 2950.4 ({nu}{sub 3}, CH{sub 3} symmetric stretching), 1465.2 ({nu}{sub 4}, CH{sub 2} scissoring), 1452.0 ({nu}{sub 5}, CH{sub 3} deformation), 1417.8 ({nu}{sub 6}, CH{sub 3} umbrella), 1165.2 ({nu}{sub 7}, CH{sub 3} wagging), 1152.1 ({nu}{sub 8}, S=O stretching mixed with CH{sub 3} rocking), 1147.8 ({nu}{sub 9}, S=O stretching mixed with CH{sub 3} wagging),more » 989.7 ({nu}{sub 10}, C-O stretching), and 714.5 cm{sup -1} ({nu}{sub 11}, S-O stretching) modes of syn-CH{sub 3}OSO. When CD{sub 3}OS(O)Cl in a p-H{sub 2} matrix was used, lines at 2275.9 ({nu}{sub 1}), 2251.9 ({nu}{sub 2}), 2083.3 ({nu}{sub 3}), 1070.3 ({nu}{sub 4}), 1056.0 ({nu}{sub 5}), 1085.5 ({nu}{sub 6}), 1159.7 ({nu}{sub 7}), 920.1 ({nu}{sub 8}), 889.0 ({nu}{sub 9}), 976.9 ({nu}{sub 10}), and 688.9 ({nu}{sub 11}) cm{sup -1} appeared and are assigned to syn-CD{sub 3}OSO; the mode numbers correspond to those used for syn-CH{sub 3}OSO. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers, infrared intensities, and deuterium isotopic shifts with those predicted with the B3P86/aug-cc-pVTZ method. Our results extend the previously reported four transient IR absorption bands of gaseous syn-CH{sub 3}OSO near 2991, 2956, 1152, and 994 cm{sup -1} to 11 lines, including those associated with C-O, O-S, and S=O stretching modes. Vibrational wavenumbers of syn-CD{sub 3}OSO are new. These results demonstrate the advantage of a diminished cage effect of solid p-H{sub 2} such that the Cl atom, produced via UV photodissociation of CH{sub 3}OS(O)Cl in situ, might escape from the original cage to yield isolated CH{sub 3}OSO radicals.« less

ZnCl 2- and NH 4Cl-hydroponics gel electrolytes for zinc-carbon batteries

NASA Astrophysics Data System (ADS)

Khalid, N. H.; Ismail, Y. M. Baba; Mohamad, A. A.

Absorbency testing is used to determine the percentage of ZnCl 2 or NH 4Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl 2 or NH 4Cl solution decreases with increasing solution concentration. The conductivity of ZnCl 2- and NH 4Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm -1 at 3 M ZnCl 2 and 7 M NH 4Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 Ω, a maximum power density of 12.7 and 12.2 mW cm -2, and a short-circuit current density of 29.1 and 33.9 mA cm -2 for ZnCl 2- and NH 4Cl-HPG electrolytes, respectively.

Calculation and synthesis of ZrC by CVD from ZrCl4-C3H6-H2-Ar system with high H2 percentage

NASA Astrophysics Data System (ADS)

Zhu, Yan; Cheng, Laifei; Ma, Baisheng; Gao, Shuang; Feng, Wei; Liu, Yongsheng; Zhang, Litong

2015-03-01

A thermodynamic calculation about the synthesis of ZrC from the ZrCl4-C3H6-H2-Ar system with high percentage of H2 was performed using the FactSage thermochemical software. According to the calculation, ZrC coating was synthesized on graphite substrates and carbon fibers by a low pressure chemical vapor deposition (LPCVD) process, and growth rate of the ZrC coating as a function of temperature was investigated. The surface diagrams of condensed-phases in this system were expressed as the functions of the deposition temperature, total pressure and reactant ratios of ZrCl4/(ZrCl4 + C3H6), H2/(ZrCl4 + C3H6), and the yield of the products was determined by the diagrams. A smooth and dense ZrC coating could be synthesized under the instruction of the calculated parameters. The morphologies of the ZrC coatings were significantly affected by temperature and gases flux. The deposition temperature is much lower than that from the ZrCl4-CH4-H2-Ar system.

Structures and properties of spherical 90-vertex fullerene-like nanoballs.

PubMed

Scheer, Manfred; Schindler, Andrea; Bai, Junfeng; Johnson, Brian P; Merkle, Roger; Winter, Rainer; Virovets, Alexander V; Peresypkina, Eugenia V; Blatov, Vladislav A; Sierka, Marek; Eckert, Hellmut

2010-02-15

By applying the proper stoichiometry of 1:2 to [Cp(R)Fe(eta(5)-P(5))] and CuX (X=Cl, Br) and dilution conditions in mixtures of CH(3)CN and solvents like CH(2)Cl(2), 1,2-Cl(2)C(6)H(4), toluene, and THF, nine spherical giant molecules having the simplified general formula [Cp(R)Fe(eta(5)-P(5))]@[{Cp(R)Fe(eta(5)-P(5))}(12){CuX}(25)(CH(3)CN)(10)] (Cp(R)=eta(5)-C(5)Me(5) (Cp*); eta(5)-C(5)Me(4)Et (Cp(Et)); X=Cl, Br) have been synthesized and structurally characterized. The products consist of 90-vertex frameworks consisting of non-carbon atoms and forming fullerene-like structural motifs. Besides the mostly neutral products, some charged derivatives have been isolated. These spherical giant molecules show an outer diameter of 2.24 (X=Cl) to 2.26 nm (X=Br) and have inner cavities of 1.28 (X=Cl) and 1.20 nm (X=Br) in size. In most instances the inner voids of these nanoballs encapsulate one molecule of [Cp*Fe(eta(5)-P(5))], which reveals preferred orientations of pi-pi stacking between the cyclo-P(5) rings of the guest and those of the host molecules. Moreover, pi-pi and sigma-pi interactions are also found in the packing motifs of the balls in the crystal lattice. Electrochemical investigations of these soluble molecules reveal one irreversible multi-electron oxidation at E(p)=0.615 V and two reduction steps (-1.10 and -2.0 V), the first of which corresponds to about 12 electrons. Density functional calculations reveal that during oxidation and reduction the electrons are withdrawn or added to the surface of the spherical nanomolecules, and no Cu(2+) species are involved.

GTE_TRACEP_DC8 Parameters 4

Atmospheric Science Data Center

2013-02-18

... Methyl bromide (CH3Br) Bromopropane (C3H7Br) Methyl Chloride(CH3Cl) Ethyl Chloride (C2H5Cl) Vinyl chloride (C2H3Cl) ... Trichloroethylene (C2HCl3) Tetrachloroethylene (C2Cl4) Methylene bromide (CH2Br2) Chlorodibromomethane(CHClBr2) Bromoform ...

Effect of some metal chlorides on the transformation of pyrite to pyrrhotite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiley, R.H.; Konopka, K.L.; Hinckley, C.C.

1982-08-01

Samples of the iron-sulfide mineral pyrrhotite were prepared using a procedure designed to closely model the pyrite-to-pyrrhotite conversion that occurs during coal-conversion processing. Pyrite mixed with graphite converts to mixtures of monoclinic and hexagonal pyrrhotite when heated at 500C for 4.5 hours, and an iron-rich pyrrhotite (Fe10S11) forms at 600 to 700C. In addition to temperature effects, the pyrrhotites formed from pyrite in graphite are also dependent on additives or impurities in the form of metal salts. The pyrrhotites used in this study were prepared in the presence of selected transition metal chlorides: PdCl2, NiCl2, CoCl2, ZnCl2, MoCl5, and ZrCl4.more » When these metal salts were used, pyrrhotites with an increased number of iron vacancies were produced. For example, in the presence of ZrCl4 at temperatures as high as 700C, a pyrrhotite was produced that exhibited Moessbauer magnetic-splitting values characteristic of pyrrhotite with a high number of iron vacancies (iron-poor). These pyrrhotites were then converted to troilite at 400C in the presence of CO and H2; and this troilite is an active catalyst for the Fischer-Tropsch synthesis, alkene hydrogenation, the Boudouard reaction, the water-gas shift reaction, and the hydrodesulfurization of organic sulfur compounds.« less

Effects of soy sauce on physicochemical and textural properties of tumbled chicken breast.

PubMed

Kim, H W; Hwang, K E; Song, D H; Kim, Y J; Lim, Y B; Choi, J H; Choi, Y S; Kim, H Y; Kim, C J

2014-03-01

The objective of this study was to evaluate the effects of soy sauce on the physicochemical and textural properties of tumbled chicken breasts. Chicken breasts marinated with distilled water (Con), 4% NaCl solution, 4% NaCl and lactic acid solution (pH 4.9), and soy sauce solution (4% salt concentration and pH 4.9) were vacuum tumbled at 3°C for 60 min. The chicken breast marinated with soy sauce solution showed lower lightness and higher redness and yellowness due to the color of the soy sauce. The acidic marinades led to a decrease in pH value of tumbled chicken breast. The acidic marinades increased collagen solubility of sample compared with 4% NaCl solution, resulting in decreased shear force. Water-holding capacity, marination and cooking yields, and solubility of myofibrillar proteins were mainly affected by the presence of salt in the marinade, rather than by pH alternation. Our results suggested that soy sauce marination can improve the tenderness of tumbled chicken breast.

Photochemical formation rates of organic aerosols through time-resolved in situ laboratory measurements

NASA Astrophysics Data System (ADS)

Ádámkovics, Máté; Boering, Kristie A.

2003-08-01

The fundamental kinetics of photochemical particle formation and the mechanism(s) for polymerization of hydrocarbons to form condensable species under anoxic conditions have yet to be determined experimentally. Thus these processes remain highly parameterized in models of planetary atmospheres. We have developed instrumentation for simultaneously measuring the net production rates of complex gas-phase hydrocarbons and of organic aerosols formed from irradiating mixtures of simple precursor gases through online quadrupole mass spectrometry measurements of stable gas-phase species and in situ optical scattering detection of the particulates at 633 nm. The new technique and results for the generation of hydrocarbon aerosol from the irradiation of pure, gas-phase CH4 at a pressure of 70 Torr with 8.8 +/- 0.8 × 1015 photons s-1 of vacuum ultraviolet light (120-300nm) are reported. The net production rates for the following gaseous species are measured: H2 = 9.9 +/- 2.2 . 1011, C2H2 = 2.8 +/- 0.5 . 1010, C2H4 = 5.5 +/- 9.4 . 109, C2H6 = 8.6 +/- 2.5 . 1010, C3H4 = 2.5 +/- 1.2 . 109, C4H2 = 6.6 +/- 5.0 . 108, C4H10 = 1.3 +/- 0.5 . 1010 cm-3 s-1. The production of hydrocarbon particulates is detected by optical scattering, and the condensed phase C-C bond formation rate is inferred to be 7.5 +/- 3.1 . 1011 cm-3 s-1. Applications of this technique to the atmospheres of Titan and terrestrial-like planets, such as the early Earth before the rise of molecular oxygen, are discussed.

Structure characterization, photoluminescence and dielectric properties of a new hybrid compound containing chlorate anions of zincate (II)

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Ben Soltan, Wissem; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-04-01

A new hybrid compound, bis (2-aminophenylenamonium) tetrachlorozincate (II), was synthesized and formulated as (C6H9N2)2ZnCl4. Its crystal structure was solved by single crystal X-ray diffraction reveling that compound crystallizes in the monoclinic system, space group C2/c (N°: 15) with cell parameters a = 7.4957(4) Å, b = 25.6837(15) Å, c = 9.4041(5) Å, β = 94.35(0)°, V = 1805.23(45) Å3. Their atomic arrangement can be described as an alternation of inorganic and organic layers, [ZnCl4]2- tetrahedral anions and 2-aminophenylenamonium cations. The cohesion of the atomic arrangement is ensured by hydrogen bonds (strong Nsbnd H⋯N and weak Nsbnd H⋯Cl) and π-π stacking interactions between identical antiparallel organic moieties. In optical transmission and photoluminescence measurements, this material exhibit two absorption bands (253 and 316 nm) and a strong emission line (390 nm), while the thermal analysis disclosed a phase transition at 420-445 K previously to the sample decomposition at 476 K. Finally, electrical measurements were performed to discuss the phase-transition mechanism.

XAFS Study of Molten ZrCl4 in LiCl-KCl Eutectic

NASA Astrophysics Data System (ADS)

Okamoto, Yoshihiro; Motohashi, Haruhiko

2002-05-01

The local structure of motlen ZrCl4 in LiCl-KCl eutectic was investigated by using an X-ray absorption fine structure (XAFS) of the Zr K-absorption edge. The nearest Zr4+-Cl- distance and coordination number from the curve fitting analysis were (2.51±0.02) Å and 5.9±0.6, respectively. These suggest that a 6-fold coordination (ZrCl6)2- is predominant in the molten mixture.

Structure determination of two structural analogs, named 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16F2N4S) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16ClFN4S) by synchrotron X-ray powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

Two novel compounds, 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16F 2N 4S) (1) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16ClFN 4S) (2), have been designed and synthesized as cytotoxic agents. The compounds were characterized by infrared, proton nuclear magnetic resonance, mass spectral data, elemental analysis and X-ray powder diffraction. The present study comprises spectral data and crystal structures of these novel compounds determined from synchrotron X-ray powder diffraction data. The structure solutions were obtained by simulated annealing. The final structures were achieved by Rietveld refinement using soft restraints for all bond lengths, bond angles, and planar groups. Both compounds crystallize in space groupmore » $$P\\bar 1$$,Z= 2, with the unit-cell parametersa= 6.37433(9),b= 11.3641(2),c= 14.09115(19) Å,α= 80.1740(8)°,β= 85.1164(8)°,γ= 80.9831(10)°,V= 991.55(3) Å 3of compound (1) anda= 6.53736(6),b= 11.55725(15),c= 14.01373(13) Å,α= 80.3323(7)°,β= 84.8939(6)°,γ= 79.3954(8)°,V= 1024.08(2) Å 3of compound (2). Structural analyses reveal that the title compounds are isostructural.« less

Unprecedented zeolite-like framework topology constructed from cages with 3-rings in a barium oxonitridophosphate.

PubMed

Sedlmaier, Stefan J; Döblinger, Markus; Oeckler, Oliver; Weber, Johannes; auf der Günne, Jörn Schmedt; Schnick, Wolfgang

2011-08-10

A novel oxonitridophosphate, Ba(19)P(36)O(6+x)N(66-x)Cl(8+x) (x ≈ 4.54), has been synthesized by heating a multicomponent reactant mixture consisting of phosphoryl triamide OP(NH(2))(3), thiophosphoryl triamide SP(NH(2))(3), BaS, and NH(4)Cl enclosed in an evacuated and sealed silica glass ampule up to 750 °C. Despite the presence of side phases, the crystal structure was elucidated ab initio from high-resolution synchrotron powder diffraction data (λ = 39.998 pm) applying the charge flipping algorithm supported by independent symmetry information derived from electron diffraction (ED) and scanning transmission electron microscopy (STEM). The compound crystallizes in the cubic space group Fm ̅3c (no. 226) with a = 2685.41(3) pm and Z = 8. As confirmed by Rietveld refinement, the structure comprises all-side vertex sharing P(O,N)(4) tetrahedra forming slightly distorted 3(8)4(6)8(12) cages representing a novel composite building unit (CBU). Interlinked through their 4-rings and additional 3-rings, the cages build up a 3D network with a framework density FD = 14.87 T/1000 Å(3) and a 3D 8-ring channel system. Ba(2+) and Cl(-) as extra-framework ions are located within the cages and channels of the framework. The structural model is corroborated by (31)P double-quantum (DQ) /single-quantum (SQ) and triple-quantum (TQ) /single-quantum (SQ) 2D correlation MAS NMR spectroscopy. According to (31)P{(1)H} C-REDOR NMR measurements, the H content is less than one H atom per unit cell. © 2011 American Chemical Society

Isolation of 1,4-Li(2)-C(6)H(4) and its reaction with [(Ph(3)P)AuCl].

PubMed

Flower, Kevin R; McGown, A T; Miles, Philip J; Pritchard, Robin G; Warren, John E

2010-04-14

The difficulty in generating 1,4-Li2-C6H4 utilising the lithium halogen exchange reaction on 1,4-Br2-C6H4, 1,4-I2-C6H4 and 1-Br-4-I-C6H4 is revisited and only on treatment of 1,4-I2-C6H4 with 2 molar equivalents of n-BuLi can 1,4-Li2-C6H4 1 be isolated in excellent yield. Treatment of 1 with two equivalents of [ClAu(PPh3)] gives [1,4-(Ph3PAu)2-C6H4] 2a in excellent yield. Subsequent treatment of 2a with 2.5 molar equivalents of PPh2Me, PPhMe2 or PMe3 affords the PPh3 substituted compounds [1,4-(LAu)2-C6H4] (L = PPh2Me 2b, PPhMe2 2c, PMe3 2d) in essentially quantitative yields. On treatment of 1,4-Br2-C6H4 or 1-Br-4-I-C6H4 with 2 molar equivalents of n-BuLi only mono-lithiation takes place to give 1-Br-4-Li-C6H4 3 as shown through the isolation of essentially 1:1 molar equivalents of Ph2PC6H4-4-Br and Ph2PBu on treatment with 2 molar equivalents of ClPPh2. Treatment of 3, prepared by lithium/iodine exchange on 1-Br-4-I-C6H4, with [ClAu(PPh3)] affords [(Ph3P)Au(C6H4-4-Br)] 4 as expected and in addition [(Ph3P)Au(n-Bu)(C6H4-4-Br)2] 5, indicating the straightforward chloride/aryl exchange at gold may proceed in competition with oxidative addition of the n-BuI, generated in the initial lithium/iodine exchange reaction, to some aurate complex Li[Au(C6H4-4-Br)2] 6 formed in situ followed by reductive elimination of Br-C6H4-4-n-Bu in a manner that mimics lithium diorganocuprate chemistry. All of the gold-containing compounds have been spectroscopically characterised by 1H and 31P-{1H} NMR and in addition compounds 2a-d and 5 by single crystal X-ray diffraction studies. The solid state structures observed for 2a-d are dictated by non-conventional hydrogen bonding and the packing requirements of the phosphine ligands. For 2a and 2b there is no close Au...Au approach, however for 2c and 2d the reduction in the number of phenyl rings allows the formation of Au...Au contacts. For 2c and 2d the extended structures appear to be helical chains with Au...Au contact parameters of 3.855(5) A and C-Au-Au-C 104.1(3)degrees for 2c and 3.139(4) A and C-Au-Au-C -92.0(2)degrees for 2d. The Au...Au approach in 2c is longer than is normally accepted for an AuAu contact and is dictated by ligand directed non-conventional hydrogen bonding to the aurated benzene ring and the pi-stacking requirements of the phosphine ligand. By comparison of the structures 2a-2d with other structures in the database it is evident that the aurophilic interaction is a poor supramolecular synthon in the presence of non-conventional hydrogen bond donors. Searches of the CCDC database suggest that the observed parameters for the Au...Au contact in 2c sit close to the cut-off point for observing this type of contact. In addition to aurophilic contacts and non-conventional hydrogen bonds there are a number of halogenated solvent C-Cl...Au contacts observed in the structures of 2a and 2d. The nature of these contacts have implications for the accepted van der Waals radius of gold which should be extended to 2 A.

Synthesis, crystal structure and study of magnetocaloric effect and single molecular magnetic behaviour in discrete lanthanide complexes.

PubMed

Adhikary, Amit; Sheikh, Javeed Ahmad; Biswas, Soumava; Konar, Sanjit

2014-06-28

The synthesis, crystal structure and magnetic properties of four polynuclear lanthanide coordination complexes having molecular formulae, [Gd3(2)(1)L(H2O)8(Cl)](Cl)4·10H2O (1), [Dy3L(2)(1)(H2O)9](Cl)5·6H2O (2) [Gd6L(2)(2)(HCO2)4(μ3-OH)4(DMF)6(H2O)2](Cl)2·4H2O (3) and [Dy6L(2)(2)(HCO2)4(μ3-OH)4(DMF)6(H2O)2](Cl)2·4H2O (4) (where H2L(1) = bis[(2-pyridyl)methylene]pyridine-2,6-dicarbohydrazide and H4L(2) = bis[2-hydroxy-benzylidene]pyridine-2,6-dicarbohydrazide) are reported. Structural investigation by X-ray crystallography reveals similar structural features for complexes 1 and 2 and they exhibit butterfly like shapes of the molecules. Non-covalent interactions between the molecules create double helical arrangements for both molecules. Complexes 3 and 4 are isostructural and the core structures feature four distorted hemi-cubanes connected by vertex sharing. Magnetic studies unveil significant magnetic entropy changes for complexes 1, 3 and slow relaxation of magnetization for both dysprosium analogues 2 and 4.

Comparative Shock-Tube Study of Autoignition and Plasma-Assisted Ignition of C2-Hydrocarbons

NASA Astrophysics Data System (ADS)

Kosarev, Ilya; Kindysheva, Svetlana; Plastinin, Eugeny; Aleksandrov, Nikolay; Starikovskiy, Andrey

2015-09-01

The dynamics of pulsed picosecond and nanosecond discharge development in liquid water, ethanol and hexane Using a shock tube with a discharge cell, ignition delay time was measured in a lean (φ = 0.5) C2H6:O2:Ar mixture and in lean (φ = 0.5) and stoichiometric C2H4:O2:Ar mixtures with a high-voltage nanosecond discharge and without it. The measured results were compared with the measurements made previously with the same setup for C2H6-, C2H5OH- and C2H2-containing mixtures. It was shown that the effect of plasma on ignition is almost the same for C2H6, C2H4 and C2H5OH. The reduction in time is smaller for C2H2, the fuel that is well ignited even without the discharge. Autoignition delay time was independent of the stoichiometric ratio for C2H6 and C2H4, whereas this time in stoichiometric C2H2- and C2H5OH-containing mixtures was noticeably shorter than that in the lean mixtures. Ignition after the discharge was not affected by a change in the stoichiometric ratio for C2H2 and C2H4, whereas the plasma-assisted ignition delay time for C2H6 and C2H5OH decreased as the equivalence ratio changed from 1 to 0.5. Ignition delay time was calculated in C2-hydrocarbon-containing mixtures under study by simulating separately discharge and ignition processes. Good agreement was obtained between new measurements and calculated ignition delay times.

Bluish-white-light-emitting diodes based on two-dimensional lead halide perovskite (C6H5C2H4NH3)2PbCl2Br2

NASA Astrophysics Data System (ADS)

Cai, Peiqing; Wang, Xiangfu; Seo, Hyo Jin; Yan, Xiaohong

2018-04-01

Bluish-white-light-emitting diodes (BWLEDs) are designed based on the two-dimensional mixed halide perovskite (C6H5C2H4NH3)2PbCl2Br2 at room temperature. Bluish-white electroluminescence devices were fabricated by a spin-coating method. The BWLEDs can be turned on at 4.9 V and depict a maximum luminance of ˜70 cd/m2 at 7 V. Low and room temperature photoluminescence spectra show the coexistence of free exciton and self-trapped exciton luminescence in a deformable lattice. The strategy of achieving white electroluminescence (EL) from mixed halide perovskite reported here can be applied to other two-dimensional perovskites to increase the optoelectronic efficiency of the device in the future.

Al/Cl2 molten salt battery

NASA Technical Reports Server (NTRS)

Giner, J.

1972-01-01

Molten salt battery has been developed with theoretical energy density of 5.2 j/kg (650 W-h/lb). Battery, which operates at 150 C, can be used in primary mode or as rechargeable battery. Battery has aluminum anode and chlorine cathode. Electrolyte is mixture of AlCl3, NaCl, and some alkali metal halide such as KCl.

Characterization of phenylpropanoid pathway genes within European maize (Zea mays L.) inbreds

PubMed Central

Andersen, Jeppe Reitan; Zein, Imad; Wenzel, Gerhard; Darnhofer, Birte; Eder, Joachim; Ouzunova, Milena; Lübberstedt, Thomas

2008-01-01

Background Forage quality of maize is influenced by both the content and structure of lignins in the cell wall. Biosynthesis of monolignols, constituting the complex structure of lignins, is catalyzed by enzymes in the phenylpropanoid pathway. Results In the present study we have amplified partial genomic fragments of six putative phenylpropanoid pathway genes in a panel of elite European inbred lines of maize (Zea mays L.) contrasting in forage quality traits. Six loci, encoding C4H, 4CL1, 4CL2, C3H, F5H, and CAD, displayed different levels of nucleotide diversity and linkage disequilibrium (LD) possibly reflecting different levels of selection. Associations with forage quality traits were identified for several individual polymorphisms within the 4CL1, C3H, and F5H genomic fragments when controlling for both overall population structure and relative kinship. A 1-bp indel in 4CL1 was associated with in vitro digestibility of organic matter (IVDOM), a non-synonymous SNP in C3H was associated with IVDOM, and an intron SNP in F5H was associated with neutral detergent fiber. However, the C3H and F5H associations did not remain significant when controlling for multiple testing. Conclusion While the number of lines included in this study limit the power of the association analysis, our results imply that genetic variation for forage quality traits can be mined in phenylpropanoid pathway genes of elite breeding lines of maize. PMID:18173847

Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

PubMed Central

2013-01-01

Background The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%. PMID:23289764

Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed.

PubMed

Olek, Malgorzata; Baron, Jerzy; Zukowski, Witold

2013-01-06

The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%.

Kinetics and Thermochemistry of the Cl((sup 2)P(sub J)) + C2Cl4 Association Reaction

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Wang, S.; Mckee, M. L.; Wine, P. H.

1997-01-01

A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the Cl(sup 2)P(sub j) + C2Cl4 association reaction as a function of temperature (231-390 K) and pressure (3-700 Torr) in nitrogen buffer gas. The reaction is found to be in the falloff regime between third and second order over the range of conditions investigated, although the second-order limit is approached at the highest pressures and lowest temperatures. At temperatures below 300 K, the association reaction is found to be irreversible on the experimental time scale of approximately 20 m-s. The kinetic data at T is less than 300 K have been employed to obtain falloff parameters in a convenient format for atmospheric modeling. At temperatures above 330 K, reversible addition is observed, thus allowing equilibrium constants for C2Cl5 formation and dissociation to be determined. Second- and third-law analyses of the equilibrium data lead to the following thermochemical parameters for the association reaction: Delta-H(298) = -18.1 +/- 1.3 kcal/mol, Delta-H(0) = -17.6 +/- 1.3 kcal/mol, and Delta-S(298) = -27.7 +/- 3.0 cal/mol.K. In conjunction with the well-known heats of formation of Cl((sup 2)P(sub j)) and C2Cl4 the above Delta-H values lead to the following heats of formation for C2Cl5, at 298 and 0 K: Delta-H(f,298) = 8.0 +/- 1.3 kcal/mol and Delta-H(f,0) = 8.1 +/- 1.5 kcal/mol. The kinetic and thermochemical parameters reported above are compared with other reported values, and the significance of reported association rate coefficients for understanding tropospheric chlorine chemistry is discussed.

A sodium–aluminum hybrid battery

DOE PAGES

Sun, Xiao-Guang; Zhang, Zhizhen; Guan, Hong Yu; ...

2017-03-07

We present novel hybrid batteries that are fabricated using an aluminum anode, a sodium intercalation cathode Na 3V 2(PO 4) 3 (NVP), and a sodium/aluminum dual salt electrolyte based on NaAlCl 4 and an eutectic mixture of 1-ethyl-3-methylimidazolium chloride (EMImC) and aluminum chloride. Cyclic voltammograms indicate that increasing the molar concentration of AlCl 3 in the electrolyte is beneficial to high coulombic efficiency of aluminum deposition/stripping, which, unfortunately, results in lower coulombic efficiency of sodium extraction/insertion in the cathode. Therefore, EMImC–AlCl 3 with a molar ratio of 1–1.1 is used for battery evaluation. The hybrid battery with 1.0 M NaAlClmore » 4 exhibits a discharge voltage of 1.25 V and a cathodic capacity of 99 mA h g -1 at a current rate of C/10. In addition, the hybrid battery exhibits good rate performance and long-term cycling stability while maintaining a high coulombic efficiency of 98%. It is also demonstrated that increasing salt concentration can further enhance the cycling performance of the hybrid battery. X-ray diffraction analysis of the NVP electrodes under different conditions confirms that the main cathode reaction is indeed Na extraction/insertion. Based on all earth-abundant elements, the new Na–Al hybrid battery is very attractive for stationary and grid energy storage applications.« less

A sodium–aluminum hybrid battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xiao-Guang; Zhang, Zhizhen; Guan, Hong Yu

We present novel hybrid batteries that are fabricated using an aluminum anode, a sodium intercalation cathode Na 3V 2(PO 4) 3 (NVP), and a sodium/aluminum dual salt electrolyte based on NaAlCl 4 and an eutectic mixture of 1-ethyl-3-methylimidazolium chloride (EMImC) and aluminum chloride. Cyclic voltammograms indicate that increasing the molar concentration of AlCl 3 in the electrolyte is beneficial to high coulombic efficiency of aluminum deposition/stripping, which, unfortunately, results in lower coulombic efficiency of sodium extraction/insertion in the cathode. Therefore, EMImC–AlCl 3 with a molar ratio of 1–1.1 is used for battery evaluation. The hybrid battery with 1.0 M NaAlClmore » 4 exhibits a discharge voltage of 1.25 V and a cathodic capacity of 99 mA h g -1 at a current rate of C/10. In addition, the hybrid battery exhibits good rate performance and long-term cycling stability while maintaining a high coulombic efficiency of 98%. It is also demonstrated that increasing salt concentration can further enhance the cycling performance of the hybrid battery. X-ray diffraction analysis of the NVP electrodes under different conditions confirms that the main cathode reaction is indeed Na extraction/insertion. Based on all earth-abundant elements, the new Na–Al hybrid battery is very attractive for stationary and grid energy storage applications.« less

Semiconducting perovskites (2-XC6H4C2H4NH3)2SnI4 (X = F, Cl, Br): steric interaction between the organic and inorganic layers.

PubMed

Xu, Zhengtao; Mitzi, David B; Dimitrakopoulos, Christos D; Maxcy, Karen R

2003-03-24

Two new semiconducting hybrid perovskites based on 2-substituted phenethylammonium cations, (2-XC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) (X = Br, Cl), are characterized and compared with the previously reported X = F compound, with a focus on the steric interaction between the organic and inorganic components. The crystal structure of (2-ClC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) is solved in a disordered subcell [C2/m, a = 33.781(7) A, b = 6.178(1) A, c = 6.190(1) A, beta = 90.42(3)(o), and Z = 2]. The structure is similar to the known (2-FC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) structure with regard to both the conformation of the organic cations and the bonding features of the inorganic sheet. The (2-BrC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) system adopts a fully ordered monoclinic cell [P2(1)/c, a = 18.540(2) A, b = 8.3443(7) A, c = 8.7795(7) A, beta = 93.039(1)(o), and Z = 2]. The organic cation adopts the anti conformation, instead of the gauche conformation observed in the X = F and Cl compounds, apparently because of the need to accommodate the additional volume of the bromo group. The steric effect of the bromo group also impacts the perovskite sheet, causing notable distortions, such as a compressed Sn-I-Sn bond angle (148.7(o), as compared with the average values of 153.3 and 154.8(o) for the fluoro and chloro compounds, respectively). The optical absorption features a substantial blue shift (lowest exciton peak: 557 nm, 2.23 eV) relative to the spectra of the fluoro and chloro compounds (588 and 586 nm, respectively). Also presented are transport properties for thin-film field-effect transistors (TFTs) based on spin-coated films of the two hybrid semiconductors.

Vitamins E and C Prevent DNA Double-strand Breaks in Peripheral Lymphocytes Exposed to Radiations from Iodine-131.

PubMed

Safaei, Mehdi; Jafarpour, Seyed Masoud; Mohseni, Mehran; Salimian, Morteza; Akbari, Hossein; Karami, Fateme; Aliasgharzadeh, Akbar; Farhood, Bagher

2018-01-01

Iodine-131 is used as a radiopharmaceutical to treat thyroid cancer. The current study aimed to evaluate the effects of vitamins E and C on the level of DNA double-strand breaks (DSBs) caused by Radioiodine-131 (I-131) in human lymphocytes. Whole blood samples from human volunteers were incubated with a certain concentration of vitamins. After 1-h incubation, the samples were incubated with 20 μCi I-131/2 mL (blood + NaCl) for 1 h. To evaluate the effects of antioxidants, lymphocytes were separated, and the mean DSBs/cell was measured for each sample through γ-H2AX assay. After 1-h incubation with 20 μCi I-131/2 mL (blood + NaCl), iodine-131 increased the level of DSBs by 102.9%, compared with the background group. Vitamins E and C reduced the level of DSBs by 21.5% and 36.4%, respectively. Using vitamins E and C as antioxidants can reduce the toxicity of I-131. Furthermore, vitamin C provided the more protection for DNA, compared with vitamin E.

Tenacibaculum litoreum sp. nov., isolated from tidal flat sediment.

PubMed

Choi, Dong Han; Kim, Yoon-Gon; Hwang, Chung Yeon; Yi, Hana; Chun, Jongsik; Cho, Byung Cheol

2006-03-01

A rod-shaped bacterium, designated CL-TF13T, was isolated from a tidal flat in Ganghwa, Korea. Analysis of the 16S rRNA gene sequence revealed an affiliation with the genus Tenacibaculum. The sequence similarities between CL-TF13T and type strains of members of the genus Tenacibaculum were from 94.2 to 97.4%. Cells were motile by means of gliding. Strain CL-TF13T grew on solid medium as pale-yellow colonies with an irregular spreading edge. The strain was able to grow in NaCl at a range of 3-5%. They grew within a temperature range of 5-40 degrees C and at pH range of 6-10. The major fatty acids were summed feature 3 (C(16:1)omega7c and/or iso-C(15:0) 2-OH, 19.6%), iso-C(15:0) (18.8%) and iso-C(17:0) 3-OH (13.6%). Fatty acids such as C(18:3)omega6c (6,9,12) (1.5%) and summed feature 4 (iso I- and/or anteiso B-C(17:1), 1.3%) were uniquely found in minor quantities in CL-TF13T among Tenacibaculum species. The DNA G + C content was 30 mol%. According to physiological data, fatty-acid composition and 16S rRNA gene sequence, CL-TF13T could be assigned to the genus Tenacibaculum but distinguished from the recognized species of the genus. Therefore, strain CL-TF13T (= KCCM 42115T = JCM 13039T) represents a novel species, for which the name Tenacibaculum litoreum sp. nov. is proposed.

Multiple alterations of canalicular membrane transport activities in rats with CCl(4)-induced hepatic injury.

PubMed

Song, Im-Sook; Lee, Young-Mi; Chung, Suk-Jae; Shim, Chang-Koo

2003-04-01

The influence of CCl(4)-induced experimental hepatic injury (CCl(4)-EHI) on the expression and transport activities of primary active transporters on the canalicular membrane, including P-glycoprotein (P-gp), a bile salt export pump (Bsep) and a multidrug resistance associated protein2 (Mrp2), was assessed. CCl(4)-EHI was induced by an intraperitoneal injection of CCl(4) to rats at a dose of 1 ml/kg 24 h prior to the preparation of canalicular liver plasma membrane (cLPM) vesicles and pharmacokinetic studies. The expression of each transporter was measured for the vesicles via Western blot analysis at 6, 12, 24, 36, and 48 h after the injection of CCl(4). The in vivo canalicular excretion clearance (CL(exc)) of [(3)H]daunomycin, [(3)H]taurocholate and [(3)H]17beta-estradiol-17beta-D-glucuronide (E(2)17betaG), representative substrates of P-gp, Bsep, and Mrp2, respectively, was determined following an i.v. infusion to rats. The uptake of each substrate into cLPM vesicles in the presence of ATP was also measured by a rapid filtration technique. As the result of the CCl(4)-EHI, the protein level of transporters was altered as a function of time in multiple manners; it was increased by 3.6-fold for P-gp, unchanged for Bsep, and decreased by 73% for Mrp2 at 24 h. The in vivo CL(exc) and the intrinsic uptake clearance into cLPM vesicles (CL(int)) at 24 h after the CCl(4) injection (CCl(4)-EHI(24 h)) were also influenced by the EHI in a similar manner; they were increased by 1.8- and 1.9-fold for daunomycin, unchanged for taurocholate, and decreased by 41 and 39% for E(2)17betaG, respectively, consistent with multiple alterations in the expression of the relevant transporters.

Class A Sodalites: Silver, Sodium, Halosodalites

DTIC Science & Technology

1992-05-15

always possessed Ag 5s and Ag 5 p characteristics while the HOMO orbitals were mixtures of mainly X np (X n = Cl 3, Br 4,15) and Ag 4d orbitals with some...Small Particles, J. Wiley & Sans: N . Y., 1983, p . 132. 1012. Calzaferri, 0.; Forss, L; Hugentobler, T.; Kamber, L ICONC and INPUTC, Fortran software for...nw q U . * e c ,s , aD a m ,,m", h u s ( a in m n ntfu hIh,, - , ,e - - - - . - .. - . ; -.T -?- -/ ~ ~ ~~ w Wtmuf.,cua sltl ro r l fut"O. to w

The CNET Automated Budget System (CABS) IV.

DTIC Science & Technology

1982-12-01

r RD-A124 173 THE CNET RUTOMATED BUDGET SYSTEM (CABS) IV(U) TRAINING 1/ ANALYSIS AND EVALUATION GROUP (NAVY) ORLANDO FL G N HODAK ET AL. DEC 82 TREG ...Ix ,A Ix A to 0 A a u H o••# •N U~~dl1 0-4 IL : IL N• €: . of, 4A "’ u j ilC x: 11-. ofl 11. 0 14 l of •joft -9 I C)l 0l 1 V) 0-0 r t 0 . Vl L-0C

Identification of the fatty acid activation site on human ClC-2.

PubMed

Cuppoletti, John; Tewari, Kirti P; Chakrabarti, Jayati; Malinowska, Danuta H

2017-06-01

Fatty acids (including lubiprostone and cobiprostone) are human ClC-2 (hClC-2) Cl - channel activators. Molecular and cellular mechanisms underlying this activation were examined. Role of a four-amino acid PKA activation site, RGET 691 , of hClC-2 was investigated using wild-type (WT) and mutant (AGET, RGEA, and AGAA) hClC-2 expressed in 293EBNA cells as well as involvement of PKA, intracellular cAMP concentration ([cAMP] i ), EP 2 , or EP 4 receptor agonist activity. All fatty acids [lubiprostone, cobiprostone, eicosatetraynoic acid (ETYA), oleic acid, and elaidic acid] caused significant rightward shifts in concentration-dependent Cl - current activation (increasing EC 50 s) with mutant compared with WT hClC-2 channels, without changing time and voltage dependence, current-voltage rectification, or methadone inhibition of the channel. As with lubiprostone, cobiprostone activation of hClC-2 occurred with PKA inhibitor (myristoylated protein kinase inhibitor) present or when using double PKA activation site (RRAA 655 /RGEA 691 ) mutant. Cobiprostone did not activate human CFTR. Fatty acids did not increase [cAMP] i in hClC-2/293EBNA or T84 cells. Using T84 CFTR knockdown cells, cobiprostone increased hClC-2 Cl - currents without increasing [cAMP] i, while PGE 2 and forskolin-IBMX increased both. Fatty acids were not agonists of EP 2 or EP 4 receptors. L-161,982, a supposed EP 4 -selective inhibitor, had no effect on lubiprostone-activated hClC-2 Cl - currents but significantly decreased T84 cell barrier function measured by transepithelial resistance and fluorescent dextran transepithelial movement. The present findings show that RGET 691 of hClC-2 (possible binding site) plays an important functional role in fatty acid activation of hClC-2. PKA, [cAMP] i , and EP 2 or EP 4 receptors are not involved. These studies provide the molecular basis for fatty acid regulation of hClC-2. Copyright © 2017 the American Physiological Society.

Lubiprostone Activates CFTR, but not ClC-2, via the Prostaglandin Receptor (EP4)

PubMed Central

Norimatsu, Yohei; Moran, Aurelia R.; MacDonald, Kelvin D.

2012-01-01

The goal of this study was to determine the mechanism of lubiprostone activation of epithelial chloride transport. Lubiprostone is a bicyclic fatty acid approved for the treatment of constipation [1]. There is uncertainty, however, as to how lubiprostone increases epithelial chloride transport. Direct stimulation of ClC-2 and CFTR chloride channels as well as stimulation of these channels via the EP4 receptor has been described [2; 3; 4; 5]. To better define this mechanism, two-electrode voltage clamp was used to assay Xenopus oocytes expressing ClC-2, with or without co-expression of the EP4 receptor or β adrenergic receptor (βAR), for changes in conductance elicited by lubiprostone. Oocytes co-expressing CFTR and either βAR or the EP4 receptor were also studied. In oocytes co-expressing ClC-2 and βAR conductance was stimulated by hyperpolarization and acidic pH (pH=6), but there was no response to the β adrenergic agonist, isoproterenol. Oocytes expressing ClC-2 only or co-expressing ClC-2 and EP4 did not respond to the presence of 0.1, 1, or 10 µM lubiprostone in the superperfusate. Oocytes co-expressing CFTR and βAR did not respond to hyperpolarization, acidic pH, or 1µM lubiprostone. However, conductance was elevated by isoproterenol and inhibited by CFTRinh172. Co-expression of CFTR and EP4 resulted in lubiprostone-stimulated conductance, which was also sensitive to CFTRinh172. The EC50 for lubiprostone mediated CFTR activation was ~ 10 nM. These results demonstrate no direct action of lubiprostone on either ClC-2 or CFTR channels expressed in oocytes. However, the results confirm that CFTR can be activated by lubiprostone via the EP4 receptor in oocytes. PMID:22960173

Supply Chain Resilience: Assessing Resilience over the Life Cycle of Capital Equipment

DTIC Science & Technology

2014-07-09

Purposes): [] CRADA (Cooperative Research and Development Agreement) exists [] Photo/ Video Opportunities [] STEM -outreach Related [] New Invention...Recovery C9 10.6 / 0.7 9.8 / -1.1 Dispersion ClO 8.4 13.4 15.3 /11.0 Collaboration Cll -0.1 I -10.5 3.6 / -9.0 Organization Cl2 6.3 / -3.2 Security C l3

Optical resolution of {pi}-thiophene complexes (C{sub 6}Me{sub 6}) Ru(2-RC{sub 4}H{sub 3}S){sup 2+} and related studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dailey, K.K.; Rauchfuss, T.B.

Diasteriomeric iminium thiolato complexes were prepared by the addition of S-(-)-{alpha}-methylbenzylamine to the {pi}-thiophene complexes [(C{sub 6}Me{sub 6})Ru(2-RC{sub 4}H{sub 3}S)]{sup 2+}, where R = Me(1{sup 2+}), CH{sub 2}OH (3{sup 2+}), and 2-C{sub 4}H{sub 3}S(6{sup 2+}). After chromatographic separation, the diastereomers were treated with HOTf to generate optically pure {pi}-thiophene complexes. The absolute configuration of [(C{sub 6}Me{sub 6})RuSCMeC{sub 2}H{sub 2}(CHNHCHMePh)]OTf, (-)-2(OTf), was determined by a single-crystal X-ray diffraction; the monohydrate crystallized in the acentric space group P2{sub 1}2{sub 1}2{sub 1}. Base hydrolysis of (-)-1{sup 2+} gave the formyl thiolato complex (-)-9{sub kin}, which isomerized to (+)-9{sub therm} with inversion of configurationmore » at Ru, as indicated by circular dichroism measurements. The methyl ester of the amino acid (L)-phenylalanine was shown to add to (C{sub 6}Me{sub 6})Ru(C{sub 4}H{sub 4}S){sup 2+} to give a 2:1 mixture of diastereomeric iminium thiolato complexes. 19 refs., 3 figs., 2 tabs.« less

Hickam AFB, Hawaii Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

DTIC Science & Technology

1985-04-01

ZkAN~,I EATV A. TO RELATIVE HUMIDITY -- EAT’E~SE; VIC /MAL I.I 2n 4CK A A F H---- 74-337 STATION STATION NAME PERIOD CUMULATIVE PERCENTAGE FREQUENCY...AL 1 li 9 o G l O 1 0 . 1; 99 .9 7 92 -6 71.2 4 1’_.1 l S 1 67 . 72 2- ] USAFETAC F 0.87-5 (OL A) ....... -LCAIAL CL!’"ATCL3Y -sRANCM EATV - c L r TAC

Alkali metal complexes of sterically demanding amino-functionalized secondary phosphanide ligands.

PubMed

Izod, Keith; Stewart, John C; Clegg, William; Harrington, Ross W

2007-01-14

The reaction between {(Me(3)Si)(2)CH}PCl(2) (4) and one equivalent of either [C(6)H(4)-2-NMe(2)]Li or [2-C(5)H(4)N]ZnCl, followed by in situ reduction with LiAlH(4) gives the secondary phosphanes {(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))PH (5) and {(Me(3)Si)(2)CH}(2-C(5)H(4)N)PH (6) in good yields as colourless oils. Metalation of 5 with Bu(n)Li in THF gives the lithium phosphanide [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]Li(THF)(2)] (7), which undergoes metathesis with either NaOBu(t) or KOBu(t) to give the heavier alkali metal derivatives [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]Na(tmeda)] (8) and [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]K(pmdeta)] (9) after recrystallization in the presence of the corresponding amine co-ligand [tmeda = N,N,N',N'-tetramethylethylenediamine, pmdeta = N,N,N',N'',N''-pentamethyldiethylenetriamine]. The pyridyl-functionalized phosphane 6 undergoes deprotonation on treatment with Bu(n)Li to give a red oil corresponding to the lithium compound [{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]Li (10) which could not be crystallized. Treatment of this oil with NaOBu(t) gives the sodium derivative [{[{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]Na}(2) x (Et(2)O)](2) (11), whilst treatment of with KOBu(t), followed by recrystallization in the presence of pmdeta gives the complex [[{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]K(pmdeta)](2) (12). Compounds 5-12 have been characterised by (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectroscopy and elemental analyses; compounds 7-9, and 12 have additionally been characterised by X-ray crystallography. Compounds 7-9 crystallize as discrete monomers, whereas 11 crystallizes as an unusual dimer of dimers and 12 crystallizes as a dimer with bridging pyridyl-phosphanide ligands.

NS1643 Interacts around L529 of hERG to Alter Voltage Sensor Movement on the Path to Activation

PubMed Central

Guo, Jiqing; Cheng, Yen May; Lees-Miller, James P.; Perissinotti, Laura L.; Claydon, Tom W.; Hull, Christina M.; Thouta, Samrat; Roach, Daniel E.; Durdagi, Serdar; Noskov, Sergei Y.; Duff, Henry J.

2015-01-01

Activators of hERG1 such as NS1643 are being developed for congenital/acquired long QT syndrome. Previous studies identify the neighborhood of L529 around the voltage-sensor as a putative interacting site for NS1643. With NS1643, the V1/2 of activation of L529I (−34 ± 4 mV) is similar to wild-type (WT) (−37 ± 3 mV; P > 0.05). WT and L529I showed no difference in the slope factor in the absence of NS1643 (8 ± 0 vs. 9 ± 0) but showed a difference in the presence of NS1643 (9 ± 0.3 vs. 22 ± 1; P < 0.01). Voltage-clamp-fluorimetry studies also indicated that in L529I, NS1643 reduces the voltage-sensitivity of S4 movement. To further assess mechanism of NS1643 action, mutations were made in this neighborhood. NS1643 shifts the V1/2 of activation of both K525C and K525C/L529I to hyperpolarized potentials (−131 ± 4 mV for K525C and −120 ± 21 mV for K525C/L529I). Both K525C and K525C/K529I had similar slope factors in the absence of NS1643 (18 ± 2 vs. 34 ± 5, respectively) but with NS1643, the slope factor of K525C/L529I increased from 34 ± 5 to 71 ± 10 (P < 0.01) whereas for K525C the slope factor did not change (18 ± 2 at baseline and 16 ± 2 for NS1643). At baseline, K525R had a slope factor similar to WT (9 vs. 8) but in the presence of NS1643, the slope factor of K525R was increased to 24 ± 4 vs. 9 ± 0 mV for WT (P < 0.01). Molecular modeling indicates that L529I induces a kink in the S4 voltage-sensor helix, altering a salt-bridge involving K525. Moreover, docking studies indicate that NS1643 binds to the kinked structure induced by the mutation with a higher affinity. Combining biophysical, computational, and electrophysiological evidence, a mechanistic principle governing the action of some activators of hERG1 channels is proposed. PMID:25809253

Catalytic Silylation of N2 and Synthesis of NH3 and N2H4 by Net Hydrogen Atom Transfer Reactions Using a Chromium P4 Macrocycle.

PubMed

Kendall, Alexander J; Johnson, Samantha I; Bullock, R Morris; Mock, Michael T

2018-02-21

We report the first discrete molecular Cr-based catalysts for the reduction of N 2 . This study is focused on the reactivity of the Cr-N 2 complex, trans-[Cr(N 2 ) 2 (P Ph 4 N Bn 4 )] (P 4 Cr(N 2 ) 2 ), bearing a 16-membered tetraphosphine macrocycle. The architecture of the [16]-P Ph 4 N Bn 4 ligand is critical to preserve the structural integrity of the catalyst. P 4 Cr(N 2 ) 2 was found to mediate the reduction of N 2 at room temperature and 1 atm pressure by three complementary reaction pathways: (1) Cr-catalyzed reduction of N 2 to N(SiMe 3 ) 3 by Na and Me 3 SiCl, affording up to 34 equiv N(SiMe 3 ) 3 ; (2) stoichiometric reduction of N 2 by protons and electrons (for example, the reaction of cobaltocene and collidinium triflate at room temperature afforded 1.9 equiv of NH 3 , or at -78 °C afforded a mixture of NH 3 and N 2 H 4 ); and (3) the first example of NH 3 formation from the reaction of a terminally bound N 2 ligand with a traditional H atom source, TEMPOH (2,2,6,6-tetramethylpiperidine-1-ol). We found that trans-[Cr( 15 N 2 ) 2 (P Ph 4 N Bn 4 )] reacts with excess TEMPOH to afford 1.4 equiv of 15 NH 3 . Isotopic labeling studies using TEMPOD afforded ND 3 as the product of N 2 reduction, confirming that the H atoms are provided by TEMPOH.

Enzymological mechanism for the regulation of lanthanum chloride on flavonoid synthesis of soybean seedlings under enhanced ultraviolet-B radiation.

PubMed

Fan, Caixia; Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2014-01-01

In order to probe into the enzymological mechanism for the regulation of lanthanum chloride (LaCl3) on flavonoid synthesis in plants under enhanced ultraviolet-B (UV-B) radiation, the effects of LaCl₃ (20 and 60 mg l(-1)) on the content of flavonoids as well as the activities of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate : coenzyme A ligase (4CL), and chalcone synthase (CHS) in soybean seedlings under enhanced UV-B radiation (2.6 and 6.2 kJ m(-2) day(-1)) were investigated. Enhanced UV-B radiation (2.6 and 6.2 kJ m(-2) day(-1)) caused the increase in the content of flavonoids as well as the activities of PAL, C4H, 4CL, and CHS in soybean seedlings. The treatment of 20 mg l(-1) LaCl₃ also efficiently increased these indices, which promoted the flavonoid synthesis and provided protective effects for resisting enhanced UV-B radiation. On the contrary, the treatment of 60 mg l(-1) LaCl₃ decreased the content of flavonoids as well as the activities of C4H, 4CL, and CHS in soybean seedlings except increasing the activity of PAL, which were not beneficial to the flavonoid synthesis and provided negative effects for resisting enhanced UV-B radiation. In conclusion, enhanced UV-B radiation caused the increase in the flavonoid synthesis by promoting the activities of PAL, C4H, 4CL, and CHS in soybean seedlings. The treatment of LaCl₃ could change flavonoid synthesis in soybean seedlings under enhanced UV-B radiation by regulating the activities of PAL, C4H, 4CL, and CHS, which is an enzymological mechanism for the regulation of LaCl₃ on flavonoid synthesis in plants under enhanced UV-B radiation.

Formaldehyde-aminoguanidine condensation and aminoguanidine self-condensation products: syntheses, crystal structures and characterization.

PubMed

Buvaylo, Elena A; Kokozay, Vladimir N; Strutynska, Nataliia Yu; Vassilyeva, Olga Yu; Skelton, Brian W

2018-02-01

Guanidine is the functional group on the side chain of arginine, one of the fundamental building blocks of life. In recent years, a number of compounds based on the aminoguanidine (AG) moiety have been described as presenting high anticancer activities. The product of condensation between two molecules of AG and one molecule of formaldehyde was isolated in the protonated form as the dinitrate salt (systematic name: 2,8-diamino-1,3,4,6,7,9-hexaazanona-1,8-diene-1,9-diium dinitrate), C 3 H 14 N 8 2+ ·2NO 3 - , (I). The cation lacks crystallographically imposed symmetry and comprises two terminal planar guanidinium groups, which share an N-C-N unit. Each cation in (I) builds 14 N-H...O hydrogen bonds and is separated from adjacent cations by seven nitrate anions. The AG self-condensation reaction in the presence of copper(II) chloride and chloride anions led to the formation of the organic-inorganic hybrid 1,2-bis(diaminomethylidene)hydrazine-1,2-diium tetrachloridocuprate(II), (C 2 H 10 N 6 )[CuCl 4 ], (II). Its asymmetric unit is composed of half a diprotonated 1,2-bis(diaminomethylidene)hydrazine-1,2-diium dication and half a tetrachloridocuprate(II) dianion, with the Cu II atom situated on a twofold rotation axis. The planar guanidinium fragments in (II) have their planes twisted by approximately 77.64 (5)° with respect to each other. The tetrahedral [CuCl 4 ] 2- anion is severely distorted and its pronounced `planarity' must originate from its involvement in multiple N-H...Cl hydrogen bonds. It was reported that [CuCl 4 ] 2- anions, with a trans-Cl-Cu-Cl angle (Θ) of ∼140°, are yellow-green at room temperature, with the colour shifting to a deeper green as Θ increases and toward orange as Θ decreases. Brown salt (II), with a Θ value of 142.059 (8)°, does not fit the trend, which emphasizes the need to take other structural factors into consideration. In the crystal of salt (II), layers of cations and anions alternate along the b axis, with the minimum Cu...Cu distance being 7.5408 (3) Å inside a layer. The structures of salts (I) and (II) were substantiated via spectroscopic data. The endothermic reaction involved in the thermal decomposition of (I) requires additional oxygen. The title salts may be useful for the screening of new substances with biological activity.

Solubility of pyromorphite Pb 5(PO 4) 3Cl at 5–65°C and its experimentally determined thermodynamic parameters

DOE PAGES

Topolska, Justyna; Manecki, Maciej; Bajda, Tomasz; ...

2016-03-19

Here, the solubility of synthetic pyromorphite Pb 5(PO 4) 3Cl was determined in a series of dissolution experiments conducted at 5–65 °C and at pH = 2.0. The equilibrium was established within 4 months. The dissolution of pyromorphite was congruent at all the temperatures, and the measured solubility product log K sp,298 for the dissolution reaction: Pb 5(PO 4) 3Cl ⇌ 5Pb 2+ + 3PO 4 3- + Cl - was determined to be –79.6 ± 0.15. The equilibrium ion activity product of pyromorphite increased with temperature, indicating a positive enthalpy of the dissolution reaction in the temperature range frommore » 5 to 65 °C. The temperature dependence of the log K sp was nonlinear: log K sp = A – B/T + D log(T), where A = 478.77 ± 136.62, B = 29,378 ± 6215, and D = –185.81 ± 46.77. This allowed for calculation of ΔG° r = 454.0 ± 1.7 kJ·mol –1, ΔH° r = 101.8 ± 6.0 J·mol –1·K –1, ΔC° p,r = –1545 ± 388.9 J·mol –1·K –1, and ΔS° r = –1181 ± 382 J·mol –1·K –1 of the dissolution reaction. Using these values and the published standard state quantities for constituent ions, the values of ΔG° f = –3764.3 ± 3.5 kJ·mol –1, ΔH° f = –4108.4 ± 7.9 J·mol –1·K –1, S° f = 622 ± 382 J·mol –1·K –1, and C° pf = 402 ± 398 J·mol –1·K –1 were calculated for synthetic pyromorphite Pb 5(PO 4) 3Cl.« less

Crystal structure of fac-tri-carbonyl-chlorido-bis-(4-hy-droxy-pyridine)-rhenium(I)-pyridin-4(1H)-one (1/1).

PubMed

Argibay-Otero, Saray; Carballo, Rosa; Vázquez-López, Ezequiel M

2017-10-01

The asymmetric unit of the title compound, [ReCl(C 5 H 5 NO) 2 (CO) 3 ]·C 5 H 5 NO, contains one mol-ecule of the complex fac -[ReCl(4-pyOH) 2 (CO) 3 ] (where 4-pyOH represents 4-hy-droxy-pyridine) and one mol-ecule of pyridin-4(1 H )-one (4-HpyO). In the mol-ecule of the complex, the Re atom is coordinated to two N atoms of the two 4-pyOH ligands, three carbonyl C atoms, in a facial configuration, and the Cl atom. The resulting geometry is slightly distorted octa-hedral. In the crystal structure, both fragments are associated by hydrogen bonds; two 4-HpyO mol-ecules bridge between two mol-ecules of the complex using the O=C group as acceptor for two different HO- groups of coordinated 4-pyOH from two neighbouring metal complexes. The resulting square arrangements are extented into infinite chains by hydrogen bonds involving the N-H groups of the 4-HpyO mol-ecule and the chloride ligands. The chains are further stabilized by π-stacking inter-actions.

Virus purification by CsCl density gradient using general centrifugation.

PubMed

Nasukawa, Tadahiro; Uchiyama, Jumpei; Taharaguchi, Satoshi; Ota, Sumire; Ujihara, Takako; Matsuzaki, Shigenobu; Murakami, Hironobu; Mizukami, Keijirou; Sakaguchi, Masahiro

2017-11-01

Virus purification by cesium chloride (CsCl) density gradient, which generally requires an expensive ultracentrifuge, is an essential technique in virology. Here, we optimized virus purification by CsCl density gradient using general centrifugation (40,000 × g, 2 h, 4 °C), which showed almost the same purification ability as conventional CsCl density gradient ultracentrifugation (100,000 × g, 1 h, 4 °C) using phages S13' and φEF24C. Moreover, adenovirus strain JM1/1 was also successfully purified by this method. We suggest that general centrifugation can become a less costly alternative to ultracentrifugation for virus purification by CsCl densiy gradient and will thus encourage research in virology.

Evaluate Rijsimulator-Instellingen Voor de DAF YA-4440 (Evaluation Drive Simulator Settings for DAF YA-4440)

DTIC Science & Technology

1991-10-01

waarbij: 0c1 staat voor de beginsnclhcid; cl = 24 K1 C= (3/25) K2 C= 5 K4 Merk op dat 0o cxponenticcl afhankelijk is van t. TNO-rapport Pagina 9 Voor (KI...gegeven: cgt) = sqrt(ci/C3)*tan(arctan(sqr((c 3/c1 )*w0 )) - sqrl(c1 *C3)*t/C4) ( 9 ) waarbij: cl= -24 K, C= 3 1(3/500 C4= 5 K4~ Merk op dat (o niet-lincair...wcrgegevcn. Omdat K, kiciner is dan K4 heeft con kicine absolute verandering in K, grotere gevolgen voor de UDB-uitrolcurve dan en kieinc verandoring in

Solubility relations in the system potassium chloride-ferrous chloride-water between 25 and 75.degree.C at 1 atm

USGS Publications Warehouse

Chou, I.-Ming; Phan, L.D.

1986-01-01

Solubility relations in the ternary system KCl-FeCl2-H2O have been determined by means of the visual polythermal method at 1 atm from 18 to 75??C along 10 composition lines. Solubilities of sylvite were measured along five composition lines defined by mixing KCl with five aqueous FeCl2 solutions containing 10, 20, 30, 38, and 45 wt % of FeCl2, respectively. Solubilities of FeCl2??4H2O were also determined along five composition lines defined by mixing FeCl2??4H2O with five aqueous KCl solutions containing 5, 10, 14.98, 19.97, and 24.99 wt % KCl, respectively. The maximum uncertainties in these measurements are ??0.02 wt % in KCl, ??0.15 wt % in FeCl2, and ??0.15??C. The data along each composition line were regressed to a smooth curve. The maximum deviations of the measured solubilities from the smoothed curves are 0.22 wt % in KCl and 0.12 wt % in FeCl2. Isothermal solubilities of sylvite and FeCl2??4H2O were calculated from these smoothed curves at 25, 40, 50, 60, 70, and 75??C.

Phase Equilibria and Transport Properties in the Systems AgNO3/RCN/H2O. R = CH3, C2H5, C3H7, C4H,, C6H5, and C6H5CH2

NASA Astrophysics Data System (ADS)

Das, Surjya P.; Wittekopf, Burghard; Weil, Konrad G.

1988-11-01

Silver nitrate can form homogeneous liquid phases with some organic nitriles and water, even when there is no miscibility between the pure liquid components. We determined the shapes of the single phase regions in the ternary phase diagram for the following systems: silver nitrate /RCN /H2O with R =CH3, C3H7, C6H5, and C6H5CH2 at room temperature and for R =C6H5 also at 60 °C and O °C. Furthermore we studied kinematic viscosities, electrical conductivities, and densities of mixtures containing silver nitrate, RCN, and water with the mole ratios X /4 /1 (0.2≦ X ≦S 3.4). In these cases also R = C2H5 and C4H9 were studied. The organic nitriles show different dependences of viscosity and conductivity on the silver nitrate content from the aliphatic ones.

Synthesis, characterization and DNA-binding studies of mono and heterobimetallic complexes Cu sbnd Sn 2/Zn sbnd Sn 2 and their DNA cleavage activity

NASA Astrophysics Data System (ADS)

Arjmand, Farukh; Sayeed, Fatima

2010-02-01

Heterobimetallic complexes C 6H 24N 4O 6CuSn 2Cl 63, C 6H 24N 4O 6ZnSn 2Cl 64 have been synthesized from their monometallic analogs C 6H 16N 4O 2CuCl 21, C 6H 16N 4O 2ZnCl 22, and were characterized by various spectroscopic and analytical methods. The complexes 1-4 reveal an octahedral geometry for both central metal ions Cu/Zn as well as for Sn metal ion. The interaction of complexes 1-4 with CT-DNA, were investigated by using absorption, emission, cyclic voltammetry, viscometry and DNA cleavage studies. The emission quenching of 3 and 4 by [Fe(CN) 6] 4- depressed greatly when bound to CT-DNA. The results of spectroscopic, viscometric and cyclic voltammetry of complexes 3 and 4 revealed electrostatic mode of binding of the complexes with CT-DNA. These results revealed that 4 bind more avidly in comparison to 3 with CT-DNA. Gel electrophoresis of DNA with complexes 3 and 4 demonstrated that the complexes exhibit excellent cleavage activity under physiological conditions.

Sugarcane bagasse pretreatment using three imidazolium-based ionic liquids; mass balances and enzyme kinetics

PubMed Central

2012-01-01

Background Effective pretreatment is key to achieving high enzymatic saccharification efficiency in processing lignocellulosic biomass to fermentable sugars, biofuels and value-added products. Ionic liquids (ILs), still relatively new class of solvents, are attractive for biomass pretreatment because some demonstrate the rare ability to dissolve all components of lignocellulosic biomass including highly ordered (crystalline) cellulose. In the present study, three ILs, 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), 1-ethyl-3-methylimidazolium chloride ([C2mim]Cl), 1-ethyl-3-methylimidazolium acetate ([C2mim]OAc) are used to dissolve/pretreat and fractionate sugarcane bagasse. In these IL-based pretreatments the biomass is completely or partially dissolved in ILs at temperatures greater than 130°C and then precipitated by the addition of an antisolvent to the IL biomass mixture. For the first time mass balances of IL-based pretreatments are reported. Such mass balances, along with kinetics data, can be used in process modelling and design. Results Lignin removals of 10% mass of lignin in bagasse with [C4mim]Cl, 50% mass with [C2mim]Cl and 60% mass with [C2mim]OAc, are achieved by limiting the amount of water added as antisolvent to 0.5 water:IL mass ratio thus minimising lignin precipitation. Enzyme saccharification (24 h, 15FPU) yields (% cellulose mass in starting bagasse) from the recovered solids rank as: [C2mim]OAc(83%) > >[C2mim]Cl(53%) = [C4mim]Cl(53%). Composition of [C2mim]OAc-treated solids such as low lignin, low acetyl group content and preservation of arabinosyl groups are characteristic of aqueous alkali pretreatments while those of chloride IL-treated solids resemble aqueous acid pretreatments. All ILs are fully recovered after use (100% mass as determined by ion chromatography). Conclusions In all three ILs regulated addition of water as an antisolvent effected a polysaccharide enriched precipitate since some of the lignin remained dissolved in the aqueous IL solution. Of the three IL studied [C2mim]OAc gave the best saccharification yield, material recovery and delignification. The effects of [C2mim]OAc pretreatment resemble those of aqueous alkali pretreatments while those of [C2mim]Cl and [C4mim]Cl resemble aqueous acid pretreatments. The use of imidazolium IL solvents with shorter alkyl chains results in accelerated dissolution, pretreatment and degradation. PMID:22920045

Nonenzymatic and enzymatic hydrolysis of alkyl halides: A theoretical study of the SN2 reactions of acetate and hydroxide ions with alkyl chlorides

PubMed Central

Maulitz, Andreas H.; Lightstone, Felice C.; Zheng, Ya-Jun; Bruice, Thomas C.

1997-01-01

The SN2 displacements of chloride ion from CH3Cl, C2H5Cl, and C2H4Cl2 by acetate and hydroxide ions have been investigated, using ab initio molecular orbital theory at the HF/6–31+G(d), MP2/6–31+G(d), and MP4/6–31+G(d) levels of theory. The central barriers (calculated from the initial ion–molecule complex) of the reactions, the differences of the overall reaction energies, and the geometries of the transition states are compared. Essential stereochemical changes before and after the displacement reactions are described for selected cases. The gas phase reactions of hydroxide with CH3Cl, C2H5Cl, and C2H4Cl2 have no overall barrier, but there is a small overall barrier for the reactions of acetate with CH3Cl, C2H5Cl, and C2H4Cl2. A self-consistent reaction field solvation model was used to examine the SN2 reactions between methyl chloride and hydroxide ion and between 1,2-dichloroethane and acetate in solution. As expected, the reactions in polar solvent have a large barrier. However, the transition state structures determined by ab initio calculations change only slightly in the presence of a highly polar solvent as compared with the gas phase. We also calibrated the PM3 method for future study of an enzymatic SN2 displacement of halogen. PMID:9192609

Dithiolato- and halogenido-bridged nickel-iron complexes related to the active site of [NiFe]-H2ases: preparation, structures, and electrocatalytic H2 production.

PubMed

Song, Li-Cheng; Han, Xiao-Feng; Chen, Wei; Li, Jia-Peng; Wang, Xu-Yong

2017-08-14

A new series of the structural and functional models for the active site of [NiFe]-H 2 ases has been prepared by a simple and convenient synthetic route. Thus, treatment of diphosphines RN(PPh 2 ) 2 (1a, R = p-MeC 6 H 4 CH 2 ; 1b, R = EtO 2 CCH 2 ) with an equimolar NiCl 2 ·6H 2 O, NiBr 2 ·3H 2 O, and NiI 2 in refluxing CH 2 Cl 2 /MeOH or EtOH gave the mononuclear Ni complexes RN(PPh 2 ) 2 NiX 2 (2a, R = p-MeC 6 H 4 CH 2 , X = Cl; 2b, R = EtO 2 CCH 2 , X = Cl; 3a, R = p-MeC 6 H 4 CH 2 , X = Br; 3b, R = EtO 2 CCH 2 , X = Br; 4a, R = p-MeC 6 H 4 CH 2 , X = I; 4b, R = EtO 2 CCH 2 , X = I) in 67-97% yields. Further treatment of complexes 2a,b-4a,b with an equimolar mononuclear Fe complex (dppv)(CO) 2 Fe(pdt) and NaBF 4 resulted in formation of the targeted model complexes [RN(PPh 2 ) 2 Ni(μ-pdt)(μ-X)Fe(CO)(dppv)](BF 4 ) (5a, R = p-MeC 6 H 4 CH 2 , X = Cl; 5b, R = EtO 2 CCH 2 , X = Cl; 6a, R = p-MeC 6 H 4 CH 2 , X = Br; 6b, R = EtO 2 CCH 2 , X = Br; 7a, R = p-MeC 6 H 4 CH 2 , X = I; 7b, R = EtO 2 CCH 2 , X = I) in 60-96% yields. All the new complexes 3a,b-4a,b and 5a,b-7a,b have been characterized by elemental analysis and spectroscopy, and particularly for some of them (3a,b/4a,b and 5b/6b) by X-ray crystallography. More interestingly, the electrochemical and electrocatalytic properties of such halogenido-bridged model complexes are first studied systematically and particularly they have been found to be pre-catalysts for proton reduction to H 2 under CV conditions.

Investigation of the Effect of Low Level Maritime Haze on DMSP VHR and LF Imagery.

DTIC Science & Technology

1980-09-09

LA S LO i-4 CNJ 0) r m~X LA3 crj (N > Co -i s- - -I CN r -~ 4J. 4-4 C) 4-) >1 Cl) 0H 9 -r-( Nl NV C 0 MN (1)0 r4 s-4 L 4-)4 Uv) Cu...be approximated as : 5-12 o 0 LA r40 oD (n rn N .4 .-4 0 C14.. LA Ln LA N- 0N 0C) LA 4 . l4-) r-. LA en C4 N . 049 0 1 E-4~ . (1 0 .t 0 ’p .r LA LA LA ...w CN C1 04 .00 C4.) r -4 O N~ ’. r - CA a ’.0 LA w m~ N1 Q4-1 Ř .4.4 Q) I- Q) in - r-4 O 4 1d𔃺 -4 0 0 4J *-0 0~

SEPARATION OF NEPTUNIUM FROM PLUTONIUM BY CHLORINATION AND SUBLIMATION

DOEpatents

Fried, S.M.

1958-11-18

A process is described for separating neptunium from plutonium. The method consists in chlorinating a mixture of the oxides of Np and Pu by contacting the mixture with carbon tetrachloride at about 500 icient laborato C. ln this manner the Np is converted to the tetrachlorlde and the Pu converted to the trichloride. Since NpCl/sub 4/ is more latile than PuCl/sub 3/, the separation ls effected by vaporing sad subsequently condenslng the NpCl/sub 4/.

NMR studies on Pt anti-cancer drug interactions with DNA and related compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reily, M.D.

Three metastable species have been identified in the reaction between cisPt(Me/sub 2/SO)/sub 2/Cl/sub 2/ and 7-methyl inosine (7Melno), 7-9-dimethyl hypoxanthine, cytidine (Cyd), 5-methyl cytidine (5-MeCyd), and a series of 2- and 4-substituted pyridines (Xpy) in Me/sub 2/SO. These were cis (I) and trans(Pt(Me/sub 2/SO)(L)Cl/sub 2/) (II), and cis(Pt(Me/sub 2/SO)/sub 2/(L)Cl)Cl(III), where L = N3 or N1 bound C or l derivatives, respectively. cis(Pt(Me/sub 2/SO)(L)/sub 2/Cl)Cl(IV) and l are stable products when r < 0.5(PtL) or r > 0.5, respectively. The /sup 195/Pt NMR spectra of I-IV were recorded for 24 different Xpy. For each of four complexes the dependence ofmore » chemical shift on ligand pK/sub a/ was linear for 4Xpy. When 2X was -C = OR (R = H, Me phenyl) downfield shifts of ca. 100 ppm from the 4Xpy pK/sub a/ line were observed.Large upfield shifts were observed when 2X was -NR/sub 2/, R = H or alkyl« less

Natronorubrum sediminis sp. nov., an archaeon isolated from a saline lake.

PubMed

Gutiérrez, M C; Castillo, A M; Corral, P; Minegishi, H; Ventosa, A

2010-08-01

Two novel haloalkaliphilic archaea, strains CG-6T and CG-4, were isolated from sediment of the hypersaline Lake Chagannor in Inner Mongolia, China. Cells of the two strains were pleomorphic, non-motile and strictly aerobic. They required at least 2.5 M NaCl for growth, with optimum growth at 3.4 M NaCl. They grew at pH 8.0-11.0, with optimum growth at pH 9.0. Hypotonic treatment with less than 1.5 M NaCl caused cell lysis. The two strains had similar polar lipid compositions, possessing C20C20 and C20C25 derivatives of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. No glycolipids were detected. Comparison of 16S rRNA gene sequences and morphological features placed them in the genus Natronorubrum. 16S rRNA gene sequence similarities to strains of recognized species of the genus Natronorubrum were 96.2-93.8%. Detailed phenotypic characterization and DNA-DNA hybridization studies revealed that the two strains belong to a novel species in the genus Natronorubrum, for which the name Natronorubrum sediminis sp. nov. is proposed; the type strain is CG-6T (=CECT 7487T =CGMCC 1.8981T =JCM 15982T).

Thermophysical Characterization of MgCl2·6H2O, Xylitol and Erythritol as Phase Change Materials (PCM) for Latent Heat Thermal Energy Storage (LHTES)

PubMed Central

Höhlein, Stephan; König-Haagen, Andreas; Brüggemann, Dieter

2017-01-01

The application range of existing real scale mobile thermal storage units with phase change materials (PCM) is restricted by the low phase change temperature of 58 ∘C for sodium acetate trihydrate, which is a commonly used storage material. Therefore, only low temperature heat sinks like swimming pools or greenhouses can be supplied. With increasing phase change temperatures, more applications like domestic heating or industrial process heat could be operated. The aim of this study is to find alternative PCM with phase change temperatures between 90 and 150 ∘C. Temperature dependent thermophysical properties like phase change temperatures and enthalpies, densities and thermal diffusivities are measured for the technical grade purity materials xylitol (C5H12O5), erythritol (C4H10O4) and magnesiumchloride hexahydrate (MCHH, MgCl2·6H2O). The sugar alcohols xylitol and erythritol indicate a large supercooling and different melting regimes. The salt hydrate MgCl2·6H2O seems to be a suitable candidate for practical applications. It has a melting temperature of 115.1 ± 0.1 ∘C and a phase change enthalpy of 166.9 ± 1.2 J/g with only 2.8 K supercooling at sample sizes of 100 g. The PCM is stable over 500 repeated melting and solidification cycles at differential scanning calorimeter (DSC) scale with only small changes of the melting enthalpy and temperature. PMID:28772806

Cobalt(II) chloride adducts with acetonitrile, propan-2-ol and tetrahydrofuran: considerations on nuclearity, reactivity and synthetic applications.

PubMed

Stinghen, Danilo; Rüdiger, André Luis; Giese, Siddhartha O K; Nunes, Giovana G; Soares, Jaísa F; Hughes, David L

2017-02-01

High-spin cobalt(II) complexes are considered useful building blocks for the synthesis of single-molecule magnets (SMM) because of their intrinsic magnetic anisotropy. In this work, three new cobalt(II) chloride adducts with labile ligands have been synthesized from anhydrous CoCl 2 , to be subsequently employed as starting materials for heterobimetallic compounds. The products were characterized by elemental, spectroscopic (EPR and FT-IR) and single-crystal X-ray diffraction analyses. trans-Tetrakis(acetonitrile-κN)bis(tetrahydrofuran-κO)cobalt(II) bis[(acetonitrile-κN)trichloridocobaltate(II)], [Co(C 2 H 3 N) 4 (C 4 H 8 O) 2 ][CoCl 3 (C 2 H 3 N)] 2 , (1), comprises mononuclear ions and contains both acetonitrile and tetrahydrofuran (thf) ligands, The coordination polymer catena-poly[[tetrakis(propan-2-ol-κO)cobalt(II)]-μ-chlorido-[dichloridocobalt(II)]-μ-chlorido], [Co 2 Cl 4 (C 3 H 8 O) 4 ], (2'), was prepared by direct reaction between anhydrous CoCl 2 and propan-2-ol in an attempt to rationalize the formation of the CoCl 2 -alcohol adduct (2), probably CoCl 2 (HO i Pr) m . The binuclear complex di-μ-chlorido-1:2κ 4 Cl:Cl-dichlorido-2κ 2 Cl-tetrakis(tetrahydrofuran-1κO)dicobalt(II), [Co 2 Cl 4 (C 4 H 8 O) 4 ], (3), was obtained from (2) after recrystallization from tetrahydrofuran. All three products present cobalt(II) centres in both octahedral and tetrahedral environments, the former usually less distorted than the latter, regardless of the nature of the neutral ligand. Product (2') is stabilized by an intramolecular hydrogen-bond network that appears to favour a trans arrangement of the chloride ligands in the octahedral moiety; this differs from the cis disposition found in (3). The expected easy displacement of the bound solvent molecules from the metal coordination sphere makes the three compounds good candidates for suitable starting materials in a number of synthetic applications.

Synthesis, structure and physicochemical characterization of the hybrid material [C6H16N2O]2 SnCl6·2Cl·2H2O

NASA Astrophysics Data System (ADS)

Belhaj Salah, S.; Pereira da Silva, P. S.; Lefebvre, F.; Ben Nasr, C.; Ammar, S.; Mrad, M. L.

2017-04-01

The current study reports the chemical preparation, crystal structure, Hirshfeld surface analysis and spectroscopic characterization of the novel compound [C6H16N2O]2SnCl6·2Cl·2H2O. This compound crystallizes in the triclinic system (space group P - 1, Z = 1) with the following unit cell dimensions: a = 7.9764(9), b = 8.2703(9), c = 12.1103(14)Å, α = 84.469(6), β = 75.679(6), and γ = 64.066(5)°. The structure was solved using 3093 independent reflections down to R = 0.020. The atomic arrangement shows alternation of organic and inorganic entities. The cohesion between these entities is ensured by Nsbnd H…Cl and Osbnd H…Cl hydrogen bonds that build a three-dimensional network. The 3D Hirshfeld surfaces and the associated 2D fingerprint plots were investigated for intermolecular interactions. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the IR and NMR bands. X-ray powder, XPS and UV spectrum have been carried out. The DSC profile shows that the title material exhibits dehydration at 339 K.

Development and validation of a general approach to predict and quantify the synergism of anti-cancer drugs using experimental design and artificial neural networks.

PubMed

Pivetta, Tiziana; Isaia, Francesco; Trudu, Federica; Pani, Alessandra; Manca, Matteo; Perra, Daniela; Amato, Filippo; Havel, Josef

2013-10-15

The combination of two or more drugs using multidrug mixtures is a trend in the treatment of cancer. The goal is to search for a synergistic effect and thereby reduce the required dose and inhibit the development of resistance. An advanced model-free approach for data exploration and analysis, based on artificial neural networks (ANN) and experimental design is proposed to predict and quantify the synergism of drugs. The proposed method non-linearly correlates the concentrations of drugs with the cytotoxicity of the mixture, providing the possibility of choosing the optimal drug combination that gives the maximum synergism. The use of ANN allows for the prediction of the cytotoxicity of each combination of drugs in the chosen concentration interval. The method was validated by preparing and experimentally testing the combinations with the predicted highest synergistic effect. In all cases, the data predicted by the network were experimentally confirmed. The method was applied to several binary mixtures of cisplatin and [Cu(1,10-orthophenanthroline)2(H2O)](ClO4)2, Cu(1,10-orthophenanthroline)(H2O)2(ClO4)2 or [Cu(1,10-orthophenanthroline)2(imidazolidine-2-thione)](ClO4)2. The cytotoxicity of the two drugs, alone and in combination, was determined against human acute T-lymphoblastic leukemia cells (CCRF-CEM). For all systems, a synergistic effect was found for selected combinations. © 2013 Elsevier B.V. All rights reserved.

Easy access to silicon(0) and silicon(II) compounds.

PubMed

Mondal, Kartik Chandra; Samuel, Prinson P; Tretiakov, Mykyta; Singh, Amit Pratap; Roesky, Herbert W; Stückl, A Claudia; Niepötter, Benedikt; Carl, Elena; Wolf, Hilke; Herbst-Irmer, Regine; Stalke, Dietmar

2013-04-15

Two different synthetic methodologies of silicon dihalide bridged biradicals of the general formula (L(n)•)2SiX2 (n = 1, 2) have been developed. First, the metathesis reaction between NHC:SiX2 and L(n): (L(n): = cyclic akyl(amino) carbene in a 1:3 molar ratio leads to the products 2 (n = 1, X = Cl), 4 (n = 2, X = Cl), 6 (n = 1, X = Br), and 7 (n = 2, X = Br). These reactions also produce coupled NHCs (3, 5) under C-C bond formation. The formation of the coupled NHCs (L(m) = cyclic alkyl(amino) carbene substituted N-heterocyclic carbene; m = 3, n = 1 (3) and m = 4, n =2 (5)) is faster during the metathesis reaction between NHC:SiBr2 and L(n): when compared with that of NHC:SiCl2. Second, the reaction of L(1):SiCl4 (8) (L(1): =:C(CH2)(CMe2)2N-2,6-iPr2C6H3) with a non-nucleophilic base LiN(iPr)2 in a 1:1 molar ratio shows an unprecedented methodology for the synthesis of the biradical (L(1)•)2SiCl2 (2). The blue blocks of silicon dichloride bridged biradicals (2, 4) are stable for more than six months under an inert atmosphere and in air for one week. Compounds 2 and 4 melt in the temperature range of 185 to 195 °C. The dibromide (6, 7) analogue is more prone to decomposition in the solution but comparatively more stable in the solid state than in the solution. Decomposition of the products has been observed in the UV-vis spectra. Moreover, compounds 2 and 4 were further converted to stable singlet biradicaloid dicarbene-coordinated (L(n):)2Si(0) (n = 1 (9), 2 (10)) under KC8 reduction. Compounds 2 and 4 were also reduced to dehalogenated products 9 and 10, respectively when treated with RLi (R = Ph, Me, tBu). Cyclic voltametry measurements show that 10 can irreversibly undergo both one electron oxidation and reduction.

High-pressure single-crystal synchrotron X-ray diffraction of kainite (KMg(SO4) Cl 3H2O)

NASA Astrophysics Data System (ADS)

Nazzareni, S.; Comodi, P.; Hanfland, M.

2018-03-01

Kainite (KMg(SO4) Cl 3H2O) is a "mixed-salt" sulfate from the group of evaporitic minerals more soluble than Ca-sulfate hydrate and NaCl. The compressibility and structural modifications of monoclinic (sp. gr. C2/m) kainite up to a pressure of 14 GPa were studied by high-pressure single-crystal synchrotron X-ray diffraction. Kainite remains stable over the investigated pressure range and no phase transition was recognised. The bulk modulus is K 0 = 31.6 (1) GPa, with K' fixed to 4, as obtained by fitting the P-volume data with a second-order Birch-Murnaghan EoS (BM2); instead of using a BM3 EoS, we obtained K 0 = 32.2(5) GPa, K' =3.8 (1). The linear moduli calculated for the lattice parameters fitting the data with a BM3 EoS are for a-axis M 0a = 117(4) GPa, Mpa = 11(1), for b-axis M 0b = 113(2) GPa, Mpc = 8.6(5), and c-axis M 0c = 68.2(3) GPa, Mpc = 14(1). Structure refinements showed a strong compression of the K polyhedra and in particular K(1) and K(3) polyhedra have similar polyhedral bulk moduli: K 0K(1) = 20.8(7) GPa, K'=4.8(3); K 0K(2) = 29(1) GPa, K'=8.1(6); K 0K(3) = 26(1) GPa, K'=4.2(4). The most compressible bond distances are K(1)-Cl(2) with a shortening of about 13%, K(1)-Cl(1) with a shortening of about 10%, K(3)-Ow(6) and K(3)-O8(B) both with a shortening of 9%. S-tetrahedra are almost incompressible and Mg-octahedra bulk moduli are K 0Mg(2) = 102(4) GPa, and K 0Mg(4) = 72(1) GPa, K 0Mg(1) = 41(4) GPa K'= 8.9(1.7), and K 0Mg(3) = 65(5) GPa K'= 10(2). The strain tensor analysis indicates that the most compressible direction of the kainite monoclinic structure is oriented 29.7(2)° from the c-axis in the (0 1 0) plane. The shortening of the K(1)-K(2) distance (from 4.219(4) Å at ambient P to 3.521(7) Å at 11.9 GPa) and the different compressibilities of the octahedra/tetrahedra may explain why the stiffer direction of kainite is in the a-c plane approximatively along the direction where K(1)-K(2) and Mg(4)-Mg(3)-Mg(4) polyhedra align. This may explain the anisotropic compressional behaviour of the crystallographic axes, where c is more compressible (by tetrahedral tilting mechanism) than a and b, where cation-cation repulsion and a more rigid configuration make these directions stiffer. Following the structure modification increasing pressure a new sets of hydrogens bonds could form as oxygens and chlorine atoms get at less than 3 Å distance from the Ow.

Cationic and Neutral Cp*M(NO)(κ2-Ph2PCH2CH2PPh2) Complexes of Molybdenum and Tungsten: Lewis-Acid-Induced Intramolecular C-H Activation.

PubMed

Handford, Rex C; Wakeham, Russell J; Patrick, Brian O; Legzdins, Peter

2017-03-20

Treatment of CH 2 Cl 2 solutions of Cp*M(NO)Cl 2 (Cp* = η 5 -C 5 (CH 3 ) 5 ; M = Mo, W) first with 2 equiv of AgSbF 6 in the presence of PhCN and then with 1 equiv of Ph 2 PCH 2 CH 2 PPh 2 affords the yellow-orange salts [Cp*M(NO)(PhCN)(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 )](SbF 6 ) 2 in good yields (M = Mo, W). Reduction of [Cp*M(NO)(PhCN)(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 )](SbF 6 ) 2 with 2 equiv of Cp 2 Co in C 6 H 6 at 80 °C produces the corresponding 18e neutral compounds, Cp*M(NO)(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 ) which have been isolated as analytically pure orange-red solids. The addition of 1 equiv of the Lewis acid, Sc(OTf) 3 , to solutions of Cp*M(NO)(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 ) at room temperature results in the immediate formation of thermally stable Cp*M(NO→Sc(OTf) 3 )(H)(κ 3 -(C 6 H 4 )PhPCH 2 CH 2 PPh 2 ) complexes in which one of the phenyl substituents of the Ph 2 PCH 2 CH 2 PPh 2 ligands has undergone intramolecular orthometalation. In a similar manner, addition of BF 3 produces the analogous Cp*M(NO→BF 3 )(H)(κ 3 -(C 6 H 4 )PhPCH 2 CH 2 PPh 2 ) complexes. In contrast, B(C 6 F 5 ) 3 forms the 1:1 Lewis acid-base adducts, Cp*M(NO→B(C 6 F 5 ) 3 )(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 ) in CH 2 Cl 2 at room temperature. Upon warming to 80 °C, Cp*Mo(NO→B(C 6 F 5 ) 3 )(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 ) converts cleanly to the orthometalated product Cp*Mo(NO→B(C 6 F 5 ) 3 )(H)(κ 3 -(C 6 H 4 )PhPCH 2 CH 2 PPh 2 ), but Cp*W(NO→B(C 6 F 5 ) 3 )(κ 2 -Ph 2 PCH 2 CH 2 PPh 2 ) generates a mixture of products whose identities remain to be ascertained. Attempts to extend this chemistry to include related Ph 2 PCH 2 PPh 2 compounds have had only limited success. All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.

Effect of ammonium sulfate, ammonium chloride and root-zone acidity on inorganic ion content of tobacco

NASA Technical Reports Server (NTRS)

Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

1990-01-01

Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH4)2SO4 or NH4Cl at root-zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH4+ source or root-zone pH. Plants supplied with NH4Cl accumulated up to 1.2 mM Cl g DW-1, but accumulated 37% less inorganic H2PO4- and 47% less SO4(2-) than plants supplied with (NH4)2SO4. The large Cl- accumulation resulted in NH4Cl- supplied plants having a 31% higher inorganic anion (NO3-, H2, PO4-, SO4(2-), and Cl-) charge. This higher inorganic anion charge in the NH4Cl-supplied plants was balanced by a similar increase in K+ charge. Plants supplied with NH4Cl accumulated greater concentrations of Cl- in leaves (up to 5.1% of DW) than plants supplied with (NH4)2SO4 (less than -% DW). Despite the high Cl- concentration of leaves in NH4Cl supplied plants, these plants showed no symptoms of Cl- toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl- concentration in tissue and NH4+ nutrition. The increase in root-zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.

Optimization, purification and characterization of novel thermostable, haloalkaline, solvent stable protease from Bacillus halodurans CAS6 using marine shellfish wastes: a potential additive for detergent and antioxidant synthesis.

PubMed

Annamalai, Neelamegam; Rajeswari, Mayavan Veeramuthu; Thavasi, Rengathavasi; Vijayalakshmi, Shanmugam; Balasubramanian, Thangavel

2013-07-01

A protease producing marine bacterium, Bacillus halodurans CAS6 isolated from marine sediments, was found to produce higher enzyme by utilizing shrimp shell powder. Optimum culture conditions for protease production were 50 °C, pH 9.0, 30 % NaCl and 1 % shrimp shell powder (SSP) and the protease purified with a specific activity of 509.84 U/mg. The enzyme retained 100 % of its original activity even at 70 °C, pH 10.0 and 30 % NaCl for 1 h. The purified protease exhibited higher stability when treated with ionic, non-ionic (72-94 %) and commercial detergents (76-88 %), and organic solvents (88-126 %). Significant blood stain removal activity was found with the enzyme in washing experiments. The culture supernatant supplemented with 1 % SSP showed 93.67 ± 2.52 % scavenging activity and FT-IR analysis of the reaction mixture confirmed the presence of antioxidants such as cyclohexane and cyclic depsipeptide with aliphatic amino groups. These remarkable qualities found with this enzyme produced by Bacillus halodurans CAS6 could make this as an ideal candidate to develop the industrial process for bioconversion of marine wastes and antioxidant synthesis.

High Coulombic efficiency aluminum-ion battery using an AlCl3-urea ionic liquid analog electrolyte

PubMed Central

Angell, Michael; Pan, Chun-Jern; Rong, Youmin; Yuan, Chunze; Lin, Meng-Chang; Hwang, Bing-Joe; Dai, Hongjie

2017-01-01

In recent years, impressive advances in harvesting renewable energy have led to a pressing demand for the complimentary energy storage technology. Here, a high Coulombic efficiency (∼99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analog electrolyte made from a mixture of AlCl3 and urea in a 1.3:1 molar ratio. The battery displays discharge voltage plateaus around 1.9 and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ∼73 mAh g−1 at a current density of 100 mA g−1 (∼1.4 C). High Coulombic efficiency over a range of charge–discharge rates and stability over ∼150–200 cycles was easily demonstrated. In situ Raman spectroscopy clearly showed chloroaluminate anion intercalation/deintercalation of graphite (positive electrode) during charge–discharge and suggested the formation of a stage 2 graphite intercalation compound when fully charged. Raman spectroscopy and NMR suggested the existence of AlCl4−, Al2Cl7− anions and [AlCl2·(urea)n]+ cations in the AlCl3/urea electrolyte when an excess of AlCl3 was present. Aluminum deposition therefore proceeded through two pathways, one involving Al2Cl7− anions and the other involving [AlCl2·(urea)n]+ cations. This battery is a promising prospect for a future high-performance, low-cost energy storage device. PMID:28096353

4-Alkynylphenylsilatranes: Insecticidal activity, mammalian toxicity, and mode of action

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horsham, M.A.; Palmer, C.J.; Cole, L.M.

1990-08-01

4-Ethynyl- and 4-(prop-1-ynyl)phenylsilatranes (N(CH{sub 2}CH{sub 2}O){sub 3}SiR, R = C{sub 6}H{sub 4}-4-C{triple bond}CH or C{sub 6}H{sub 4}-4-C{triple bond}CCH{sub 3}) are highly toxic to houseflies (pretreated with piperonyl butoxide) and milkweed bugs (topical LD{sub 50}s 3-14 {mu}g/g) and to mice (intraperitoneal LD{sub 50}s 0.4-0.9 mg/kg), and they are moderately potent inhibitors of the ({sup 35}S)-tert-butylbicyclophosphorothionate or TBPS binding site (GABA-gated chloride channel) of mouse brain membranes. Scatchard analysis indicates noncompetitive interaction of 4-ethynylphenylsilatrane with the TBPS binding site. Phenylsilatrane analogues with 4-substituents of H, CH{sub 3}, Cl, Br, and C{triple bond}CSi(CH{sub 3}){sub 3} are highly toxic to mice but have littlemore » or no activity in the insect and receptor assays. Radioligand binding studies with (4-{sup 3}H)phenylsilatrane failed to reveal a specific binding site in mouse brain. Silatranes with R = H, CH{sub 3}, CH{sub 2}Cl, CH{double bond}CH{sub 2}, OCH{sub 2}CH{sub 3}, and C{sub 6}H{sub 4}-4-CH{sub 2}CH{sub 3} are of little or no activity in the insect and mouse toxicity and TBPS binding site assays as are the trithia and monocyclic analogues of phenylsilatrane. 4-Alkynylphenylsilatranes are new probes to examine the GABA receptor-ionophore complex of insects and mammals.« less

Modeling the effects of temperature, sodium chloride, and green tea and their interactions on the thermal inactivation of Listeria monocytogenes in turkey.

PubMed

Juneja, Vijay K; Garcia-Dávila, Jimena; Lopez-Romero, Julio Cesar; Pena-Ramos, Etna Aida; Camou, Juan Pedro; Valenzuela-Melendres, Martin

2014-10-01

The interactive effects of heating temperature (55 to 65°C), sodium chloride (NaCl; 0 to 2%), and green tea 60% polyphenol extract (GTPE; 0 to 3%) on the heat resistance of a five-strain mixture of Listeria monocytogenes in ground turkey were determined. Thermal death times were quantified in bags that were submerged in a circulating water bath set at 55, 57, 60, 63, and 65°C. The recovery medium was tryptic soy agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. D-values were analyzed by second-order response surface regression for temperature, NaCl, and GTPE. The data indicated that all three factors interacted to affect the inactivation of the pathogen. The D-values for turkey with no NaCl or GTPE at 55, 57, 60, 63, and 65°C were 36.3, 20.8, 13.2, 4.1, and 2.9 min, respectively. Although NaCl exhibited a concentration-dependent protective effect against heat lethality on L. monocytogenes in turkey, addition of GTPE rendered the pathogen more sensitive to the lethal effect of heat. GTPE levels up to 1.5% interacted with NaCl and reduced the protective effect of NaCl on heat resistance of the pathogen. Food processors can use the predictive model to design an appropriate heat treatment that would inactivate L. monocytogenes in cooked turkey products without adversely affecting the quality of the product.

Direct measurement of the Bose-Einstein condensation universality class in NiCl2-4SC(NH2)2 at ultralow temperatures.

PubMed

Yin, L; Xia, J S; Zapf, V S; Sullivan, N S; Paduan-Filho, A

2008-10-31

In this work, we demonstrate field-induced Bose-Einstein condensation (BEC) in the organic compound NiCl2-4SC(NH2)_{2} using ac susceptibility measurements down to 1 mK. The Ni S=1 spins exhibit 3D XY antiferromagnetism between a lower critical field H_{c1} approximately 2 T and a upper critical field H_{c2} approximately 12 T. The results show a power-law temperature dependence of the phase transition line H_{c1}(T)-H_{c1}(0)=aT;{alpha} with alpha=1.47+/-0.10 and H_{c1}(0)=2.053 T, consistent with the 3D BEC universality class. Near H_{c2}, a kink was found in the phase boundary at approximately 150 mK.

pH and external Ca(2+) regulation of a small conductance Cl(-) channel in kidney distal tubule.

PubMed

Sauvé, R; Cai, S; Garneau, L; Klein, H; Parent, L

2000-12-20

A single channel characterization of the Cl(-) channels in distal nephron was undertaken using vesicles prepared from plasma membranes of isolated rabbit distal tubules. The presence in this vesicle preparation of ClC-K type Cl(-) channels was first established by immunodetection using an antibody raised against ClC-K isoforms. A ClC-K1 based functional characterization was next performed by investigating the pH and external Ca(2+) regulation of a small conductance Cl(-) channel which we identified previously by channel incorporation experiments. Acidification of the cis (external) solution from pH 7.4 to 6.5 led to a dose-dependent inhibition of the channel open probability P(O). Similarly, changing the trans pH from 7.4 to 6.8 resulted in a 4-fold decrease of the channel P(O) with no effect on the channel conductance. Channel activity also appeared to be regulated by cis (external) Ca(2+) concentration, with a dose-dependent increase in channel activity as a function of the cis Ca(2+) concentration. It is concluded on the basis of these results that the small conductance Cl(-) channel present in rabbit distal tubules is functionally equivalent to the ClC-K1 channel in the rat. In addition, the present work constitutes the first single channel evidence for a chloride channel regulated by external Ca(2+).

Reaction of BH4- with [Mo2Cp2(mu-SMe)n] species to give tetrahydroborato, hydrido or dimetallaborane compounds: control of product by ancillary ligands.

PubMed

Cabon, Nolwenn; Petillon, Francois Y; Schollhammer, Philippe; Talarmin, Jean; Muir, Kenneth W

2004-09-07

The reaction of mono- or dichloro-dimolybdenum(III) complexes [Mo2Cp2(mu-SMe)2(mu-Cl)(mu-Y)] (Cp=eta5-C5H5; 1, Y=SMe; 2, Y=PPh2; 3, Y=Cl) with NaBH4 at room temperature gave in high yields tetrahydroborato (8), hydrido (9) or metallaborane (12) complexes depending on the ancillary ligands. The correct formulation of derivatives and has been unambigously determined by X-ray diffraction methods. That of the hydrido compound 9 has been established in solution by NMR analysis and confirmed by an X-ray study of the mu-azavinylidene derivative [Mo2Cp2(mu-SMe)2(mu-PPh2)(mu-N=CHMe)] (10) obtained from the insertion of acetonitrile into the Mo-H bond of 9. Reaction of NaBH4 with nitrile derivatives, [Mo2Cp2(mu-SMe)4-n(CH3CN)2n]n+(5, n=1; 6 n=2), afforded the tetrahydroborato compound 8, together with a mu-azavinylidene species [Mo2Cp2(mu-SMe)3(mu-N=CHMe)](14), when n=1, and the metallaborane complex 12, together with a mixed borohydrato-azavinylidene derivative [Mo2Cp2(mu-SMe)2(mu-BH4)(mu-N=CHMe)] (13), when n=2. The molecular structures of these complexes have been confirmed by X-ray analysis. Preparations of some of the starting complexes (3 and 4) are also described, as are the molecular structures of the precursors [Mo2Cp2(mu-SMe)2(mu-X)(mu-Y)] (1, X/Y=Cl/SMe; 2, X/Y=Cl/PPh2; 4, X/Y=SMe/PPh2).

(2E)-1-(2,6-Dichloro-3-fluoro-phen-yl)-3-phenyl-prop-2-en-1-one.

PubMed

Praveen, Aletti S; Yathirajan, Hemmige S; Narayana, Badiadka; Gerber, Thomas; Hosten, Eric; Betz, Richard

2012-04-01

In the title compound, C(15)H(9)Cl(2)FO, the F atom shows positional disorder over two positions, with site-occupancy factors of 0.747 (4) and 0.253 (4). The dihedral angle between the rings is 86.37 (10)°. In the crystal, C-H⋯O contacts connect the mol-ecules into chains along the c axis. The shortest inter-centroid distance between two aromatic systems is 3.6686 (12) Å and is apparent between the halogenated rings.

Mitochondrial dysfunction in H9c2 cells during ischemia and amelioration with Tribulus terrestris L.

PubMed

Reshma, P L; Sainu, Neethu S; Mathew, Anil K; Raghu, K G

2016-05-01

The present study investigates the protective effect of partially characterized Tribulus terrestris L. fruit methanol extract against mitochondrial dysfunction in cell based (H9c2) myocardial ischemia model. To induce ischemia, the cells were maintained in an ischemic buffer (composition in mM -137 NaCl, 12 KCl, 0.5 MgCl2, 0.9 CaCl2, 20 HEPES, 20 2-deoxy-d-glucose, pH-6.2) at 37°C with 0.1% O2, 5% CO2, and 95% N2 in a hypoxia incubator for 1h. Cells were pretreated with various concentrations of T. terrestris L. fruit methanol extract (10 and 25μg/ml) and Cyclosporin A (1μM) for 24h prior to the induction of ischemia. Different parameters like lactate dehydrogenase release, total antioxidant capacity, glutathione content and antioxidant enzymes were investigated. Studies were conducted on mitochondria by analyzing alterations in mitochondrial membrane potential, integrity, and dynamics (fission and fusion proteins - Mfn1, Mfn2, OPA1, Drp1 and Fis1). Various biochemical processes in mitochondria like activity of electron transport chain (ETC) complexes, oxygen consumption and ATP production was measured. Ischemia for 1h caused a significant (p≤0.05) increase in LDH leakage, decrease in antioxidant activity and caused mitochondrial dysfunction. T. terrestris L. fruit methanol extract pretreatment was found effective in safeguarding mitochondria via its antioxidant potential, mediated through various bioactives. HPLC of T. terrestris L. fruit methanol extract revealed the presence of ferulic acid, phloridzin and diosgenin. T. terrestris L. fruit ameliorate ischemic insult in H9c2 cells by safeguarding mitochondrial function. This validates the use of T. terrestris L. against heart disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Group 13 β-ketoiminate compounds: gallium hydride derivatives as molecular precursors to thin films of Ga2O3.

PubMed

Pugh, David; Marchand, Peter; Parkin, Ivan P; Carmalt, Claire J

2012-06-04

Bis(β-ketoimine) ligands, [R{N(H)C(Me)-CHC(Me)═O}(2)] (L(1)H(2), R = (CH(2))(2); L(2)H(2), R = (CH(2))(3)), linked by ethylene (L(1)) and propylene (L(2)) bridges have been used to form aluminum, gallium, and indium chloride complexes [Al(L(1))Cl] (3), [Ga(L(n))Cl] (4, n = 1; 6, n = 2) and [In(L(n))Cl] (5, n = 1; 7, n = 2). Ligand L(1) has also been used to form a gallium hydride derivative [Ga(L(1))H] (8), but indium analogues could not be made. β-ketoimine ligands, [Me(2)N(CH(2))(3)N(H)C(R')-CHC(R')═O] (L(3)H, R' = Me; L(4)H, R' = Ph), with a donor-functionalized Lewis base have also been synthesized and used to form gallium and indium alkyl complexes, [Ga(L(3))Me(2)] (9) and [In(L(3))Me(2)] (10), which were isolated as oils. The related gallium hydride complexes, [Ga(L(n))H(2)] (11, n = 3; 12, n = 4), were also prepared, but again no indium hydride species could be made. The complexes were characterized mainly by NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction. The β-ketoiminate gallium hydride compounds (8 and 11) have been used as single-source precursors for the deposition of Ga(2)O(3) by aerosol-assisted (AA)CVD with toluene as the solvent. The quality of the films varied according to the precursor used, with the complex [Ga(L(1))H] (8) giving by far the best quality films. Although the films were amorphous as deposited, they could be annealed at 1000 °C to form crystalline Ga(2)O(3). The films were analyzed by powder XRD, SEM, and EDX.

Synthesis, antifungal activity and docking study of 2-amino-4H-benzochromene-3-carbonitrile derivatives

NASA Astrophysics Data System (ADS)

Mirjalili, BiBi Fatemeh; Zamani, Leila; Zomorodian, Kamiar; Khabnadideh, Soghra; Haghighijoo, Zahra; Malakotikhah, Zahra; Ayatollahi Mousavi, Seyyed Amin; Khojasteh, Shaghayegh

2016-07-01

Pathogenic fungi are associated with diseases ranging from simple dermatosis to life-threatening infections, particularly in immunocompromised patients. During the past two decades, resistance to established antifungal drugs has increased dramatically and has made it crucial to identify novel antimicrobial compounds. Here, we selected 12 new compounds of 2-amino-4H-benzochromene-3-carbonitrile drivetives (C1-C12) for synthesis by using nano-TiCl4.SiO2 as efficient and green catalyst, then nine of synthetic compounds were evaluated against different species of fungi, positive gram and negative gram of bacteria. Standard and clinical strains of antibiotics sensitive and resistant fungi and bacteria were cultured in appropriate media. Biological activity of the 2-amino-4H-benzochromene-3-carbonitrile derivatives against fungi and bacteries were estimated by the broth micro-dilution method as recommended by clinical and laboratory standard institute (CLSI). In addition minimal fangicidal and bactericial concenteration of the compounds were also determined. Considering our results showed that compound 2-amino-4-(4-methyl benzoate)-4H-benzo[f]chromen-3-carbonitrile (C9) had the most antifungal activity against Aspergillus clavatus, Candida glabarata, Candida dubliniensis, Candida albicans and Candida tropicalis at concentrations ranging from 8 to ≤128 μg/mL. Also compounds 2-amino-4-(3,4-dimethoxyphenyl)-4H-benzo[f]chromen-3-carbonitrile (C4) and 2-amino-4-(4-isopropylphenyl)-4H-benzo[f]chromen-3-carbonitrile (C3) had significant inhibitory activities against Epidermophyton floccosum following 2-amino-4-(4-methylbenzoate)-4H-benzo[f]chromen-3-carbonitrile (C9), respectively. Docking simulation was performed to insert compounds C3, C4 and C9 in to CYP51 active site to determine the probable binding model.

Catalytic Hydroxylation of Benzene to Phenol by Dioxygen with an NADH Analogue.

PubMed

Hirose, Kensaku; Ohkubo, Kei; Fukuzumi, Shunichi

2016-08-26

Hydroxylation of benzene by molecular oxygen (O2 ) occurs efficiently with 10-methyl-9,10-dihydroacridine (AcrH2 ) as an NADH analogue in the presence of a catalytic amount of Fe(ClO4 )3 or Fe(ClO4 )2 with excess trifluoroacetic acid in a solvent mixture of benzene and acetonitrile (1:1 v/v) to produce phenol, 10-methylacridinium ion and hydrogen peroxide (H2 O2 ) at 298 K. The catalytic oxidation of benzene by O2 with AcrH2 in the presence of a catalytic amount of Fe(ClO4 )3 is started by the formation of H2 O2 from AcrH2 , O2 , and H(+) . Hydroperoxyl radical (HO2 (.) ) is produced from H2 O2 with the redox pair of Fe(3+) /Fe(2+) by a Fenton type reaction. The rate-determining step in the initiation is the proton-coupled electron transfer from Fe(2+) to H2 O2 to produce HO(.) and H2 O. HO(.) abstracts hydrogen rapidly from H2 O2 to produce HO2 (.) and H2 O. The Fe(3+) produced was reduced back to Fe(2+) by H2 O2 . HO2 (.) reacts with benzene to produce the radical adduct, which abstracts hydrogen from AcrH2 to give the corresponding hydroperoxide, accompanied by generation of acridinyl radical (AcrH(.) ) to constitute the radical chain reaction. Hydroperoxyl radical (HO2 (.) ), which was detected by using the spin trap method with EPR analysis, acts as a chain carrier for the two radical chain pathways: one is the benzene hydroxylation with O2 and the second is oxidation of an NADH analogue with O2 to produce H2 O2 . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of shift in growth temperature on tolerance of psychrotrophic and mesophilic strains of Bacillus cereus to heat and sodium chloride.

PubMed

Mahakarnchanakul, W; Beuchat, L R

1999-01-01

A shift in growth temperature of a psychrotrophic (F3802A/84) strain and a mesophilic strain (B4ac-1) of Bacillus cereus grown at 30 degrees C for 10 h, then at 37 degrees C or 40 degrees C for 14 h, enhanced thermotolerance. Sodium chloride, at concentrations of 2.0 and 4.0% in brain heart infusion (BHI) broth, had no effect on thermotolerance of strain B4ac-1 heated at 50 degrees C, whereas the same concentrations of NaCl caused a decrease in thermotolerance of strain F3802A/84 heated at 48 degrees C. A downshift in growth temperature from 30 degrees C to 10 degrees C followed by incubation for 3 to 9 days increased thermotolerance of strain F3802A/84 but not strain B4ac-1 heated in BHI broth containing 2.0 or 4.0% NaCl compared to thermotolerance in BHI broth containing 0.5% NaCl. Protein analysis using one-dimensional gel electrophoresis revealed an increase in proteins with molecular weights of 54, 50, 44, and 42 kDa in cells of strain F3802A/84 and 83 and 69 kDa in cells of strain B4ac-1 subjected to an upshift in growth temperature from 30 degrees C to 37 degrees C or 40 degrees C, respectively. A downshift in growth temperature from 30 degrees C to 10 degrees C resulted in substantial amounts of proteins with molecular weights of 63, 40, and 29 kDa produced by strain F3802A/84 and 63 kDa to be produced by strain B4ac-1. Proteins produced in response to upshift or downshift in growth temperature are suspected to play an important role in heat resistance of the psychrotrophic and mesophilic strains of B. cereus examined in this study. Changes in resistance to heat or refrigeration temperatures, as well as tolerance to NaCl, as affected by previous exposure of cells to temperature shifts may influence the ability of B. cereus to grow in minimally processed foods during distribution and storage.

Cis Effects in the Cobalt Corrins. 1. Crystal Structures of 10-Chloroaquacobalamin Perchlorate, 10-Chlorocyanocobalamin, and 10-Chloromethylcobalamin.

PubMed

Brown, Kenneth L.; Cheng, Shifa; Zou, Xiang; Zubkowski, Jeffrey D.; Valente, Edward J.; Knapton, Leanne; Marques, Helder M.

1997-08-13

The crystal structures of 10-chloroaquacobalamin perchlorate hydrate (10-Cl-H(2)OCbl.ClO(4)) (Mo Kalpha, 0.710 73 Å, monoclinic system, P2(1), a = 11.922(4) Å, b = 26.592(10) Å, c = 13.511(5) Å, beta = 93.05(3) degrees, 10 535 independent reflections, R(1) = 0.0426), 10-chlorocyanocobalamin-acetone hydrate (10-Cl-CNCbl) (Mo Kalpha, 0.710 73 Å, orthorhombic system, P2(1)2(1)2(1), a = 16.24(3) Å, b = 21.85(5) Å, c = 26.75(8) Å, 7699 independent reflections, R(1) = 0.0698), and 10-chloromethylcobalamin-acetone hydrate (10-Cl-MeCbl) (Mo Kalpha, 0.71073 Å, orthorhombic system, P2(1)2(1)2(1), a = 16.041(14) Å, b = 22.13(2) Å, c = 26.75(4) Å, 6792 independent reflections, R(1) = 0.0554), in which the C10 meso H is substituted by Cl, are reported. An unusual feature of the structures is disorder in the C ring, consistent with a two-site occupancy in which the major conformation has the C46 methyl group in the usual position, "upwardly" axial, and the C47 methyl group equatorial, while in the minor conformation both are pseudoequatorial, above and below the corrin ring. (13)C NMR chemical shifts of C46, C47, C12, and C13 suggest that the C ring disorder may persist in solution as a ring flip. Since molecular dynamics simulations fail to reveal any population of the minor conformation, the effect is likely to be electronic rather than steric. The axial bond lengths in 10-Cl-MeCbl are very similar to those in MeCbl (d(Co)(-)(C) = 1.979(7) vs 1.99(2); to 5,6-dimethylbenzimidazole, d(Co)(-)(NB3) = 2.200(7) vs 2.19(2)), but the bonds to the four equatorial N donors, d(Co)(-)(N(eq)), are on average 0.05 Å shorter. In 10-Cl-CNCbl, d(Co)(-)(C) and d(Co)(-)(NB3) are longer (by 0.10(2) and 0.03(1) Å, respectively) than the bond lengths observed in CNCbl itself, while conversely, the C-N bond length is shorter by 0.06(2) Å, but there is little difference in d(Co)(-)(N(eq)). The Co-O bond length to coordinated water in 10-Cl-H(2)OCbl(+) is very similar to that found in H(2)OCbl(+) itself, but the d(Co)(-)(NB3) bond is longer (1.967 vs1.925(2) Å), while the average d(Co)(-)(N(eq)) is very similar. The coordinated water molecule in 10-Cl-H(2)OCbl(+) is hydrogen bonded to the c side chain carbonyl oxygen, as in H(2)OCbl(+). NMR observations indicate that the H bond between coordinated H(2)O and the c side chain amide persists in solution. The equilibrium constant, K(Co), for coordination of bzm to Co(III) is smaller in 10-Cl-MeCbl and 10-Cl-CNCbl than in their C10-unsubstituted analogs (181 vs 452; 4.57 x 10(3) vs 3.35 x 10(5)), but could not be determined for 10-Cl-H(2)OCbl because hydrolysis of the phosphodiester is competitive with the establishment of the base-off equilibrium. Substitution of H by Cl at C10 causes the bands in the electronic spectrum of 10-Cl-XCbl complexes to move to lower energy, which is consistent with an increase in electron density in the corrin pi-conjugated system. This increased electron density is not due to greater electron donation from the axial ligand as bonds between these and the metal are either longer (not shorter) or unchanged, and it most probably arises from pi-donation to the corrin by Cl at C10. As the donor power of X increases (H(2)O < CN(-) < Me), the corrin ring becomes more flexible to deformation, and the number of bond lengths and bond angles that are significantly different in XCbl and 10-Cl-XCbl increases; importantly, the C10-Cl bond length, d(C10)(-)(Cl), increases as well. Thus, despite the fact that chlorine is an inductively electron withdrawing substituent, its resonance electron donation is the more important effect on electron distribution in the corrin ring. Mulliken charges obtained from semiempirical RHF-SCF MO calculations using the ZINDO/1 model on XCbl and their 10-Cl analogs at the crystal structure geometry are shown to correlate reasonably well with (13)C NMR shifts and may be used to determine the pattern of electron distribution in these complexes. Substitution by Cl at C10 causes an increase in charge density at Co when X = H(2)O and CN(-), while the charge density on the four equatorial N donors remains virtually unchanged, but a decrease when X = Me, while the charge density on the equatorial N donors also decreases. In response, d(Co)(-)(NB3) increases in the first two complexes but the equatorial bond lengths remain virtually unchanged, while d(Co)(-)(NB3) remains unchanged and the average d(Co)(-)(N(eq)) decreases in 10-Cl-MeCbl. Furthermore, the partial charge on chlorine increases as the donor power of X increases. The small decrease in the pK(a) of coordinated H(2)O in 10-Cl-H(2)OCbl(+) compared to H(2)OCbl(+) itself (7.65 vs 8.09) is due to a decreased charge density on oxygen in 10-Cl-OHCbl compared to OHCbl. The picture that emerges, therefore, is of competitive electron donation by X and Cl toward the corrin system. In 10-Cl-CNCbl, the decrease in the C&tbd1;N bond length as Co-C increases compared to CNCbl suggests that dpi-ppi bonding between cobalt and cyanide is important. (13)C and (15)N NMR observations on 10-Cl-(13)C(15)NCbl are consistent with these effects.

Evaluation of gases, condensates, and SO2 emissions from Augustine volcano, Alaska: the degassing of a Cl-rich volcanic system

USGS Publications Warehouse

Symonds, R.B.; Rose, William I.; Gerlach, T.M.; Briggs, P.H.; Harmon, R.S.

1990-01-01

After the March-April 1986 explosive eruption a comprehensive gas study at Augustine was undertaken in the summers of 1986 and 1987. Airborne COSPEC measurements indicate that passive SO2 emission rates declined exponentially during this period from 380??45 metric tons/day (T/D) on 7/24/86 to 27??6 T/D on 8/24/87. These data are consistent with the hypothesis that the Augustine magma reservoir has become more degassed as volcanic activity decreased after the spring 1986 eruption. Gas samples collected in 1987 from an 870??C fumarole on the andesitic lava dome show various degrees of disequilibrium due to oxidation of reduced gas species and condensation (and loss) of H2O in the intake tube of the sampling apparatus. Thermochemical restoration of the data permits removal of these effects to infer an equilibrium composition of the gases. Although not conclusive, this restoration is consistent with the idea that the gases were in equilibrium at 870??C with an oxygen fugacity near the Ni-NiO buffer. These restored gas compositions show that, relative to other convergent plate volcanoes, the Augustine gases are very HCl rich (5.3-6.0 mol% HCl), S rich (7.1 mol% total S), and H2O poor (83.9-84.8 mol% H2O). Values of ??D and ??18O suggest that the H2O in the dome gases is a mixture of primary magmatic water (PMW) and local seawater. Part of the Cl in the Augustine volcanic gases probably comes from this shallow seawater source. Additional Cl may come from subducted oceanic crust because data by Johnston (1978) show that Cl-rich glass inclusions in olivine crystals contain hornblende, which is evidence for a deep source (>25km) for part of the Cl. Gas samples collected in 1986 from 390??-642??C fumaroles on a ramp surrounding the inner summit crater have been oxidized so severely that restoration to an equilibrium composition is not possible. H and O isotope data suggest that these gases are variable mixtures of seawater, FMW, and meteoric steam. These samples are much more H2O-rich (92%-97% H2O) than the dome gases, possibly due to a larger meteoric steam component. The 1986 samples also have higher Cl/S, S/C, and F/Cl ratios, which imply that the magmatic component in these gases is from the more degassed 1976 magma. Thus, the 1987 samples from the lava dome are better indicators than the 1986 samples of degassing within the Augustine magma reservoir, even though they were collected a year later and contain a significant seawater component. Future gas studies at Augustine should emphasize fumaroles on active lava domes. Condensates collected from the same lava-dome fumarole have enrichments ot 107-102 in Cl, Br, F, B, Cd, As, S, Bi, Pb, Sb, Mo, Zn, Cu, K, Li, Na, Si, and Ni. Lower-temperature (200??-650??C) fumaroles around the volcano are generally less enriched in highly volatile elements. However, these lower-termperature fumaroles have higher concentration of rock-forming elements, probably derived from the wall rock. ?? 1990 Springer-Verlag.

Evaluation of gases, condensates, and SO2 emissions from Augustine volcano, Alaska: the degassing of a Cl-rich volcanic system

NASA Astrophysics Data System (ADS)

Symonds, Robert B.; Rose, William I.; Gerlach, Terrence M.; Briggs, Paul H.; Harmon, Russell S.

1990-05-01

After the March April 1986 explosive eruption a comprehensive gas study at Augustine was undertaken in the summers of 1986 and 1987. Airborne COSPEC measurements indicate that passive SO2 emission rates declined exponentially during this period from 380±45 metric tons/day (T/D) on 7/24/86 to 27±6 T/D on 8/24/87. These data are consistent with the hypothesis that the Augustine magma reservoir has become more degassed as volcanic activity decreased after the spring 1986 eruption. Gas samples collected in 1987 from an 870°C fumarole on the andesitic lava dome show various degrees of disequilibrium due to oxidation of reduced gas species and condensation (and loss) of H2O in the intake tube of the sampling apparatus. Thermochemical restoration of the data permits removal of these effects to infer an equilibrium composition of the gases. Although not conclusive, this restoration is consistent with the idea that the gases were in equilibrium at 870°C with an oxygen fugacity near the Ni-NiO buffer. These restored gas compositions show that, relative to other convergent plate volcanoes, the Augustine gases are very HCl rich (5.3 6.0 mol% HCl), S rich (7.1 mol% total S), and H2O poor (83.9 84.8 mol% H2O). Values of δD and δ18O suggest that the H2O in the dome gases is a mixture of primary magmatic water (PMW) and local seawater. Part of the Cl in the Augustine volcanic gases probably comes from this shallow seawater source. Additional Cl may come from subducted oceanic crust because data by Johnston (1978) show that Cl-rich glass inclusions in olivine crystals contain hornblende, which is evidence for a deep source (>25km) for part of the Cl. Gas samples collected in 1986 from 390° 642°C fumaroles on a ramp surrounding the inner summit crater have been oxidized so severely that restoration to an equilibrium composition is not possible. H and O isotope data suggest that these gases are variable mixtures of seawater, FMW, and meteoric steam. These samples are much more H2O-rich (92% 97% H2O) than the dome gases, possibly due to a larger meteoric steam component. The 1986 samples also have higher Cl/S, S/C, and F/Cl ratios, which imply that the magmatic component in these gases is from the more degassed 1976 magma. Thus, the 1987 samples from the lava dome are better indicators than the 1986 samples of degassing within the Augustine magma reservoir, even though they were collected a year later and contain a significant seawater component. Future gas studies at Augustine should emphasize fumaroles on active lava domes. Condensates collected from the same lava-dome fumarole have enrichments ot 107 102 in Cl, Br, F, B, Cd, As, S, Bi, Pb, Sb, Mo, Zn, Cu, K, Li, Na, Si, and Ni. Lower-temperature (200° 650°C) fumaroles around the volcano are generally less enriched in highly volatile elements. However, these lower-termperature fumaroles have higher concentration of rock-forming elements, probably derived from the wall rock.

Department of Defense Contractor Establishment Code (CEC). Alphabet Listing. Volume 1

DTIC Science & Technology

1992-11-01

Z1. A >W Z O -z OC U Uex0 -M: 8-..0 -a .w3L.PZU IL K4z0. ~ - ~ t IN -a 0U ZUý.U A ýM . 0UW p0.0pc~-~U am1010 Pco 0.~CI2201.4 1 -4 UZ0. w4 l4 1 P o... ERS1 0U 00 O . 0 N C.00 CI0 1O ClC , C 0t5~b. 0~ 0 L" F5 ~-C~1 0 t- ~ 0 ?o: wOO C O 0 O 0 O C~ C8Nt- j- ccC0 10 * CO00 W 0g- ONO inooWON2m r- -- 0 0 N ý...z .~ j~..Z ~ C~.kJ 091.09 5 0 ao~ o W-Z 1 . PCO 0 3J 2 Z .W C" -4 -u 9z z z m -o0 rQ E ~ ~ ~ i iz QzH .9 HUO0 ~ >0 Q 3 02 4 * mQ0 00 M0 rn0 0U

Synthesis, structure, photoluminescence and antitumour activity of zinc complex based on 2-(2-(1H-benzo-[d]imidazol-2-yl)benzyl)-1H-benzo-[d]imidazole

NASA Astrophysics Data System (ADS)

Che, Zhijian; Wang, Shaoxiang; Liu, Shenggui; Li, Guobi; Wu, Qiting; Lin, Chunyu; Kong, Linglang; Wang, Sheng

2015-01-01

A new complex [Zn(bbb)Cl2]·DMF, where bbb is 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole, was synthesized and characterized by element analysis, 1H NMR and X-ray single crystal structure analyses. For complex: crystal system, triclinic, space group, P-1, a = 9.4661(13), b = 10.3534(14), c = 13.0025(18) Å, α = 73.477(2), β = 80.743(2), γ = 88.658(2)°, V = 1205.5(3) Å3, Z = 2. In this complex, the Zn2+ distorted tetrahedron geometry is coordinated by two nitrogen atoms from 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole and two Cl-. The complex emits yellow green luminescence with the maximal emission peak at 550 nm in DMF solution. The complex exhibits inhibition on the growth of Eca109 cancer cell with IC50 value of 8.9 ± 1.1 μM, which was lower than that of cisplatin (14.3 ± 1.4 μM). This complex has potential application in treatment of esophageal cancer.

Exploring the plasma chemistry in microwave chemical vapor deposition of diamond from C/H/O gas mixtures.

PubMed

Kelly, Mark W; Richley, James C; Western, Colin M; Ashfold, Michael N R; Mankelevich, Yuri A

2012-09-27

Microwave (MW)-activated CH(4)/CO(2)/H(2) gas mixtures operating under conditions relevant to diamond chemical vapor deposition (i.e., X(C/Σ) = X(elem)(C)/(X(elem)(C) + X(elem)(O)) ≈ 0.5, H(2) mole fraction = 0.3, pressure, p = 150 Torr, and input power, P = 1 kW) have been explored in detail by a combination of spatially resolved absorption measurements (of CH, C(2)(a), and OH radicals and H(n = 2) atoms) within the hot plasma region and companion 2-dimensional modeling of the plasma. CO and H(2) are identified as the dominant species in the plasma core. The lower thermal conductivity of such a mixture (cf. the H(2)-rich plasmas used in most diamond chemical vapor deposition) accounts for the finding that CH(4)/CO(2)/H(2) plasmas can yield similar maximal gas temperatures and diamond growth rates at lower input powers than traditional CH(4)/H(2) plasmas. The plasma chemistry and composition is seen to switch upon changing from oxygen-rich (X(C/Σ) < 0.5) to carbon-rich (X(C/Σ) > 0.5) source gas mixtures and, by comparing CH(4)/CO(2)/H(2) (X(C/Σ) = 0.5) and CO/H(2) plasmas, to be sensitive to the choice of source gas (by virtue of the different prevailing gas activation mechanisms), in contrast to C/H process gas mixtures. CH(3) radicals are identified as the most abundant C(1)H(x) [x = 0-3] species near the growing diamond surface within the process window for successful diamond growth (X(C/Σ) ≈ 0.5-0.54) identified by Bachmann et al. (Diamond Relat. Mater.1991, 1, 1). This, and the findings of similar maximal gas temperatures (T(gas) ~2800-3000 K) and H atom mole fractions (X(H)~5-10%) to those found in MW-activated C/H plasmas, points to the prevalence of similar CH(3) radical based diamond growth mechanisms in both C/H and C/H/O plasmas.

Molten salt corrosion behavior of structural materials in LiCl-KCl-UCl3 by thermogravimetric study

NASA Astrophysics Data System (ADS)

Rao, Ch Jagadeeswara; Ningshen, S.; Mallika, C.; Mudali, U. Kamachi

2018-04-01

The corrosion resistance of structural materials has been recognized as a key issue in the various unit operations such as salt purification, electrorefining, cathode processing and injection casting in the pyrochemical reprocessing of spent metallic nuclear fuels. In the present work, the corrosion behavior of the candidate materials of stainless steel (SS) 410, 2.25Cr-1Mo and 9Cr-1Mo steels was investigated in molten LiCl-KCl-UCl3 salt by thermogravimetric analysis under inert and reactive atmospheres at 500 and 600 °C, for 6 h duration. Insignificant weight gain (less than 1 mg/cm2) in the inert atmosphere and marginal weight gain (maximum 5 mg/cm2) in the reactive atmosphere were observed at both the temperatures. Chromium depletion rates and formation of Cr-rich corrosion products increased with increasing temperature of exposure in both inert and reactive atmospheres as evidenced by SEM and EDS analysis. The corrosion attack by LiCl-KCl-UCl3 molten salt, under reactive atmosphere for 6 h duration was more in the case of SS410 than 9Cr-1Mo steel followed by 2.25Cr-1Mo steel at 500 °C and the corrosion attack at 600 °C followed the order: 9Cr-1Mo steel >2.25Cr-1Mo steel > SS410. Outward diffusion of the minor alloying element, Mo was observed in 9Cr-1Mo and 2.25Cr-1Mo steels at both temperatures under reactive atmosphere. Laser Raman spectral analysis of the molten salt corrosion tested alloys under a reactive atmosphere at 500 and 600 °C for 6 h revealed the formation of unprotected Fe3O4 and α-as well as γ-Fe2O3. The results of the present study facilitate the selection of structural materials for applications in the corrosive molten salt environment at high temperatures.

Intramolecular mobility of η(5)-ligands in chiral zirconocene complexes and the enantioselectivity of alkene functionalization by organoaluminum compounds.

PubMed

Parfenova, Lyudmila V; Zakirova, Irina V; Kovyazin, Pavel V; Karchevsky, Stanislav G; Istomina, Galina P; Khalilov, Leonard M; Dzhemilev, Usein M

2016-08-09

The effect of solvent nature (CD2Cl2, d8-toluene, d8-THF) on the conformational behavior of neomenthyl-substituted zirconocenes CpInd*ZrCl2 (Cp = η(5)-C5H5, Ind* = η(5)-neomenthylindenyl), CpCp'ZrCl2 (Cp = η(5)-C5H5, Cp' = η(5)-neomenthyl-4,5,6,7-tetrahydroindenyl), and Ind*2ZrCl2 (Ind* = η(5)-neomenthylindenyl) was shown by means of dynamic NMR spectroscopy, and the constants and thermodynamic parameters of conformer exchange were determined. The experimental conformational composition of the complexes was compared with structures obtained by quantum chemical modeling using the DFT methods PBE/3ζ and M06-2X/cc-pVDZ(H, C, Cl)/cc-pVDZ-PP(Zr), which predicted three rotamers in the case of both CpInd*ZrCl2 and CpCp'ZrCl2, and seven rotational isomers for Ind*2ZrCl2, three of these being C2-symmetric and the others being asymmetric. The enantioselectivity of the conformationally mobile complex Ind*2ZrCl2 in the reactions of terminal alkenes with AlR3 (R = Me, Et) was compared with that of rigid ansa-complexes, rac-p-S, p-S-[Y(η(5)-C9H10)2]ZrX2 (Y = SiMe2, C2H4; X = S-binaphtholate). Faster exchange between the conformers of Ind*2ZrCl2 in a chlorinated solvent gives the structural isomer of catalytically active sites, which affords higher substrate conversion and reaction enantioselectivity. Binding of the ligands to ansa-zirconocenes prevents the rotational isomerism of the complexes, providing the same configuration of the β-stereogenic center in the methyl- and ethylalumination products (unlike the conformationally mobile complex Ind*2ZrCl2) with an enantiomeric purity of 50-65%.

Synthesis and structure of tetranuclear orthometallated Pd(II) complexes derived from bis-iminophosphoranes.

PubMed

Bielsa, Raquel; Navarro, Rafael; Soler, Tatiana; Urriolabeitia, Esteban P

2008-04-07

The reaction of Pd(OAc)2 with bis-iminophosphoranes Ph3P=NCH2CH2CH2N=PPh3 (1a), [C6H4(C(O)N=PPh3)2-1,3] (1b) and [C6H4(C(O)N=PPh3)2-1,2] (1c), gives the orthopalladated tetranuclear complexes [{Pd(mu-Cl){C6H4(PPh2=NCH2-kappa-C,N)-2}}2CH2]2 (2a) [{Pd(mu-OAc){C6H4(PPh2=NC(O)-kappa-C,N)-2}}2C6H4-1',3']2 (2b) and [{Pd(mu-OAc){C6H4(PPh2=NC(O)-kappa-C,N)-2}}2C6H4-1',2']2 (2c). The reaction takes place in CH2Cl2 for 1a, but must be performed in glacial acetic acid for 1b and 1c. The process implies in all cases the activation of a C-H bond on a Ph ring of the phosphonium group, with concomitant formation of endo complexes. This is the expected behaviour for 1a, but for 1b and 1c reverses the exo orientation observed in other ketostabilized iminophosphoranes. The influence of the solvent in the orientation of the reaction is discussed. The dinuclear acetylacetonate complexes [{Pd(acac-O,O'){C6H4(PPh2=NCH2-kappa-C,N)-2}}2CH2] (3a), [{Pd(acac-O,O'){C6H4(PPh2=NC(O)-kappa-C,N)-2}}2C6H4-1',3'] (3b) and [{Pd(acac-O,O'){C6H4(PPh2=NC(O)-kappa-C,N)-2}}2C6H4-1',2'] (3c) have been obtained from the halide-bridging tetranuclear derivatives. The X-ray crystal structure of [3c.4CHCl3] is also reported.

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place. Part 9. (H and H Meat Products, Inc.-Iannucci and Son Con.)

DTIC Science & Technology

1989-01-01

8217 Cl - 4 enC )() COOIn-Mi I -4N(r4 N(\\J C C NN N lc04-. >N I 40(00 000 0 (NJ>om -4N(04L) 1 00 CIoOC ’o >0 0 I 20 0 0 Q n4 00 0 L ooQC IM 4(-4 C4 o a oI...1- Q( a ɘ ə a < LA-L-L) < 00(u0N D 0( W1 I’N D (D (DN 41 If 4( c I lle W M.-(--4.1000 U).- 4(D LA- LADO LA4 ( (0C 01.᝴ L -4 - 14-4 I-4 -4 -- of...Mooɜ IftVci 0I oU1 n107,I nL nI nI CaN InC) LALLAALL L -4 1.1Q(0 O C1(1Cim 1000 -00 1 f (D(0 f1 ENc nu nI nu )t nL)I r nI nu O L A L A L A L 10 C -i

Leifsonia psychrotolerans sp. nov., a psychrotolerant species of the family Microbacteriaceae from Livingston Island, Antarctica.

PubMed

Ganzert, Lars; Bajerski, Felizitas; Mangelsdorf, Kai; Lipski, André; Wagner, Dirk

2011-08-01

A cold-tolerant, yellow-pigmented, Gram-positive, motile, facultatively anaerobic bacterial strain, LI1(T), was isolated from a moss-covered soil from Livingston Island, Antarctica, near the Bulgarian station St. Kliment Ohridski. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a clade with the species Leifsonia kafniensis KFC-22(T), Leifsonia pindariensis PON10(T) and Leifsonia antarctica SPC-20(T), with which it showed sequence similarities of 99.0, 97.9 and 97.9 %, respectively. DNA-DNA hybridization revealed a reassociation value of 2.7 % with L. kafniensis LMG 24362(T). The DNA G+C content of strain LI1(T) was 64.5 mol%. The growth temperature range was -6 to 28 °C, with optimum growth at 16 °C. Growth occurred in 0-5 % NaCl and at pH 4.5-9.5, with optimum growth in 1-2 % NaCl and at pH 5.5-6.5. The predominant fatty acids were anteiso-C(15 : 0), C(18 : 0) and iso-C(15 : 0). The polar lipids were phosphatidylglycerol and diphosphatidylglycerol. Physiological and biochemical tests clearly differentiated strain LI1(T) from L. kafniensis. Therefore, a novel cold-tolerant species within the genus Leifsonia is proposed: Leifsonia psychrotolerans sp. nov. (type strain LI1(T) = DSM 22824(T) = NCCB 100313(T)).

Real-Space Bonding Indicator Analysis of the Donor-Acceptor Complexes X3BNY3, X3AlNY3, X3BPY3, and X3AlPY3 (X, Y = H, Me, Cl).

PubMed

Mebs, Stefan; Beckmann, Jens

2017-10-12

Calculations of real-space bonding indicators (RSBI) derived from Atoms-In-Molecules (AIM), Electron Localizability Indicator (ELI-D), Non-Covalent Interactions index (NCI), and Density Overlap Regions Indicator (DORI) toolkits for a set of 36 donor-acceptor complexes X 3 BNY 3 (1, 1a-1h), X 3 AlNY 3 (2, 2a-2h), X 3 BPY 3 (3, 3a-3h), and X 3 AlPY 3 (4, 4a-4h) reveal that the donor-acceptor bonds comprise covalent and ionic interactions in varying extents (X = Y = H for 1-4; X = H, Y = Me for 1a-4a; X = H, Y = Cl for 1b-4b; X = Me, Y = H for 1c-4c; X, Y = Me for 1d-4d; X = Me, Y = Cl for 1e-4e; X = Cl, Y = H for 1f-4f; X = Cl, Y = Me for 1g-4g; X, Y = Cl for 1h-4h). The phosphinoboranes X 3 BPY 3 (3, 3a-3h) in general and Cl 3 BPMe 3 (3f) in particular show the largest covalent contributions and the least ionic contributions. The aminoalanes X 3 AlNY 3 (2, 2a-2h) in general and Me 3 AlNCl 3 (2e) in particular show the least covalent contributions and the largest ionic contributions. The aminoboranes X 3 BNY 3 (1, 1a-1h) and the phosphinoalanes X 3 AlPY 3 (4, 4a-4h) are midway between phosphinoboranes and aminoalanes. The degree of covalency and ionicity correlates with the electronegativity difference BP (ΔEN = 0.15) < AlP (ΔEN = 0.58) < BN (ΔEN = 1.00) < AlN (ΔEN = 1.43) and a previously published energy decomposition analysis (EDA). To illustrate the importance of both contributions in Lewis formula representations, two resonance formulas should be given for all compounds, namely, the canonical form with formal charges denoting covalency and the arrow notation pointing from the donor to the acceptor atom to emphasis ionicity. If the Lewis formula mainly serves to show the atomic connectivity, the most significant should be shown. Thus, it is legitimate to present aminoalanes using arrows; however, for phosphinoboranes the canonical form with formal charges is more appropriate.

Secondary organic aerosol formation from propylene irradiations in a chamber study

NASA Astrophysics Data System (ADS)

Ge, Shuangshuang; Xu, Yongfu; Jia, Long

2017-05-01

Some studies have shown that low-molecular-weight VOCs such as ethylene and acetylene can form SOA. However, so far propylene (C3H6) has not been studied. The current work systematically investigates irradiations of propylene in the presence of NOx (x = 1, 2) in a self-made indoor chamber. Only a small amount of secondary organic aerosols (SOA) was formed under 5% and 80% RH conditions without sodium chloride (NaCl) seed particles or in the presence of solid NaCl. When NaCl was in the form of droplets, liquid water content (LWC) increased from 34.5 to 169.8 μg m-3 under different initial NaCl concentrations, and correspondingly the amount of SOA linearly increased from 5.9 to 29.8 μg m-3 (SOA = 0.0164 × LWC+1.137, R2 = 0.97) at the C3H6/NOx ratio of 32.2-44.9 (ppbC/ppb). The initial C3H6/NOx concentration ratio considerably impacted the formation of SOA, in which the amount of SOA increased from 12.1 to 47.9 μg m-3 exponentially as the ratio decreased from 46.5 to 6.3 with an important point of the ratio value of 11. At the ratio of less than 11 in the regime under the control of C3H6, SOA concentrations decreased considerably with increasing ratio, whereas at the ratio value of larger than 11 in the NOx controlled regime, SOA slightly decreased with increasing ratio. From combination of the analysis of different functional groups of particles by IR spectra and ESI-Exactive-Orbitrap mass spectrometer, the constituents of SOA were identified to be hydroperoxides (e.g. HOCH2CCl(CH3)OOH), esters (e.g. CH2ClC(O)OCHClCHO), organic nitrates (e.g. HO2CH(CH2Cl)C(O)OCCl(CH2Cl)C(O)OCHClCH2ONO2), etc. Furthermore, a liquid-phase mechanism of SOA formation has been proposed in this study.

Synthesis, structural characterization, Hirshfeld surface analysis and spectroscopic studies of cadmium (II) chloride complex with 4-hydroxy-1-methylpiperidine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soudani, S.; Ferretti, V.; Jelsch, C.

The chemical preparation, crystal structure, Hirshfeld surface analysis and spectroscopic characterization of the novel cadmium (II) 4-hydroxy-1-methylpiperidine complex, Cd{sub 4}Cl{sub 10}(C{sub 6}H{sub 14}NO){sub 2}·2H{sub 2}O, have been reported. The atomic arrangement can be described as built up by an anionic framework, formed by edge sharing CdCl{sub 6} and CdCl{sub 5}O octahedral linear chains spreading along the a-axis. These chains are interconnected by water molecules via O–H⋯Cl and O–H⋯O hydrogen bonds to form layers parallel to (011) plane. The organic cations are inserted between layers through C–H⋯Cl hydrogen bonds. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis revealsmore » that the H{sub C}⋯Cl and H{sub C}⋯H{sub C} intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The statistical analysis of crystal contacts reveals the driving forces in the packing formation. The {sup 13}C and {sup 15}N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.« less

Very large cooperative effects in heterobimetallic titanium-chromium catalysts for ethylene polymerization/copolymerization.

PubMed

Liu, Shaofeng; Motta, Alessandro; Mouat, Aidan R; Delferro, Massimiliano; Marks, Tobin J

2014-07-23

The heterobimetallic complexes, (η(5)-indenyl)[1-Me2Si((t)BuN)TiCl2]-3-CnH2n-[N,N-bis(2-(ethylthio)ethyl)amine]CrCl3 (n = 0, Ti-C0-Cr(SNS); n = 2, Ti-C2-Cr(SNS); n = 6, Ti-C6-Cr(SNS)), (η(5)-indenyl)[1-Me2Si((t)BuN)TiCl2]-3-C2H4-[N,N-bis((o-OMe-C6H4)2P)amine]CrCl3 (Ti-C2-Cr(PNP)), and (η(5)-indenyl)[1-Me2Si((t)BuN)TiCl2]-3-C2H4-[N,N-bis((diethylamine)ethyl)-amine]CrCl3 (Ti-C2-Cr(NNN)), are synthesized, fully characterized, and employed as olefin polymerization catalysts. With ethylene as the feed and MAO as cocatalyst/activator, SNS-based complexes Ti-C0-Cr(SNS), Ti-C2-Cr(SNS), and Ti-C6-Cr(SNS) afford linear low-density polyethylenes (LLDPEs) with exclusive n-butyl branches (6.8-25.8 branches/1000 C), while under identical polymerization conditions Ti-C2-Cr(PNP) and Ti-C2-Cr(NNN) produce polyethylenes with heterogeneous branching (C2, C4, and C≥6) or negligible branching, respectively. Under identical ethylene polymerization conditions, Ti-C0-Cr(SNS) produces polyethylenes with higher activity (4.5× and 6.1×, respectively), Mn (1.3× and 1.8×, respectively), and branch density (1.4× and 3.8×, respectively), than Ti-C2-Cr(SNS) and Ti-C6-Cr(SNS). Versus a CGC(Et)Ti + SNSCr tandem catalyst, Ti-C0-Cr(SNS) yields polyethylene with somewhat lower activity, but with 22.6× higher Mn and 4.0× greater branching density under identical conditions. In ethylene +1-pentene competition experiments, Ti-C0-Cr(SNS) yields 5.5% n-propyl branches and 94.5% n-butyl branches at [1-pentene] = 0.1 M, and the estimated effective local concentration of 1-hexene is ∼8.6 M. In contrast, the tandem CGC(Et)Ti + SNSCr system yields 91.0% n-propyl branches under identical reaction conditions. The homopolymerization and 1-pentene competition results argue that close Ti···Cr spatial proximity together with weak C-H···Ti and C-H···S interactions significantly influence relative 1-hexene enchainment and chain transfer rates, supported by DFT computation, and that such effects are conversion insensitive but cocatalyst and solvent sensitive.

Investigation of Sensitivities and Drift Effects of the Arrayed Flexible Chloride Sensor Based on RuO₂/GO at Different Temperatures.

PubMed

Tseng, Shi-Chang; Wu, Tong-Yu; Chou, Jung-Chuan; Liao, Yi-Hung; Lai, Chih-Hsien; Yan, Siao-Jie; Tseng, Ting-Wei

2018-02-20

We investigate the temperature effect on sensing characteristics and drift effect of an arrayed flexible ruthenium dioxide (RuO₂)/graphene oxide (GO) chloride sensor at different solution temperatures between 10 °C and 50 °C. The average sensor sensitivities according to our experimental results were 28.2 ± 1.4 mV/pCl (10 °C), 42.5 ± 2.0 mV/pCl (20 °C), 47.1 ± 1.8 mV/pCl (30 °C), 54.1 ± 2.01 mV/pCl (40 °C) and 46.6 ± 2.1 mV/pCl (50 °C). We found the drift effects of an arrayed flexible RuO₂/GO chloride sensor in a 1 M NaCl solution to be between 8.2 mV/h and 2.5 mV/h with solution temperatures from 10 °C to 50 °C.

Investigation of Sensitivities and Drift Effects of the Arrayed Flexible Chloride Sensor Based on RuO2/GO at Different Temperatures

PubMed Central

Tseng, Shi-Chang; Wu, Tong-Yu; Liao, Yi-Hung; Lai, Chih-Hsien; Yan, Siao-Jie; Tseng, Ting-Wei

2018-01-01

We investigate the temperature effect on sensing characteristics and drift effect of an arrayed flexible ruthenium dioxide (RuO2)/graphene oxide (GO) chloride sensor at different solution temperatures between 10 °C and 50 °C. The average sensor sensitivities according to our experimental results were 28.2 ± 1.4 mV/pCl (10 °C), 42.5 ± 2.0 mV/pCl (20 °C), 47.1 ± 1.8 mV/pCl (30 °C), 54.1 ± 2.01 mV/pCl (40 °C) and 46.6 ± 2.1 mV/pCl (50 °C). We found the drift effects of an arrayed flexible RuO2/GO chloride sensor in a 1 M NaCl solution to be between 8.2 mV/h and 2.5 mV/h with solution temperatures from 10 °C to 50 °C. PMID:29461506

Zinc(II) complexes with potent cyclin-dependent kinase inhibitors derived from 6-benzylaminopurine: synthesis, characterization, X-ray structures and biological activity.

PubMed

Trávnícek, Zdenek; Krystof, Vladimír; Sipl, Michal

2006-02-01

The synthesis, characterization and biological activity of the first zinc(II) complexes with potent inhibitors of cyclin-dependent kinases (CDKs) derived from 6-benzylaminopurine are described. Based on the results following from elemental analyses, infrared, NMR and ES+MS (electrospray mass spectra in the positive ion mode) spectroscopies, conductivity data, thermal analysis and X-ray structures, the tetrahedral Zn(II) complexes of the compositions [Zn(Olo)Cl(2)](n) (1), [Zn(iprOlo)Cl(2)](n) (2), [Zn(BohH(+))Cl(3)] x H(2)O (3) and [Zn(iprOloH(+))Cl(3)] x H(2)O (4) have been prepared, where Olo=2-(2-hydroxyethylamino)-6-benzylamino-9-methylpurine (Olomoucine), iprOlo=2-(2-hydroxyethylamino)-6-benzylamino-9-isopropylpurine (i-propyl-Olomoucine), Boh=2-(3-hydroxypropylamino)-6-benzylamino-9-isopropylpurine (Bohemine). The 1D-polymeric chain structure for [Zn(Olo)Cl(2)](n) (1) as well as the monomeric one for [Zn(BohH(+))Cl(3)] x H(2)O (3) and [Zn(iprOloH(+))Cl(3)] x H(2)O (4) have been revealed unambiguously by single crystal X-ray analyses. The 1D-polymeric chain of 1 consists of Zn(Olo)Cl(2) monomeric units in which the Zn(II) ion is coordinated by two chlorine atoms and one oxygen atom of the 2-hydroxyethylamino group of Olomoucine. The next monomeric unit is bonded to Zn(II) through the N7 atom of a purine ring. Thus, each of Zn(II) ions is tetrahedrally coordinated and a ZnCl(2)NO chromophore occurs in the complex 1. The complexes 3 and 4 are mononuclear species with a distorted tetrahedral arrangement of donor atoms around the Zn(II) ion with a ZnCl(3)N chromophore. The corresponding CDK inhibitor, i.e., both Boh and iprOlo, is coordinated to Zn(II) via the N7 atom of the purine ring in 3 and 4. The cytotoxicity of the zinc(II) complexes against human melanoma, sarcoma, leukaemia and carcinoma cell lines has been determined as well as the inhibition of the CDK2/cyclin E kinase. A relationship between the structure and biological activity of the complexes is also discussed.

Ruthenium chalcogenonitrosyl and bridged nitrido complexes containing chelating sulfur and oxygen ligands.

PubMed

Ng, Ho-Yuen; Cheung, Wai-Man; Kwan Huang, Enrique; Wong, Kang-Long; Sung, Herman H-Y; Williams, Ian D; Leung, Wa-Hung

2015-11-14

Ruthenium thio- and seleno-nitrosyl complexes containing chelating sulfur and oxygen ligands have been synthesised and their de-chalcogenation reactions have been studied. The reaction of mer-[Ru(N)Cl3(AsPh3)2] with elemental sulfur and selenium in tetrahydrofuran at reflux afforded the chalcogenonitrosyl complexes mer-[Ru(NX)Cl3(AsPh3)2] [X = S (1), Se (2)]. Treatment of 1 with KN(R2PS)2 afforded trans-[Ru(NS)Cl{N(R2PS)2}2] [R = Ph (3), Pr(i) (4), Bu(t) (5)]. Alternatively, the thionitrosyl complex 5 was obtained from [Bu(n)4N][Ru(N)Cl4] and KN(Bu(t)2PS)2, presumably via sulfur atom transfer from [N(Bu(t)2PS)2](-) to the nitride. Reactions of 1 and 2 with NaLOEt (LOEt(-) = [Co(η(5)-C5H5){P(O)(LOEt)2}3](-)) gave [Ru(NX)LOEtCl2] (X = S (8), Se (9)). Treatment of [Bu(n)4N][Ru(N)Cl4] with KN(R2PS)2 produced Ru(IV)-Ru(IV)μ-nitrido complexes [Ru2(μ-N){N(R2PS)2}4Cl] [R = Ph (6), Pr(i) (7)]. Reactions of 3 and 9 with PPh3 afforded 6 and [Ru(NPPh3)LOEtCl2], respectively. The desulfurisation of 5 with [Ni(cod)2] (cod = 1,5-cyclooctadiene) gave the mixed valance Ru(III)-Ru(IV)μ-nitrido complex [Ru2(μ-N){N(Bu(t)2PS)2}4] (10) that was oxidised by [Cp2Fe](PF6) to give the Ru(IV)-Ru(IV) complex [Ru2(μ-N){N(Bu(t)2PS)2}4](PF6) ([10]PF6). The crystal structures of 1, 2, 3, 7, 9 and 10 have been determined.

[CuCl(n)](2-n) ion-pair species in 1-ethyl-3-methylimidazolium chloride ionic liquid-water mixtures: ultraviolet-visible, X-ray absorption fine structure, and density functional theory characterization.

PubMed

Li, Guosheng; Camaioni, Donald M; Amonette, James E; Zhang, Z Conrad; Johnson, Timothy J; Fulton, John L

2010-10-07

We studied the coordination environment about Cu(II) in a pure ionic liquid, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl), and in binary mixtures of this compound with water across the entire range of compositions, using a combination of X-ray absorption fine structure (XAFS), ultraviolet-visible (UV-vis) spectroscopy, and electronic structure calculations. Our results show a series of stages in the ion pairing of the divalent cation, Cu(II), including the contact ion pairing of Cu(2+) with multiple Cl(-) ligands to form various CuCl(n)((2-n)) polyanions, as well as the subsequent solvation and ion pairing of the polychlorometallate anion with the EMIM(+) cation. Ion-pair formation is strongly promoted in [EMIM]Cl by the low dielectric constant and by the extensive breakdown of the water hydrogen-bond network in [EMIM]Cl-water mixtures. The CuCl(4)(2-) species dominates in the [EMIM]Cl solvent, and calculations along with spectroscopy show that its geometry distorts to C(2) symmetry compared to D(2d) in the gas phase. These results are important in understanding catalysis and separation processes involving transition metals in ionic liquid systems.

Characterization of the human pH- and PKA-activated ClC-2G(2 alpha) Cl- channel.

PubMed

Sherry, A M; Stroffekova, K; Knapp, L M; Kupert, E Y; Cuppoletti, J; Malinowska, D H

1997-08-01

A ClC-2G(2 alpha) Cl- channel was identified to be present in human lung and stomach, and a partial cDNA for this Cl- channel was cloned from a human fetal lung library. A full-length expressible human ClC-2G(2 alpha) cDNA was constructed by ligation of mutagenized expressible rabbit ClC-2G(2 alpha) cDNA with the human lung ClC-2G(2 alpha) cDNA, expressed in oocytes, and characterized at the single-channel level. Adenosine 3',5'-cyclic monophosphate-dependent protein kinase (PKA) treatment increased the probability of opening of the channel (Po). After PKA activation, the channel exhibited a linear (r = 0.99) current-voltage curve with a slope conductance of 22.1 +/- 0.8 pS in symmetric 800 mM tetraethylammonium chloride (TEACl; pH 7.4). Under fivefold gradient conditions of TEACl, a reversal potential of +21.5 +/- 2.8 mV was measured demonstrating anion-to-cation discrimination. As previously demonstrated for the rabbit ClC-2G(2 alpha) Cl- channel, the human analog, hClC-2G(2 alpha), was active at pH 7.4 as well as when the pH of the extracellular face of the channel (trans side of the bilayer; pHtrans) was asymmetrically reduced to pH 3.0. The extent of PKA activation was dependent on pHtrans. With PKA treatment, Po increased fourfold with a pHtrans of 7.4 and eightfold with a pHtrans of 3.0. Effects of sequential PKA addition followed by pHtrans reduction on the same channel suggested that the PKA- and pH-dependent increases in channel Po were separable and cumulative. Northern analysis showed ClC-2G(2 alpha) mRNA to be present in human adult and fetal lung and adult stomach, and quantitative reverse transcriptase-polymerase chain reaction showed this channel to be present in the adult human lung and stomach at about one-half the level found in fetal lung. The findings of the present study suggest that the ClC-2G(2 alpha) Cl- channel may play an important role in Cl- transport in the fetal and adult human lung.

Unexpected formation of 1-[4-chloromethylphenyl]-5-[4-(methylsulfonyl)benzyl]-1H-tetrazole and 1-[4-chloromethylphenyl]-5-[4-(aminosulfonyl)phenyl]-1H-tetrazole: Crystal structure, bioassay screening and molecular docking studies

NASA Astrophysics Data System (ADS)

Jawabrah Al-Hourani, Baker; Ali, Basem F.; Judeh, Zaher; El-Barghouthi, Musa I.; Al-Awaida, Wajdy; Snobar, Yasmin; El Soubani, Fatima; Matalka, Khalid; Wuest, Frank

2018-07-01

During the cyclization reaction of benzyl alcohol containing amides, using NaN3 and SiCl4, additional unique chlorination development was observed to yield the novel azoles 1-[4-chloromethylphenyl]-5-[4-(methylsulfonyl)benzyl]-1H-tetrazole (3a) and 1-[4-chloromethylphenyl]-5-[4-(aminosulfonyl)phenyl]-1H-tetrazole (3b). Control experiments showed that the SiCl4 or SiCl3N3 has the major role for such functional group transformation in such a clean reaction and quantitative yield. Their molecular structures have been ascertained using the X-ray crystallography technique in addition to the spectroscopic analyses. Both compounds 3a and 3b crystallize in the monoclinic space group P21/c. The cell parameters of azole 3a are a = 22.3827 (8), Å, b = 5.1602 (2) Å, c = 13.4994 (5) Å3, β = 95.2352 (14)°, V = 1552.67 (10) Å3, and Z = 4. While the cell parameters of azole 3b are a = 20.582 (2), Å, b = 5.8947 (7) Å, c = 13.0796 (16) Å3, β = 104.376 (4)°, V = 1537.2 (3) Å3, and Z = 4. The central tetrazole ring of both compounds is planar and bears (4-chloromethylphenyl) at position one (N-1) of the central moiety. However, the substituents 4-(methylsulfonyl)phenyl and 4-(aminosulfonyl)phenyl of azoles 3a and 3b, respectively, are attached to the C-5 of the same central unit. The phenyl rings at N-1, (C2sbnd C7) and C9sbnd C14 in (3a); (C2sbnd C7) and (C8sbnd C14) in (3b) are inclined compared to the tetrazole ring with dihedral angles of 21.74° and 83.94° in 3a and 25.85° and 65.13° in 3b. The two phenyl rings, at N-1 and C-5, are rotated against each other by 87.73° (in 3a) and 72.21° (in 3b). In the crystal, intermolecular interactions between molecules of 3a,b are dominated by Csbnd H⋯O and Csbnd H⋯N hydrogen bonds. Additional Cl…π interactions add extra supramolecularity. All intermolecular interaction motifs consolidate a three dimensional network lattice. The molecular docking studies were carried out to understand the interaction of compounds 3a and 3b within the active site of the cyclooxygenase-2 enzyme, followed by a comparison study with the celecoxib drug as a reference compound. The in vitro bioassay screenings of azoles 3a and 3b showed that both compounds have poor selectivity and weak inhibition potency toward cyclooxygenase-2 enzyme.

Synthesis of Bisimidazole Derivatives for Selective Sensing of Fluoride Ion.

PubMed

Zhang, Liang; Liu, Fang

2017-09-11

Rapid and efficient analysis of fluoride ion is crucial to providing key information for fluoride ion hazard assessment and pollution management. In this study, we synthesized one symmetrical structure called 1,4-bis(4,5-diphenyl-1 H -imidazol-2-yl)benzene ( 1a ) and two asymmetrical structures, namely 2-(4-(4,5-diphenyl-1 H -imidazol-2-yl)phenyl)-1 H -phenanthro(9,10- d )imidazole ( 1b ) and 2-(4-(4,5-diphenyl-1 H -imidazol-2-yl)phenyl)-1 H -imidazo(4,5- f )(1,10)phenanthroline ( 1c ), which served as an efficient anion sensor for fluoride ion over a wide range of other anions (Cl - , Br - , I - , NO₃ - , ClO₄ - , HSO₄ - , BF₄ - , and PF₆ - ) owing to imidazole group in the main backbone. The absorption intensity of compound 1a at λ max 358 nm slightly decreased; however, a new band at λ max 414 nm appeared upon the addition of fluoride ion, while no evident change occurred upon the addition of eight other anions. The photoluminescence intensity of compound 1a at λ max 426 nm was nearly quenched and fluorescence emission spectra were broadened when fluoride ion was added into dimethyl sulfoxide (DMSO) solution of compound 1a . Compared with the optical behaviors of the DMSO solution of compound 1a in the presence of Bu₄N⁺F - , compounds 1b and 1c exhibited considerable sensitivity to fluoride ion due to the increase in coplanarity. Furthermore, compared with the fluorescence emission behaviors of the DMSO solutions of compounds 1a and 1b in the presence of Bu₄N⁺F - , compound 1c exhibited the most significant sensitivity to fluoride ion due to the charge transfer enhancement. Consequently, the detection limits of compounds 1a - 1 c increased from 5.47 × 10 -6 M to 4.21 × 10 -6 M to 9.12 × 10 -7 M. Furthermore, the largest red shift (75 nm) of the DMSO solution compound 1c in the presence of fluoride ion can be observed. Our results suggest that the increase in coplanarity and the introduction of electron-withdrawing groups to the imidazole backbone can improve the performance in detecting fluoride ion.

Structure cristalline et analyses thermique et de surface Hirshfeld du diperchlorate de 4-aza­niumyl-2,2,6,6-tétraméthylpipéridin-1-ium

PubMed Central

Boumakhla, Abdessalem; Zid, Mohamed Faouzi; Guesmi, Abderrahmen

2017-01-01

The synthesis of 4-aza­niumyl-2,2,6,6-tetra­methyl­piperidin-1-ium diperchlorate, C9H22N2 2+·2ClO4 −, was carried out from an aqueous reaction of perchloric acid with 4-amino-2,2,6,6-tetra­methyl­piperidine. This compound was characterized by TGA–DSC analysis and single-crystal X-ray diffraction. The piperidine ring of the dication adopts a chair conformation and the orientation of the C—NH3 bond is equatorial. One of the two crystallographically independent perchlorate anions exhibits disorder [occupancies 0.625 (7) and 0.375 (7)]. The crystal packing is constituted by a succession of mixed layers parallel to the (-102) plane, made up of C9H22N2 2+ dications and ClO4 − anions. These ions are linked by normal and bifurcated N—H⋯O hydrogen bonds with R 4 4(12) graph-set motifs, generating a two-dimensional network. The inter­molecular inter­actions in the crystal structure were qu­anti­fied and analysed using Hirshfeld surface analysis. PMID:29250357

Vinclozolin: 3-(3,5-di-chloro-phen-yl)-5-ethenyl-5-methyl-1,3-oxazolidine-2,4-dione.

PubMed

Cho, Seonghwa; Kim, Jineun; Lee, Sangjin; Kim, Tae Ho

2014-07-01

In the title compound, C12H9Cl2NO3, which is the fungicide vinclozolin, the dihedral angle between the oxazolidine ring mean plane [r.m.s. deviation = 0.029 Å] and the benzene ring is 77.55 (8)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming chains along [010]. The chains are linked by short Cl⋯Cl contacts [3.4439 (3) and 3.5798 (3) Å], resulting in a three-dimensional architecture.

Unprecedented Spectroscopic and Computational Evidence for Allenyl and Propargyl Titanocene(IV) Complexes: Electrophilic Quenching of Their Metallotropic Equilibrium.

PubMed

Ruiz-Muelle, Ana Belén; Oña-Burgos, Pascual; Ortuño, Manuel A; Oltra, J Enrique; Rodríguez-García, Ignacio; Fernández, Ignacio

2016-02-12

The synthesis and structural characterization of allenyl titanocene(IV) [TiClCp2 (CH=C=CH2 )] 3 and propargyl titanocene(IV) [TiClCp2 (CH2 -C≡C-(CH2 )4 CH3 )] 9 have been described for the first time. Advanced NMR methods including diffusion NMR methods (diffusion pulsed field gradient stimulated spin echo (PFG-STE) and DOSY) have been applied and established that these organometallics are monomers in THF solution with hydrodynamic radii (from the Stokes-Einstein equation) of 3.5 and 4.1 Å for 3 and 9, respectively. Full (1) H, (13) C, Δ(1) H, and Δ(13) C NMR data are given, and through the analysis of the Ramsey equation, the first electronic insights into these derivatives are provided. In solution, they are involved in their respective metallotropic allenyl-propargyl equilibria that, after quenching experiments with aromatic and aliphatic aldehydes, ketones, and protonating agents, always give the propargyl products P (when carbonyls are employed), or allenyl products A (when a proton source is added) as the major isomers. In all the cases assayed, the ratio of products suggests that the metallotropic equilibrium should be faster than the reactions of 3 and 9 with electrophiles. Indeed, DFT calculations predict lower Gibbs energy barriers for the metallotropic equilibrium, thus confirming dynamic kinetic resolution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Purification of used eutectic (LiCl-KCl) salt electrolyte from pyroprocessing

NASA Astrophysics Data System (ADS)

Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Choi, Jung-Hoon; Kim, In-Tae; Park, Geun-Il

2013-06-01

The separation characteristics of surrogate rare-earth fission products in a eutectic (LiCl-KCl) molten salt were investigated. This system is based on the eutectic salt used for the pyroprocessing treatment of used nuclear fuel (UNF). The investigation was performed using an integrated rare-earth separation apparatus comprising a precipitation reactor, a solid detachment device, and a layer separation device. To separate rare-earth fission products, a phosphate precipitation method using both Li3PO4 and K3PO4 as a precipitant was performed. The use of an equivalent phosphate precipitant composed of 0.408 molar ratio-K3PO4 and 0.592 molar ratio-Li3PO4 can preserve the original eutectic ratio, LiCl-0.592 molar ratio (or 45.2 wt%), as well as provide a high separation efficiency of over 99.5% under conditions of 550 °C and Ar sparging when using La, Nd, Ce, and Pr chlorides. The mixture of La, Nd, Ce, and Pr phosphate had a typical monoclinic (or monazite) structure, which has been proposed as a reliable host matrix for the permanent disposal of a high-level waste form. To maximize the reusability of purified eutectic waste salt after rare-earth separation, the successive rare-earth separation process, which uses both phosphate precipitation and an oxygen sparging method, were introduced and tested with eight rare-earth (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) chlorides. In the successive rare-earth separation process, the phosphate reaction was terminated within 1 h at 550 °C, and a 4-8 h oxygen sparging time were required to obtain over a 99% separation efficiency at 700-750 °C. The mixture of rare-earth precipitates separated by the successive rare-earth separation process was found to be phosphate, oxychloride, and oxide. Through the successive rare-earth separation process, the eutectic ratio of purified salt maintained its original value, and impurity content including the residual precipitant of purified salt can be minimized.

Dehydrogenation of secondary amines: synthesis, and characterization of rare-earth metal complexes incorporating imino- or amido-functionalized pyrrolyl ligands.

PubMed

Li, Qinghai; Zhou, Shuangliu; Wang, Shaowu; Zhu, Xiancui; Zhang, Lijun; Feng, Zhijun; Guo, Liping; Wang, Fenhua; Wei, Yun

2013-02-28

The dehydrogenation of pyrrolyl-functionalized secondary amines initiated by rare-earth metal amides was systematically studied. Reactions of the rare-earth metal amides [(Me(3)Si)(2)N](3)RE(μ-Cl)Li(THF)(3) with pyrrolyl-functionalized secondary amines 2-(t)BuNHCH(2)-5-R-C(4)H(2)NH (R = H (1), R = (t)Bu (2)) led to dehydrogenation of the secondary amines with isolation of imino-functionalized pyrrolyl rare-earth metal complexes [2-(t)BuN=CH-5-R-C(4)H(2)N](2)REN(SiMe(3))(2) (R = H, RE = Y (3a), Dy (3b), Yb (3c), Eu (3d); R = (t)Bu, RE = Y (4a), Dy (4b), Er (4c)). The mixed ligands erbium complex [2-(t)BuNCH(2)-5-(t)Bu-C(4)H(2)N]Er[2-(t)BuN=CH-5-(t)BuC(4)H(2)N](2)ClLi(2)(THF) (4c') was isolated in a short reaction time for the synthesis of complex 4c. Reaction of the deuterated pyrrolyl-functionalized secondary amine 2-((t)BuNHCHD)C(4)H(3)NH with yttrium amide [(Me(3)Si)(2)N](3)Y(μ-Cl)Li(THF)(3) further proved that pyrrolyl-amino ligands were transferred to pyrrolyl-imino ligands. Treatment of 2-((t)BuNHCH(2))C(4)H(3)NH (1) with excess (Me(3)Si)(2)NLi gave the only pyrrole deprotonated product {[η(5):η(2):η(1)-2-((t)BuNHCH(2))C(4)H(3)N]Li(2)N(SiMe(3))(2)}(2) (5), indicating that LiN(SiMe(3))(2) could not dehydrogenate the secondary amines to imines and rare-earth metal ions had a decisive effect on the dehydrogenation. The reaction of the rare-earth metal amides [(Me(3)Si)(2)N](3)RE(μ-Cl)Li(THF)(3) with 1 equiv. of more bulky pyrrolyl-functionalized secondary amine 2-[(2,6-(i)Pr(2)C(6)H(3))NHCH(2)](C(4)H(3)NH) (6) in toluene afforded the only amine and pyrrole deprotonated dinuclear rare-earth metal amido complexes {(μ-η(5):η(1)):η(1)-2-[(2,6-(i)Pr(2)C(6)H(3))NCH(2)]C(4)H(3)N]LnN(SiMe(3))(2)}(2) (RE = Nd (7a), Sm (7b), Er (7c)), no dehydrogenation of secondary amine to imine products were observed. On the basis of experimental results, a plausible mechanism for the dehydrogenation of secondary amines to imines was proposed.

A Trinuclear Ni(II) Enediolate Complex: Synthesis, Characterization, and O2 Reactivity

PubMed Central

Arif, Atta M.; Berreau, Lisa M.

2009-01-01

Using a new N4-donor chelate ligand having a mixture of hydrophobic phenyl and hydrogen bond donor appendages, a trinuclear Ni(II) complex of the doubly deprotonated form of 2-hydroxy-1,3-diphenylpropane-1,3-dione was isolated, characterized (X-ray crystallography, elemental analysis, UV-vis, 1H NMR, FTIR, magnetic moment measurement), and evaluated for O2 reactivity. This complex, [(6-NA-6-Ph2TPANi)2(μ-PhC(O)C(O)C(O)Ph)2Ni](ClO4)2 (4), has two terminal pseudo octahedral Ni(II) centers supported by the tetradentate chelate ligand, and a central square planar Ni(II) ion ligated by oxygen atoms of two bridging enediolate ligands. In CH3CN, 4 exhibits a deep orange/brown color and λmax = 463 nm (ε = 16,000 M-1cm-1). The room temperature magnetic moment of 4, determined by Evans method, is μeff = 5.3(2) μB. This is consistent with the presence of two non-interacting high-spin Ni(II) centers, a diamagnetic central Ni(II) ion, and an overall quintet ground state. Exposure of a CH3CN solution of 4 to O2 results in the rapid loss of the orange/brown color to give a green solution. The products identified from this reaction are [(κ3-6-NA-6-Ph2TPA)Ni(O2Ph)(H2O)]ClO4 (5), benzil (PhC(O)C(O)Ph), and CO. Identification of 5 was achieved via its independent synthesis and comparison of its 1H NMR and mass spectral features with those of the 6-NA-6-Ph2TPA-containing product generated upon reaction of 4 with O2. The independently prepared sample of 5 was characterized by X-ray crystallography, elemental analysis, UV-vis, mass spectrometry, and FTIR. The O2 reactivity of 4 has relevance to the active site chemistry of Ni(II)-containing acireductone dioxygenase (Ni(II)-ARD). PMID:18959363

Preparation and Single-Crystal X-Ray Structures of Four Related Mixed-Ligand 4-Methylpyridine Indium Halide Complexes

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Clark, Eric B.; Schupp, John D.; Williams, Jennifer N.; Duraj, Stan A.; Fanwick, Philip E.

2013-01-01

We describe the structures of four related indium complexes obtained during synthesis of solid-state materials precursors. Indium adducts of halides and 4-methylpyridine, InX3(pic)3 (X = Cl, Br; pic = 4-methylpyridine) consist of octahedral molecules with meridional (mer) geometry. Crystals of mer-InCl3(pic)3 (1) are triclinic, space group P1(bar) (No. 2), with a = 9.3240(3), b = 13.9580(6), c = 16.7268 (7) A, alpha = 84.323(2), beta = 80.938(2), gamma = 78.274(3)Z = 4, R = 0.035 for 8820 unique reflections. Crystals of mer-InBr3(pic)3 (2) are monoclinic, space group P21/n (No. 14), with a = 15.010(2), b = 19.938(2), c = 16.593(3), beta = 116.44(1)Z = 8, R = 0.053 for 4174 unique reflections. The synthesis and structures of related compounds with phenylsulfide (chloride) (3) and a dimeric complex with bridging hydroxide (bromide) (4) coordination is also described. Crystals of trans-In(SC6H5)Cl2(pic)3 (3) are monoclinic, space group P21/n (No. 14), with a = 9.5265(2), b = 17.8729(6), c = 13.8296(4), beta = 99.7640(15)Z = 4, R = 0.048 for 5511 unique reflections. Crystals of [In(mu-OH)Br2(pic)22 (4) are tetragonal, space group = I41cd (No. 110) with a = 19.8560(4), b = 19.8560(4), c = 25.9528(6), Z = 8, R = 0.039 for 5982 unique reflections.

Phase relations and adiabats in boiling seafloor geothermal systems

USGS Publications Warehouse

Bischoff, J.L.; Pitzer, Kenneth S.

1985-01-01

Observations of large salinity variations and vent temperatures in the range of 380-400??C suggest that boiling or two-phase separation may be occurring in some seafloor geothermal systems. Consideration of flow rates and the relatively small differences in density between vapors and liquids at the supercritical pressures at depth in these systems suggests that boiling is occurring under closed-system conditions. Salinity and temperature of boiling vents can be used to estimate the pressure-temperature point in the subsurface at which liquid seawater first reached the two-phase boundary. Data are reviewed to construct phase diagrams of coexisting brines and vapors in the two-phase region at pressures corresponding to those of the seafloor geothermal systems. A method is developed for calculating the enthalpy and entropy of the coexisting mixtures, and results are used to construct adiabats from the seafloor to the P-T two-phase boundary. Results for seafloor vents discharging at 2300 m below sea level indicate that a 385??C vent is composed of a brine (7% NaCl equivalent) in equilibrium with a vapor (0.1% NaCl). Brine constitutes 45% by weight of the mixture, and the fluid first boiled at approximately 1 km below the seafloor at 415??C, 330 bar. A 400??C vent is primarily vapor (88 wt.%, 0.044% NaCl) with a small amount of brine (26% NaCl) and first boiled at 2.9 km below the seafloor at 500??C, 520 bar. These results show that adiabatic decompression in the two-phase region results in dramatic cooling of the fluid mixture when there is a large fraction of vapor. ?? 1985.

Cd(II) and Zn(II) complexes of two new hexadentate Schiff base ligands derived from different aldehydes and ethanol amine; X-ray crystal structure, IR and NMR spectroscopy studies

NASA Astrophysics Data System (ADS)

Golbedaghi, Reza; Rezaeivala, Majid; Albeheshti, Leila

2014-11-01

Four new [Cd(H2L1)(NO3)]ClO4 (1), [Zn(H2L1)](ClO4)2 (2), [Cd(H2L2)(NO3)]ClO4 (3), and [Zn(H2L2)](ClO4)2 (4), complexes were prepared by the reaction of two new Schiff base ligands and Cd(II) and Zn(II) metal ions in equimolar ratios. The ligands H2L1 and H2L2 were synthesized by reaction of 2-[2-(2-formyl phenoxy)ethoxy]benzaldehyde and/or 2-[2-(3-formyl phenoxy)propoxy]benzaldehyde and ethanol amine and characterized by IR, 1H and 13C NMR spectroscopy. All complexes were characterized by IR, 1H and 13C NMR, COSY, and elemental analysis. Also, the complex 1 was characterized by X-ray in addition to the above methods. The X-ray crystal structure of compound 1 showed that all nitrogen and oxygen atoms of ligand (N2O4) and a molecule of nitrate with two donor oxygen atom have been coordinated to the metal ion and the Cd(II) ion is in an eight-coordinate environment that is best described as a distorted dodecahedron geometry.

Prime Contract Awards Over $25,000 by Major System, Contractor and State Part 2 (AVG NAVY-SMR NAVY)

DTIC Science & Technology

1990-01-01

0 oo0 C) C11 in LA -40w’ I (w -4 N’(. N wO C’-4 4 Go I I I I 5 C- LiCl I m -4 . -40 4 9. C 4,44 44to CL 0 -4 0 -4 Ei EE 0 . Ein % - ) O -Oa W> 444 Pn...3t1, U൰ 4C’J -4)C 0 ) U) 0 0 )M.-4-40-04" I4 Z 7-Ci M’ N N00 C D -4 -4I-4Z4 3:JU I )-( C13- 0 3 )000f 0 ’U) in in i "~ 0 -a < 101ui0 5 -4 O L)- 0 ...M4)u . 0 4W II*-1 4)-- .W0 L-C -4 W I CL. L 0 ) 5 CL a)

Synthesis, structure and study of azo-hydrazone tautomeric equilibrium of 1,3-dimethyl-5-(arylazo)-6-amino-uracil derivatives.

PubMed

Debnath, Diptanu; Roy, Subhadip; Li, Bing-Han; Lin, Chia-Her; Misra, Tarun Kumar

2015-04-05

Azo dyes, 1,3-dimethyl-5-(arylazo)-6-aminouracil (aryl=-C6H5 (1), -p-CH3C6H4 (2), -p-ClC6H4 (3), -p-NO2C6H4 (4)) were prepared and characterized by UV-vis, FT-IR, 1H NMR, 13C NMR spectroscopic techniques and single crystal X-ray crystallographic analysis. In the light of spectroscopic analysis it evidences that of the tautomeric forms, the azo-enamine-keto (A) form is the predominant form in the solid state whereas in different solvents it is the hydrazone-imine-keto (B) form. The study also reveals that the hydrazone-imine-keto (B) form exists in an equilibrium mixture with its anionic form in various organic solvents. The solvatochromic and photophysical properties of the dyes in various solvents with different hydrogen bonding parameter were investigated. The dyes exhibit positive solvatochromic property on moving from polar protic to polar aprotic solvents. They are fluorescent active molecules and exhibit high intense fluorescent peak in some solvents like DMSO and DMF. It has been demonstrated that the anionic form of the hydrazone-imine form is responsible for the high intense fluorescent peak. In addition, the acid-base equilibrium in between neutral and anionic form of hydrazone-imine form in buffer solution of varying pH was investigated and evaluated the pKa values of the dyes by making the use of UV-vis spectroscopic methods. The determined acid dissociation constant (pKa) values increase according to the sequence of 2>1>3>4. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemistry of group 9 dimetallaborane analogues of octaborane(12).

PubMed

Barik, Subrat Kumar; Roy, Dipak Kumar; Ghosh, Sundargopal

2015-01-14

We report the synthesis, isolation and structural characterization of several moderately air stable nido-metallaboranes that represent boron rich open cage systems. The reaction of [Cp*CoCl]2, (Cp* = η(5)-C5Me5), with [BH3·thf] in toluene at ice cold temperature, followed by thermolysis in boiling toluene produced [(Cp*Co)B9H13], 1 [(Cp*Co)2B8H12], 2 and [(Cp*Co)2B6H10] 3. Building upon our earlier reactivity studies on rhodaboranes, we continue to explore the reactivity of dicobalt analogues of octaborane(12) cluster 3 with [Fe2(CO)9] and [Ru3(CO)12] at ambient conditions that yielded novel fused clusters [Fe2(CO)6(Cp*Co)2B6H10], 4 and [Ru4(CO)11(Cp*Co)2B3H3], 5 respectively. In an attempt to synthesize a heterometallic metallaborane compound we performed the reaction of [(Cp*Rh)2B6H10], 6 with [Cp*IrH4] that yielded a Ir-Ir double bonded compound [(Cp*Ir)2H3][B(OH)4], 7. All the new compounds have been characterized by IR, (1)H, (11)B, (13)C NMR spectroscopy, and the molecular structures were unambiguously established by X-ray diffraction analysis.

2-Acylpyrroles as mono-anionic O,N-chelating ligands in silicon coordination chemistry.

PubMed

Kämpfe, Alexander; Brendler, Erica; Kroke, Edwin; Wagler, Jörg

2014-07-21

Kryptopyrrole (2,4-dimethyl-3-ethylpyrrole) was acylated with, for example, benzoyl chloride to afford 2-benzoyl-3,5-dimethyl-4-ethylpyrrole (L(1)H). With SiCl4 this ligand reacts under liberation of HCl and formation of the complex L(1)2SiCl2. In related reactions with HSiCl3 or H2SiCl2, the same chlorosilicon complex is formed under liberation of HCl and H2 or liberation of H2, respectively. The chlorine atoms of L(1)2SiCl2 can be replaced by fluoride and triflate using ZnF2 and Me3Si-OTf, respectively. The use of a supporting base (triethylamine) is required for the complexation of phenyltrichlorosilane and diphenyldichlorosilane. The complexes L(1)2SiCl2, L(1)2SiF2, L(1)2Si(OTf)2, L(1)2SiPhCl, and L(1)2SiPh2 exhibit various configurations of the octahedral silicon coordination spheres (i.e. cis or trans configuration of the monodentate substituents, different orientations of the bidentate chelating ligands relative to each other). Furthermore, cationic silicon complexes L(1)3Si(+) and L(1) SiPh(+) were synthesized by chloride abstraction with GaCl3. In contrast, reaction of L(1)2SiCl2 with a third equivalent of L(1)H in the presence of excess triethylamine produced a charge-neutral hexacoordinate Si complex with a new tetradentate chelating ligand which formed by Si-templated C-C coupling of two ligands L(1). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Decomposition of the polycyclic nitramine explosive, CL-20, by Fe(0).

PubMed

Balakrishnan, Vimal K; Monteil-Rivera, Fanny; Halasz, Annamaria; Corbeanu, Aurelian; Hawari, Jalal

2004-12-15

CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane), C6H6N12O12, is an emerging energetic chemical that may replace RDX, but its degradation pathways are not well-known. In the present study, zerovalent iron was used to degrade CL-20 with the aim of determining its products and degradation pathways. In the absence of O2, CL-20 underwent a rapid decomposition with the concurrent formation of nitrite to ultimately produce nitrous oxide, ammonium, formate, glyoxal, and glycolate. LC/MS (ES-) showed the presence of several key products carrying important information on the initial reactions involved in the degradation of CL-20. For instance, a doubly denitrated intermediate of CL-20 was detected together with the mono- and dinitroso derivatives of the energetic chemical. Two other intermediates with [M-H]- at 392 and 376 Da, matching empirical formulas of C6H7N11O10 and C6H7N11O9, respectively, were detected. Using 15N-labeled CL-20, the two intermediates were tentatively identified as the denitrohydrogenated products of CL-20 and its mononitroso derivative, respectively. The present experimental findings suggest that CL-20 degraded via at least two initial routes: one involving denitration and the second involving sequential reduction of the N-NO2 to the corresponding nitroso (N-NO) derivatives prior to denitration and ring cleavage.

The influence of instrumental line shape degradation on NDACC gas retrievals: total column and profile

NASA Astrophysics Data System (ADS)

Sun, Youwen; Palm, Mathias; Liu, Cheng; Hase, Frank; Griffith, David; Weinzierl, Christine; Petri, Christof; Wang, Wei; Notholt, Justus

2018-05-01

We simulated instrumental line shape (ILS) degradations with respect to typical types of misalignment, and compared their influence on each NDACC (Network for Detection of Atmospheric Composition Change) gas. The sensitivities of the total column, the root mean square (rms) of the fitting residual, the total random uncertainty, the total systematic uncertainty, the total uncertainty, degrees of freedom for signal (DOFs), and the profile with respect to different levels of ILS degradation for all current standard NDACC gases, i.e. O3, HNO3, HCl, HF, ClONO2, CH4, CO, N2O, C2H6, and HCN, were investigated. The influence of an imperfect ILS on NDACC gases' retrieval was assessed, and the consistency under different meteorological conditions and solar zenith angles (SZAs) were examined. The study concluded that the influence of ILS degradation can be approximated by the linear sum of individual modulation efficiency (ME) amplitude influence and phase error (PE) influence. The PE influence is of secondary importance compared with the ME amplitude. Generally, the stratospheric gases are more sensitive to ILS degradation than the tropospheric gases, and the positive ME influence is larger than the negative ME. For a typical ILS degradation (10 %), the total columns of stratospheric gases O3, HNO3, HCl, HF, and ClONO2 changed by 1.9, 0.7, 4, 3, and 23 %, respectively, while the columns of tropospheric gases CH4, CO, N2O, C2H6, and HCN changed by 0.04, 2.1, 0.2, 1.1, and 0.75 %, respectively. In order to suppress the fractional difference in the total column for ClONO2 and other NDACC gases within 10 and 1 %, respectively, the maximum positive ME degradations for O3, HNO3, HCl, HF, ClONO2, CO, C2H6, and HCN should be less than 6, 15, 5, 5, 5, 5, 9, and 13 %, respectively; the maximum negative ME degradations for O3, HCl, and HF should be less than 6, 12, and 12 %, respectively; the influence of ILS degradation on CH4 and N2O can be regarded as being negligible.

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

PubMed

Sagar, Belakavadi K; Harsha, Kachigere B; Yathirajan, Hemmige S; Rangappa, Kanchugarakoppal S; Rathore, Ravindranath S; Glidewell, Christopher

2017-03-01

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Cytotoxicity of ferrocenyl-ethynyl phosphine metal complexes of gold and platinum.

PubMed

Fourie, Eleanor; Erasmus, Elizabeth; Swarts, Jannie C; Jakob, Alexander; Lang, Heinrich; Joone, Gisela K; VAN Rensburg, Constance E J

2011-03-01

Ferrocene derivatives may possess antineoplastic activity. Those with low ferrocenyl reduction potentials often have the highest anticancer activity, as cell components have to oxidise them to the active ferrocenium species before cytotoxicity can be recorded. Some gold(I) complexes also possess anticancer activity. This study examined the cytotoxicity of ferrocenyl-ethynyl and ruthenocenyl-ethynyl complexes of gold and platinum. The results were related to the ease of iron oxidation in the ferrocenyl fragment and compared with the cytotoxicity of cisplatin, [(H(3)N)(2)PtCl(2)] and [Au(PPh(2)CH(2)CH(2)PPh(2))(2)]Cl. Ferrocene-containing gold and platinum complexes of the type Fc-C≡C-PPh(2), 1, and Fc-C≡C-PPh(2)→M with Fc=ferrocenyl (Fe(II)(η(5)-C(5)H(5)) (η(5)-C(5)H(4))), Ph=phenyl (C(6)H(5)) and M=Au-Cl, 2, Au-C≡C-Fc, 3, or Au-C≡C-Rc, 4 (Rc=ruthenocenyl, (Ru(II)(η(5)-C(5)H(5)) (η(5)-C(5)H(4))) and the complex [(Fc-C≡C-PPh(2))(2)PtCl(2)], 5, were investigated. Cytotoxicity tests were determined on the HeLa (human cervix epitheloid) cancer cell line, ATCC CCL-2. Cell survival was measured by means of the colorometric 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide assay. The IC(50) values of compounds 1-4 from four experiments causing 50% cell growth inhibition, ranged between 4.6 and 27 μmol dm(-3). Drug activity was inversely proportional to the sum of all formal reduction potentials, E(o'), of the ferrocenyl groups of the Fc-C≡C-PPh(2) and Fc-C≡C-ligands coordinated to the gold centre. The Fc-C≡C-PPh(2)→Au-Cl complex, compound 2, was most cytotoxic with IC(50)=4.6 μmol dm(-3) , demonstrating the beneficial effect the Cl(-) ion has on the cytotoxicity of these neutral gold complexes. The platinum complex [(Fc-C≡C-PPh(2))(2)PtCl(2)], compound 5, resembling the structure of cisplatin, in principle should exhibit good cytotoxicity, but was not tested due to its total insolubility in any biocompatible medium.

Supramolecular interactions in carboxylate and sulfonate salts of 2,6-diamino-4-chloropyrimidinium.

PubMed

Mohana, Marimuthu; Thomas Muthiah, Packianathan; Butcher, Ray J

2017-07-01

Two new salts, namely 2,6-diamino-4-chloropyrimidinium 2-carboxy-3-nitrobenzoate, C 4 H 6 ClN 4 + ·C 8 H 4 NO 6 - , (I), and 2,6-diamino-4-chloropyrimidinium p-toluenesulfonate monohydrate, C 4 H 6 ClN 4 + ·C 7 H 7 O 3 S - ·H 2 O, (II), have been synthesized and characterized by single-crystal X-ray diffraction. In both crystal structures, the N atom in the 1-position of the pyrimidine ring is protonated. In salt (I), the protonated N atom and the amino group of the pyrimidinium cation interact with the carboxylate group of the anion through N-H...O hydrogen bonds to form a heterosynthon with an R 2 2 (8) ring motif. In hydrated salt (II), the presence of the water molecule prevents the formation of the familiar R 2 2 (8) ring motif. Instead, an expanded ring [i.e. R 3 2 (8)] is formed involving the sulfonate group, the pyrimidinium cation and the water molecule. Both salts form a supramolecular homosynthon [R 2 2 (8) ring motif] through N-H...N hydrogen bonds. The molecular structures are further stabilized by π-π stacking, and C=O...π, C-H...O and C-H...Cl interactions.

Solvation Thermodynamic Properties of Hydrogen Sulfide in [C4mim][PF6], [C4mim][BF4], and [C4mim][Cl] Ionic Liquids, Determined by Molecular Simulations.

PubMed

Sánchez-Badillo, Joel; Gallo, Marco; Alvarado, Sandra; Glossman-Mitnik, Daniel

2015-08-20

Removal of hydrogen sulfide (H2S) and acid gases from natural gas is accomplished by absorption processes using a solvent. The gas solubility in a liquid can be used to measure the degree of removal of the gas and is quantified by the Henry's constant, the free energy of solvation at infinite dilution, or the excess chemical potential. In this work, Henry's constants and thermodynamic properties of solvation of H2S were calculated in three ionic liquids: [C4mim][PF6], [C4mim][BF4], and [C4mim][Cl] ([C4mim], 1-butyl-3-methyl imidazolium). The first step in this work was the evaluation of the force fields for the gas and condensed phases in order to obtain accurate values for the excess chemical potential for H2S on each ionic liquid using free energy perturbation techniques. In the H2S-[C4mim][PF6] and H2S-[C4mim][BF4] systems, the results obtained by molecular simulation agree with the experimental values reported in the literature. However, the solvation free energy calculated for the H2S-[C4mim][Cl] system can be considered predictive because of the lack of experimental data at the simulated conditions. Based on these results, the best solvent for removing H2S is [C4mim][Cl] because it has the highest affinity for this species (lowest value of the Henry's constant). Also, solvation thermodynamic properties such as enthalpy and entropy were calculated in order to evaluate their contribution to the free energy of solvation.

Syntheses, crystal structures and supramolecular topologies of copper(II)-main group metal complexes derived from N,N‧-o-phenylenebis(3-ethoxysalicylaldimine)

NASA Astrophysics Data System (ADS)

Mondal, Suraj; Hazra, Susanta; Sarkar, Sohini; Sasmal, Sujit; Mohanta, Sasankasekhar

2011-10-01

The work in the present investigation reports the syntheses, crystal structures and supramolecular topologies of 11 copper(II)-main group metal ion complexes [Cu IILNa I(NO 3)(H 2O)]·2CH 3CN ( 1), [Cu IILNa I(N 3)(CH 3OH)]·CH 3OH ( 2), [Cu IILNa I(ClO 4)(CH 3CN)]·0.5CH 3CN ( 3), [Cu IILNa I(BF 4)(CH 3OH)]·H 2O ( 4), [{Cu IILNa I(H 2O)} 2(Cu IIL)](BPh 4) 2 ( 5), [Cu IILK I(ClO 4)(CH 3COCH 3)] ( 6), [Cu IILCa II(ClO 4) 2(H 2O)] ( 7), [{Cu IILCa II(NO 3)(μ-NO 3)(H 2O)}(Cu IIL)]·H 2O·CH 3COCH 3 ( 8), [(Cu IIL) 2Ba II(NO 3) 2]·CH 3OH ( 9), [Cu IILPb II(NO 3) 2]·CH 3OH ( 10) and [Cu IILBi III(NO 3) 3]·CH 3COCH 3 ( 11), where H 2L = N, N'- o-phenylenebis(3-ethoxysalicylaldimine). Among these, eight ( 1-4, 6, 7, 10 and 11) are dinuclear compounds, one ( 9) is trinuclear double-decker sandwich compound, one ( 8) is a [2 × 1 + 1 × 1] trimetallic cocrystal of a dinuclear and a mononuclear units and the remaining ( 5) is a [2 × 2 + 1 × 1] pentametallic cocrystal of two dinuclear and one mononuclear units. All the 11 compounds 1-11 contain one or more deprotonated ligand, L 2-, the salen type N 2O 2 compartment of each of which is occupied by a Cu II ion to result in the formation of a [Cu IIL] moiety. On the other hand, the larger and open O(phenoxo) 2O(ethoxy) 2 compartment of the ligand in one or more [Cu IIL] moieties interact (s) with the metal ions Na I ( 1-5)/K I ( 6)/Ca II ( 7 and 8)/Ba II ( 9)/Pb II ( 10)/Bi III ( 11) to produce the title compounds. It has been observed that the neighbouring di/trinuclear units in 1/ 3/ 4/ 6/ 9/ 10/ 11 are self-assembled to one-/two-dimensional topologies as a result of one or more C sbnd H⋯O/O sbnd H⋯O hydrogen bonding interaction (s). Following self-assemblies are observed: one-dimensional in 4, one-dimensional helical in 1, one-dimensional double-chain (ladder) in 3, 6 and 10, two-dimensional in 9 and 11.

2-(1,2,3,4-Tetra-hydro-1-naphth-yl)imidazolium chloride monohydrate.

PubMed

Bruni, Bruno; Bartolucci, Gianluca; Ciattini, Samuele; Coran, Silvia

2010-08-18

In the title compound, C(13)H(15)N(2) (+)·Cl(-)·H(2)O, the ions and water mol-ecules are -connected by N-H⋯Cl, O-H⋯Cl, NH⋯Cl⋯HO, NH⋯Cl⋯HN and OH⋯Cl⋯HO inter-actions, forming discrete D(2) and D(2) (1)(3) chains, C(2) (1)(6) chains and R(4) (2)(8) rings, leading to a neutral two-dimensional network. The crystal structure is further stabilized by π-π stacking inter-actions [centroid-centroid distance = 3.652 (11) Å].

Lubricant Performance and Evaluation.

DTIC Science & Technology

1987-06-01

Robert E. Kauffman * University of Day..on Research InstituteI Dayton, Ohio 4546; Jun 1987 S U- 4BD Interim Technical Report For Period17 June 1985...InI 133 43-.-l 311 u0.C ) 4- ta 0 0)0 m~tO tD r-ww D Chm4- -4 CD ") I-MW--- L)Ci 00 LnCD 0000004.4.(AJC cctO 0~ CO 4 LAU, CL 4) 4i M0 m 0 cmi CA...L)E- CP L) C,1-4 P)1- lz 1 0 "’ dccE-4 C") LA tD wx I (𔃻 :D W wI 363 0 -4 0) %0 0** *A ONV 9) kn k )4) 12LnA 4-4 0 0m - O .Dt-C%0 ~ 0 -0 *-LA .h %D

Thalassospira alkalitolerans sp. nov. and Thalassospira mesophila sp. nov., isolated from a decaying bamboo sunken in the marine environment, and emended description of the genus Thalassospira.

PubMed

Tsubouchi, Taishi; Ohta, Yukari; Haga, Takuma; Usui, Keiko; Shimane, Yasuhiro; Mori, Kozue; Tanizaki, Akiko; Adachi, Akiko; Kobayashi, Kiwa; Yukawa, Kiyotaka; Takagi, Emiko; Tame, Akihiro; Uematsu, Katsuyuki; Maruyama, Tadashi; Hatada, Yuji

2014-01-01

Two marine bacteria, designated strains MBE#61(T) and MBE#74(T), were isolated from a piece of sunken bamboo in the marine environment in Japan. Both of these strains were Gram-stain-negative, but had different cell shapes: MBE#61(T) was spiral, whereas MBE#74(T) was rod-shaped. The temperature, pH and salt concentration ranges for growth of strain MBE#61(T) were 4-38 °C (optimal at 32 °C), pH 4.5-11.0 (optimal at pH 7.0-8.0) and 1-11 % (optimal at 2 %) NaCl, whereas those of strain MBE#74(T) were 4-36 °C (optimal at 30 °C), pH 4.0-10.5 (optimal at pH 7.0-8.0) and 1-12 % (optimal at 4 %) NaCl. Phylogenetic analysis based on partial 16S rRNA gene sequences revealed that both strains belong to the genus Thalassospira within the class Alphaproteobacteria. Similarity between the 16S rRNA gene sequence of strain MBE#61(T) and those of the type strains of species of the genus Thalassospira was 97.5-99.0 %, and that of strain MBE#74(T) was 96.9-98.6 %; these two isolates were most closely related to Thalassospira lucentensis QMT2(T). However, the DNA-DNA hybridization values between T. lucentensis QMT2(T) and strain MBE#61(T) or MBE#74(T) were only 16.0 % and 7.1 %, respectively. The DNA G+C content of strain MBE#61(T) was 54.4 mol%, and that of strain MBE#74(T) was 55.9 mol%. The predominant isoprenoid quinone of the two strains was Q-10 (MBE#61(T), 97.3 %; MBE#74(T), 93.5 %). The major cellular fatty acids of strain MBE#61(T) were C18 : 1ω7c (31.1 %), summed feature 3 comprising C16 : 0ω7c/iso-C15 : 0 2-OH (26.1 %) and C16 : 0 (20.9 %); those of strain MBE#74(T) were C16 : 0 (26.2 %), C17 : 0 cyclo (19.9 %) and C18 : 1ω7c (12.1 %). On the basis of these results, strain MBE#61(T) and strain MBE#74(T) are considered to represent novel species of the genus Thalassospira, for which names Thalassospira alkalitolerans sp. nov. and Thalassospira mesophila sp. nov. are proposed. The type strains are MBE#61(T) ( = JCM 18968(T) = CECT 8273(T)) and MBE#74(T) ( = JCM 18969(T) = CECT 8274(T)), respectively. An emended description of the genus Thalassospira is also proposed.

Synthesis, crystal structures and luminescent properties of two 4 d-4 f Ln-Ag heterometallic coordination polymers based on anion template

NASA Astrophysics Data System (ADS)

Fan, Le-Qing; Chen, Yuan; Wu, Ji-Huai; Huang, Yun-Fang

2011-04-01

Two new 4 d-4 f Ln-Ag heterometallic coordination polymers, {[ Ln3Ag 5(IN) 10(H 2O) 7]·4(ClO 4)·4(H 2O)} n ( Ln=Eu ( 1) and Sm ( 2), HIN=isonicotinic acid), have been synthesized under hydrothermal conditions by reactions of Ln2O 3, AgNO 3, HIN and HClO 4, and characterized by elemental analysis, IR, thermal analysis and single-crystal X-ray diffraction. It is proved that HClO 4 not only adjusts the pH value of the reaction mixture, but also acts as anion template. The structure determination reveals that 1 and 2 are isostructural and feature a novel two-dimensional (2D) layered hetrometallic structure constructed from one-dimensional Ln-carboxylate chains and pillared Ag(IN) 2 units. The 2D layers are further interlinked through Ag⋯Ag and Ag⋯O(ClO 4-) multiple weak interactions, which form a rare Ag-ClO 4 ribbon in lanthanide-transition metal coordination polymers, to give rise to a three-dimensional supramolecular architecture. Moreover, the luminescent properties of these two compounds have also been investigated at room temperature.

Enhanced hydrogen release by catalyzed hydrolysis of sodium borohydride-ammonia borane mixtures: a solution-state 11B NMR study.

PubMed

Hannauer, J; Demirci, U B; Geantet, C; Herrmann, J M; Miele, P

2011-03-07

Hydrolysis of mixtures consisting of sodium borohydride NaBH(4) (SB) and ammonia borane NH(3)BH(3) (AB) was studied in the absence/presence of a Co catalyst. The kinetics of the H(2) evolutions was measured. The reactions were followed in situ by solution-state (11)B NMR and the hydrolysis by-products characterized by NMR, XRD and IR. It is demonstrated that the combination of the two compounds gives a synergetic effect. SB rapidly reduces the Co catalyst precursor and the NH(4)(+) ions from AB contribute in the dispersion of the in situ formed Co nanoparticles. As a result, the kinetics of H(2) evolution is greatly improved. For instance, a hydrogen generation rate of 29.6 L min(-1) g(-1)(Co) was found for a mixture consisting of 81 wt% NH(3)BH(3), 9 wt% NaBH(4) and 10 wt% CoCl(2). By (11)B NMR, it was showed that the reaction mechanisms are quite trivial. As soon as the Co catalyst forms in situ, SB, rather than AB, hydrolyzes until it is totally converted. Then, the overall hydrolysis continues with that of AB. Both reactions follow a bimolecular Langmuir-Hinshelwood mechanism; no reaction intermediates were observed during the process. In fact, SB and AB convert directly into B(OH)(4)(-), which comes in equilibrium with a polyborate compound identified as B(3)O(3)(OH)(4)(-). All of these results are discussed herein.

Identification and Characterization of Natural Sources of Perchlorate

DTIC Science & Technology

2017-01-01

western USA indicating a predominantly natural atmospheric source of ClO4- in all of the lakes. Bomb -pulse 36Cl is largely retained in Lake Superior...from modern (e.g., JYT-1 with 100 percent modern C and post- bomb 3H) to more than 10,000 years (e.g., MW3 with 34 percent modern C and 3H near the...detection limit); however, there is evidence for mixing of old and young water in some cases (MW2 with low 14C and post- bomb 3H) (Table 2.1.4). 22

Laboratory and in-situ reductions of soluble phosphorus in swine waste slurries.

PubMed

Burns, R T; Moody, L B; Walker, F R; Raman

2001-11-01

Laboratory and field experiments were conducted using magnesium chloride (MgCl2) to force the precipitation of struvite (MgNH4PO4 x 6H2O) and reduce the concentration of soluble phosphorus (SP) in swine waste. In laboratory experiments, reductions of SP of 76% (572 to 135 mg P l(-1)) were observed in raw swine manure after addition of magnesium chloride (MgCl2) at a rate calculated to provide a 1.6:1 molar ratio of magnesium (Mg) to total phosphorus. Adjusting the pH of the treated manure to pH 9.0 with sodium hydroxide (NaOH) increased SP reduction to 91% (572 to 50 mg P l(-1)). X-ray diffraction of the precipitate recovered from swine waste slurry treated only with MgCl2 confirmed the presence ofstruvite. The molar N:P:Mg ratio of the recovered precipitate was 1:1.95:0.24, suggesting that compounds in addition to struvite were formed. In a field experiment conducted in a swine manure holding pond, a 90% reduction in SP concentration was observed in approximately 140,000 l of swine manure slurry treated before land application with 2,000 l MgCl2 (64% solution) at ambient slurry temperatures ranging from 5 to 10 degrees C.

Polymer precursors for ceramic matrix composites

NASA Technical Reports Server (NTRS)

Litt, M. H.; Kumar, K.

1986-01-01

The synthesis and characterization of a polycyclohexasilane is reported. Because of its cyclic structure, it is anticipated that this polymer might serve as a precursor to SIC having a high char yield with little rearrangement to form small, volatile cyclic silanes, and, as such, would be of interest as a precursor to SiC composite matrices and fibers, or as a binder in ceramic processing. Several approaches to the synthesis of a bifunctional cyclic monomer were attempted; the most successful of these was metal coupling of PhMeSiCl2 and Me2SiCl2. The procedure gives six-membered ring compounds with all degrees of phenyl substitution, from none to hexaphenyl. The compounds with from 0-2 groups were isolated and characterized. The fraction with degree of phenyl substitution equal to 2, a mixture of cis and trans 1,2-; 1,3-; and 1,4 isomers, was isolated in 32 percent yield. Pure 1,4 diphenyldecamethylcyclohexasilane was isolated from the mixed diphenyl compounds and characterized. Diphenyldecamethylcyclohexasilanes were dephenylated to dichlorodecamethylcyclohexasilanes by treating with H2SO4.NH4Cl in benzene. The latter were purified and polymerized by reacting with sodium in toluene. The polymers were characterized by HPGPC, elemental analysis, proton NMR, and IR. Thermogravimetric analyses were carried out on the polymers. As the yield of residual SiC was low, polymers were heat treated to increase the residual char yield. As high as 51.52 percent residual char yield was obtained in one case.

Reaction of tin(iv) phthalocyanine dichloride with decamethylmetallocenes (M = CrII and CoII). Strong magnetic coupling of spins in (Cp*2Co+){SnIVCl2(Pc˙3-)}˙-·2C6H4Cl2.

PubMed

Konarev, Dmitri V; Troyanov, Sergey I; Shestakov, Alexander F; Yudanova, Evgeniya I; Otsuka, Akihiro; Yamochi, Hideki; Kitagawa, Hiroshi; Lyubovskaya, Rimma N

2018-01-23

The reaction of tin(iv) phthalocyanine dichloride {Sn IV Cl 2 (Pc 2- )} with decamethylmetallocenes (Cp* 2 M, M = Co, Cr) has been studied. Decamethylcobaltocene reduces Sn IV Cl 2 (Pc 2- ) to form the (Cp* 2 Co + ){Sn IV Cl 2 (Pc˙ 3- )}˙ - ·2C 6 H 4 Cl 2 (1) complex. The negative charge of {Sn IV Cl 2 (Pc˙ 3- )}˙ - is delocalized over the Pc macrocycle providing the alternation of the C-N(imine) bonds, the appearance of new bands in the NIR range and a strong blue shift of both the Soret and Q-bands in the spectrum of 1. The magnetic moment of 1 is equal to 1.68μ B at 300 K, indicating the contribution of one S = 1/2 spin of the Pc˙ 3- macrocycles. These macrocycles form closely packed double stacks in 1 with effective π-π interactions providing strong antiferromagnetic coupling of spins at a Weiss temperature of -80 K. Decamethylchromocene initially also reduces Sn IV Cl 2 (Pc 2- ) to form the [(Cp* 2 Cr + ){Sn VI Cl 2 (Pc˙ 3- )}˙ - complex but further reaction between the ions is observed. This reaction is accompanied by the substitution of one Cp* ligand of Cp* 2 Cr by chloride anions originating from {Sn IV Cl 2 (Pc˙ 3- )}˙ - to form the complex {(Cp*CrCl 2 )(Sn IV (μ-Cl)(Pc 2- ))}·C 6 H 4 Cl 2 (2) in which the (Cp*CrCl 2 ) and {Sn IV (Pc 2- )} species are bonded through the μ-bridged Cl - anion. According to the DFT calculations, this reaction proceeds via an intermediate [(Cp* 2 CrCl)(SnClPc)] complex.

Temperature-Dependent Kinetics Studies of the Reactions Br((sup 2)P(sub 3/2)) + CH3SCH3 reversible reaction CH3SCH2 + HBr. Heat of Formation of the CH3SCH2 Radical

NASA Technical Reports Server (NTRS)

Jefferson, A.; Nicovich, J. M.; Wine, P. H.

1997-01-01

Time-resolved resonance fluorescence detection of Br((sup 2)P(sub 3/2)) atom disappearance or appearance 266 nm laser flash photolysis of CF2Br2/CH3SCH3/H2/N2 and Cl2CO/CH2SCH3/HBr/H2/N2 mixtures has been employed to study the kinetics of the reactions Br((sup 2)P(sub 3/2)) + CH3SCH3 reversible reaction HBr + CH3SCH2 (1,-1) as a function of temperature over the range 386-604 K. Arrhenius expressions in units of cu cm/molecule which describe the results are k3= (9.0 +/- 2.9) x 10 (exp -11) exp[(-2386 +/- 151)/T]; errors are 2 sigma and represent precision only. To our knowledge, these are the first kinetic data reported for each of the two reactions studied. Second and third law analyses of the equilibrium data for reactions 1 and -1 have been employed to obtain the following enthalpies of reaction in units of kcal/mol: Delta-H(298) = 6.11 +/- 1.37 and Delta-H(0) = 5.37 +/- 1.38. Combining the above enthalpies of reaction with the well-known heats of formation of Br, HBr, CH3SCH3 gives the following heats of formation of the CH3SCH2 radical in units of kcal/mol: Delta-H(sub(f,298)) = 32.7 +/- 1.4 and Delta-H(sub (f,0)) = 35.3 +/- 1.4; errors are 2 sigma and represent estimates of absolute accuracy. The C-H bond dissociation energy in CH3SCH3 obtained from our data, 93.7 +/- 1.4 kcal/mol at 298 K and 92.0 +/- 1.4 kcal at 0 k, agrees well with a recent molecular beam photofragmentaion study but is 3 kcal/mol lower than the value obtained from an iodination kinetics study.

1-(3,3-Dichloro-all-yloxy)-4-methyl-2-nitro-benzene.

PubMed

Ren, Dong-Mei

2012-06-01

In the title compound, C(10)H(9)Cl(2)NO(3), the dihedral angle between the benzene ring and the plane of the nitro group is 39.1 (1)°, while that between the benzene ring and the plane through the three C and two Cl atoms of the dichloro-all-yloxy unit is 40.1 (1)°. In the crystal, C-H⋯O hydrogen bonds to the nitro groups form chains along the b axis. These chains are linked by inversion-related pairs of Cl⋯O inter-actions at a distance of 3.060 (3) Å, forming sheets approximately parallel to [-201] and generating R(2) (2)(18) rings. π-π contacts between benzene rings in adjacent sheets, with centroid-centroid distances of 3.671 (2) Å, stack mol-ecules along c.

Complexes of dichloro[2-(dimethylaminomethyl)phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], with formylferrocene thiosemicarbazones: synthesis, structure and cytotoxicity.

PubMed

Casas, José S; Castaño, María V; Cifuentes, María C; García-Monteagudo, Juán C; Sánchez, Agustín; Sordo, José; Abram, Ulrich

2004-06-01

Dichloro[2-(dimethylaminomethyl)phenyl- phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], reacts with the formylferrocene thiosemicarbazones derived from 4-methyl-, 4-phenyl-, 4-ethyl- and 4,4-dimethyl-3-thiosemicarbazides, HFcTSC, to give complexes of general formula [Au(Hdamp-1C)Cl(FcTSC)]Cl. These complexes were isolated and characterized by elemental analysis, mass spectrometry and IR, 1H NMR and (13)C NMR spectroscopy. In some cases, cyclic voltammetric studies were carried out and these showed that the complexation of gold affects the redox behaviour of the ferrocene unit. The in vitro antitumor activity against the HeLa cell line was also determined for the more soluble complexes. The IC(50) values were found to be higher than that of cisplatin but the maximum antiproliferative activity was similar.

Sensitivity of chloride efflux vs. transepithelial measurements in mixed CF and normal airway epithelial cell populations.

PubMed

Illek, Beate; Lei, Dachuan; Fischer, Horst; Gruenert, Dieter C

2010-01-01

While the Cl(-) efflux assays are relatively straightforward, their ability to assess the efficacy of phenotypic correction in cystic fibrosis (CF) tissue or cells may be limited. Accurate assessment of therapeutic efficacy, i.e., correlating wild type CF transmembrane conductance regulator (CFTR) levels with phenotypic correction in tissue or individual cells, requires a sensitive assay. Radioactive chloride ((36)Cl) efflux was compared to Ussing chamber analysis for measuring cAMP-dependent Cl(-) transport in mixtures of human normal (16HBE14o-) and cystic fibrosis (CF) (CFTE29o- or CFBE41o-, respectively) airway epithelial cells. Cell mixtures with decreasing amounts of 16HBE14o- cells were evaluated. Efflux and Ussing chamber studies on mixed populations of normal and CF airway epithelial cells showed that, as the number of CF cells within the population was progressively increased, the cAMP-dependent Cl(-) decreased. The (36)Cl efflux assay was effective for measuring Cl(-) transport when ≥ 25% of the cells were normal. If < 25% of the cells were phenotypically wild-type (wt), the (36)Cl efflux assay was no longer reliable. Polarized CFBE41o- cells, also homozygous for the ΔF508 mutation, were used in the Ussing chamber studies. Ussing analysis detected cAMP-dependent Cl(-) currents in mixtures with ≥1% wild-type cells indicating that Ussing analysis is more sensitive than (36)Cl efflux analysis for detection of functional CFTR. Assessment of CFTR function by Ussing analysis is more sensitive than (36)Cl efflux analysis. Ussing analysis indicates that cell mixtures containing 10% 16HBE14o- cells showed 40-50% of normal cAMP-dependent Cl(-) transport that drops off exponentially between 10-1% wild-type cells. Copyright © 2010 S. Karger AG, Basel.

Word Frequency Analysis. MOS: 62J. Skill Levels 1 & 2.

DTIC Science & Technology

1981-05-01

WCRDI COUNT2 W OR u, CO UIT 3 WORD 3 COUNT’. kCRD4 I CELL 9 CLNTER I CERERLINE t CENTRALLY 2 C [JTP I FGAL 2 CZRT..IN I CESSIVE 46 LFI’ 14 C H%1% ~ 4...4 .4* 4 AD ,G4 ANGLI 4 fC S 0A 4 r. 5 54b d204 4 BE- J 4OCK4 ECAGNE 4 TTA .(.KFTS 4 B𔃻E.KER 4 44 CC!’PPCT 4 13FL*.~If 4 CCLC CTwV7CCC~L< EL4 CO 4 CE...t CI RE I CARTcUL I CAR7~ I 3 CARRY I CAL 7I C!! 11 E t C., TFPS I CA~TCH I C4TEO I co usIN Kr I CL TC1 I CELL 1CTNlERL!NEz I ’ENI P.LIY Ic3VEI

Structural, crystal structure, Hirshfeld surface analysis and physicochemical studies of a new chlorocadmate template by 1-(2-hydroxyethyl)piperazine

NASA Astrophysics Data System (ADS)

Soudani, S.; Jeanneau, E.; Jelsch, C.; Lefebvre, F.; Ben Nasr, C.

2016-11-01

The synthesis, crystal structure and spectroscopic characterization of a new chlorocadmate template by the 1-(2-hydroxyethyl)piperazine ligand are reported. In the atomic arrangement, the CdCl5O entities are deployed in corrugated rows along the a-axis at y = 1/4 and y = 3/4 to form layers parallel to the (a,b) plane. In these crystals, piperazinediium cations are in a chair conformation and are inserted between these layers through Nsbnd H⋯Cl, Csbnd H⋯Cl, Osbnd H⋯Cl and Nsbnd H⋯O hydrogen bonds to form infinite three-dimensional network. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that H⋯Cl and Csbnd H⋯Hsbnd C intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The crystal contacts enrichments reveals that, the Cd++ … Cl- salt bridges, the Cd⋯O complexation and Osbnd H⋯Cl- and Nsbnd H⋯Cl-strong H-bonds are the driving forces in the packing formation. The presence of twelve independent chloride anions and four organic cation in the asymmetric unit allowed comparing their contact propensities. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. Additional characterization of this compound has also been performed by IR spectroscopy.

White Light Emission from Planar Remote Phosphor Based on NHC Cycloplatinated Complexes.

PubMed

Fuertes, Sara; Chueca, Andrés J; Perálvarez, Mariano; Borja, Pilar; Torrell, Marc; Carreras, Josep; Sicilia, Violeta

2016-06-29

We report on the generation of bright white luminescence through solid-state illumination of remote phosphors based on novel cycloplatinated N-heterocyclic carbene (NHC) compounds. Following a stepwise protocol we got the new NHC compound [{Pt(μ-Cl)(C(∧)C*)}2] (4) (HC(∧)C*-κC* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene), which was used together with the related ones 4a (HC(∧)C*-κC*= 1-(4-cyanophenyl)-3-methyl-1H-imidazol-2-ylidene) and 4b (HC(∧)C*-κC*= 3-methyl-1-(naphthalen-2-yl)-1H-imidazol-2-ylidene) as starting materials for the synthesis of the new ionic derivatives [Pt(R-C(∧)C*) (CNR')2]PF6 (R = -COOEt, R' = t-Bu (5), Xyl (6); R = -CN, R' = t-Bu (7), Xyl (8); R(∧)C = Naph, R' = t-Bu (9), Xyl (10)). The X-ray structures of 6 and 8-10 have been determined. The photophysical properties of these cationic compounds have been studied and supported by the time-dependent-density functional theory (TD-DFT) calculations. The compounds 5, 8, and 9 have been revealed as the most efficient emitters in the solid state with quantum yields of 41%, 21%, and 40%, respectively. White-light remote-phosphors have been prepared just by stacking different combinations of these compounds and [Pt(bzq) (CN) (CN(t)Bu)] (R1) as blue (5, 8), yellow (9), and red (R1) components onto the same substrate. The CCT (correlated color temperature) and the CRI (color rendering index) of the emitted white-light have been tuned by accurately controlling the individual contributions.

Reversible five-coordinate ⇄ six-coordinate transformation in cobalt(II) complexes

NASA Astrophysics Data System (ADS)

Xiao, Linda; Bhadbhade, Mohan; Baker, Anthony T.

2018-04-01

The heterocyclic ligands 2,6-bis(pyrazol-1-yl)pyridine (L1) and 2,6-bis(benzimidazol-2-yl)pyridine (L2) and their cobalt(II) complexes were synthesized. The blue five-coordinate complex [Co(L1)Cl2] isolated initially from the reaction mixture rapidly absorbed water vapour from the atmosphere to yield the pink six-coordinate complex [Co(L1)(H2O)3]Cl2. This change is reversible upon desiccation or transferring [Co(L1)(H2O)3]Cl2 into acetonitrile. The five coordinate complex [Co(L2)Cl2], however, remains stable under similar conditions. The structures of the complexes [Co(L1)Cl2], [Co(L1)(H2O)3]Cl2 and [Co(L2)Cl2] have been determined by x-ray crystallography. The magnetic susceptibilities and the electronic spectra for [Co(L1)Cl2], [Co(L2)Cl2] and [Co(L1)(H2O)3]Cl2 are presented.

Molecular Structures, Vibrational Spectroscopy, and Normal-Mode Analysis of M(2)(C&tbd1;CR)(4)(PMe(3))(4) Dimetallatetraynes. Observation of Strongly Mixed Metal-Metal and Metal-Ligand Vibrational Modes.

PubMed

John, Kevin D.; Miskowski, Vincent M.; Vance, Michael A.; Dallinger, Richard F.; Wang, Louis C.; Geib, Steven J.; Hopkins, Michael D.

1998-12-28

The nature of the skeletal vibrational modes of complexes of the type M(2)(C&tbd1;CR)(4)(PMe(3))(4) (M = Mo, W; R = H, Me, Bu(t)(), SiMe(3)) has been deduced. Metrical data from X-ray crystallographic studies of Mo(2)(C&tbd1;CR)(4)(PMe(3))(4) (R = Me, Bu(t)(), SiMe(3)) and W(2)(C&tbd1;CMe)(4)(PMe(3))(4) reveal that the core bond distances and angles are within normal ranges and do not differ in a statistically significant way as a function of the alkynyl substituent, indicating that their associated force constants should be similarly invariant among these compounds. The crystal structures of Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) and Mo(2)(C&tbd1;CBu(t)())(4)(PMe(3))(4) are complicated by 3-fold disorder of the Mo(2) unit within apparently ordered ligand arrays. Resonance-Raman spectra ((1)(delta-->delta) excitation, THF solution) of Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) and its isotopomers (PMe(3)-d(9), C&tbd1;CSiMe(3)-d(9), (13)C&tbd1;(13)CSiMe(3)) exhibit resonance-enhanced bands due to a(1)-symmetry fundamentals (nu(a) = 362, nu(b) = 397, nu(c) = 254 cm(-)(1) for the natural-abundance complex) and their overtones and combinations. The frequencies and relative intensities of the fundamentals are highly sensitive to isotopic substitution of the C&tbd1;CSiMe(3) ligands, but are insensitive to deuteration of the PMe(3) ligands. Nonresonance-Raman spectra (FT-Raman, 1064 nm excitation, crystalline samples) for the Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) compounds and for Mo(2)(C&tbd1;CR)(4)(PMe(3))(4) (R = H, D, Me, Bu(t)(), SiMe(3)) and W(2)(C&tbd1;CMe)(4)(PMe(3))(4) exhibit nu(a), nu(b), and nu(c) and numerous bands due to alkynyl- and phosphine-localized modes, the latter of which are assigned by comparisons to FT-Raman spectra of Mo(2)X(4)L(4) (X = Cl, Br, I; L = PMe(3), PMe(3)-d(9))(4) and Mo(2)Cl(4)(AsMe(3))(4). Valence force-field normal-coordinate calculations on the model compound Mo(2)(C&tbd1;CH)(4)P(4), using core force constants transferred from a calculation on Mo(2)Cl(4)P(4), show that nu(a), nu(b), and nu(c) arise from modes of strongly mixed nu(Mo(2)), nu(MoC), and lambda(MoCC) character. The relative intensities of the resonance-Raman bands due to nu(a), nu(b), and nu(c) reflect, at least in part, their nu(M(2)) character. In contrast, the force field shows that mixing of nu(M(2)) and nu(C&tbd1;C) is negligible. The three-mode mixing is expected to be a general feature for quadruply bonded complexes with unsaturated ligands.

Formation and infrared absorption of protonated naphthalenes (1-C10H9+ and 2-C10H9+) and their neutral counterparts in solid para-hydrogen.

PubMed

Bahou, Mohammed; Wu, Yu-Jong; Lee, Yuan-Pern

2013-02-14

Protonated naphthalene (C(10)H(9)(+)) and its neutral counterparts (hydronaphthyl radicals, C(10)H(9)) are important intermediates in the reactions of aromatic compounds and in understanding the unidentified infrared (IR) emissions from interstellar media. We report the IR spectra of 1-C(10)H(9)(+), 2-C(10)H(9)(+), 1-C(10)H(9), and 2-C(10)H(9) trapped in solid para-hydrogen (p-H(2)); the latter three are new. These species were produced upon electron bombardment of a mixture of naphthalene (C(10)H(8)) and p-H(2) during matrix deposition. The intensities of IR features of 1-C(10)H(9)(+) decreased after the matrix was maintained in darkness for 19 h, whereas those of 1-C(10)H(9) and 2-C(10)H(9) increased. Irradiation of this matrix sample with light at 365 nm diminished lines of 1-C(10)H(9)(+) and 2-C(10)H(9) and enhanced lines of 1-C(10)H(9) and 2-C(10)H(9)(+); the latter species was unstable and converted to 1-C(10)H(9)(+) in less than 30 min and 2-C(10)H(9) was converted to 1-C(10)H(9) at 365 nm. Observed wavenumbers and relative intensities of these species agree satisfactorily with the anharmonic vibrational wavenumbers and IR intensities predicted with the B3PW91/6-311++G(2d,2p) method. Compared with spectra recorded previously with IR photodissociation of Ar-tagged C(10)H(9)(+) or IR multiphoton dissociation of C(10)H(9)(+), our method has the advantages of producing high-resolution IR spectra with a wide spectral coverage, true IR intensity and excellent ratio of signal to noise; both protonated species and their neutral counterparts are produced with little interference from other fragments. With these advantages, the IR spectra of 1-C(10)H(9)(+), 2-C(10)H(9)(+), 1-C(10)H(9), and 2-C(10)H(9) are here clearly characterized.

Neurobiology: Sixth Meeting of the European Society for Neurochemistry

DTIC Science & Technology

1986-11-13

4 (NTD Report C88 DTX NourobWoI~y:, Sixth Meeting o0’ th* BUYopen ’Socety for Neurochemistry Clare ff Zaamely-Neureth Noviember 13, 1 M cý-ji)3 C) I9...8217 A pprn)ýed fof publxc ekricfa. di’.rihutu- m unlimited U.S. Office of Naval Research, London UNTCLASSI1FI ED 12CLOTM CL SWIFCATIOM OF TWiS PAG...OKLASSWICAtIO100 IOO~sMADC6d SOO0W 4, MINORAMIG OGMEAAZATION OMPOSIT MJiR 5 hOWO~nM ONGAMIZATI( M MPORT MUNUUSM ’k C-8-86 G. MA* M 0W Pf 90MANOG OOGAkUAT1ON 4b

Effect of 1-aminocyclopropane-1-carboxylic acid on the production of ethylene in senescing flowers of Ipomoea tricolor Cav

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konze, J.R.; Jones, J.F.; Boller, T.

1980-10-01

Application of 1-aminocyclopropane-1-carboxylic acid (ACC) to rib segments excised from flowers of Ipomoea tricolor Cav. resulted in the formation of C/sub 2/H/sub 4/ in greater quantities than produced under natural conditions. The ability of ACC to enhance C/sub 2/H/sub 4/ production was independent of the physiological age of the tissue and its capacity to synthesize C/sub 2/H/sub 4/ without applied ACC. When ACC was fed to rib segments that had been treated with (/sup 14/C)methionine, incorporation of radioactivity into C/sub 2/H/sub 4/ was reduced by 80%. Aminoethoxyvinylglycine and aminooxyacetic acid inhibited C/sub 2/H/sub 4/ production in rib segments of I.more » tricolor but had no effect on ACC-enhanced C/sub 2/H/sub 4/ production. Protoplasts obtained from flower tissue of I. tricolor did not form C/sub 2/H/sub 4/, even when incubated with methionine or selenomethionine. They produced C/sub 2/H/sub 4/ upon incubation with ACC, however. ACC-dependent C/sub 2/H/sub 4/ production in protoplasts was inhibited by n-propyl gallate, AgCl, CoCl/sub 2/, KCN, Na/sub 2/S, and NaN/sub 3/. ACC-dependent C/sub 2/H/sub 4/ synthesis in rib segments and protoplasts was dependent on O/sub 2/, the K/sub m/ for O/sub 2/ being 1.0 to 1.4% (v/v). These results confirm the following pathway for C/sub 2/H/sub 4/ biosynthesis in I. tricolor: methionine (selenomethionine) ..-->..S-adenosylmethionine (selenoadenosylmethionine) ..-->.. ACC ..-->.. C/sub 2/H/sub 4/.« less

Dechlorination and chlorine rearrangement of 1,2,5,5,6,9,10-heptachlorodecane mediated by the whole pumpkin seedlings.

PubMed

Li, Yanlin; Hou, Xingwang; Yu, Miao; Zhou, Qunfang; Liu, Jiyan; Schnoor, Jerald L; Jiang, Guibin

2017-05-01

Short chain chlorinated paraffins (SCCPs) are ubiquitously present as persistent organic pollutants in the environment. However, little information on the interaction of SCCPs with plants is currently available. In this work, young pumpkin plants (Cucurbita maxima × C. Moschata) were hydroponically exposed to the congener of chlorinated decane, 1,2,5,5,6,9,10-heptachlorodecane (1,2,5,5,6,9,10-HepCD), to investigate the uptake, translocation and transformation of chlorinated decanes in the intact plants. It was found that parent HepCD was taken up by the pumpkin roots, translocated from root to shoots, and phytovolatilized from pumpkin plants to air via the plant transpiration flux. Our data suggested that dechlorination of 1,2,5,5,6,9,10-HepCD to lower chlorinated decanes and rearrangement of chlorine atoms in the molecule were all mediated by the whole pumpkin seedlings. Chlorinated decanes were found in the shoots and roots of blank controls, indicating that chlorinated decanes in the air could be absorbed by leaves and translocated from shoots to roots. Lower chlorinated congeners (C 10 H 17 Cl 5 ) tended to detain in air compared to higher chlorinated congeners (C 10 H 16 Cl 6 and other C 10 H 15 Cl 7 ). Potential transformation pathway and behavior of 1,2,5,5,6,9,10-HepCD in pumpkin were proposed based on these experiments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Calculating Toxic Corridors. Revision

DTIC Science & Technology

1989-04-01

16 Table 9 Chlorine Pentafluoride 1CL ........... ................... .. 17 Table 10 Chlorine Trifluoride TCL...60-min EEL: 3.0 ppm 31 Chlorine Pentafluoride 130.445 0.3 4.64 1.5 1(T) 2.03 Mone - (T) - Tentative Chlorine Trifluoride 92.448 0.63 3.88 3.01 1.70...CIF 5 770.4 Chlorine Trifluoride 26.6 1,B33.410 54.141 80 92.448 CIF.3 247.2 Diborane 16.859 B2 H Ethylene- Oxide 27.0 f 1,860.98 54.96 80 44.054 C

Production, characterization, and immobilization of partially purified surfactant-detergent and alkali-thermostable protease from newly isolated Aeromonas caviae.

PubMed

Datta, Sumitra; Menon, Gopalakrishnan; Varughese, Bincy

2017-04-21

Proteolytic Aeromonas caviae P-1-1 growing at wide-ranging pH (7.0-11.0) and moderate salinity (0-5% NaCl) was isolated from cattle shed of Thanjavur, India. It produced lipase, gelatinase, and polyhydroxybutyrate. Different culture conditions, incubation time, carbon and nitrogen sources, vitamins, amino acids, surfactants, and metal ions for optimal growth and protease production of P-1-1 were examined. Maximum protease (0.128 U/mL) production was achieved with 1% fructose, 1% yeast extract, 0.1% ammonium sulfate, 3% NaCl, 0.1% CaCl 2  · 2H 2 O, 1% glycine, 0.1% vitamin E, and 0.1% Tween-40 at pH 8.0 after 42 hr of incubation at 37°C. It was active over broad range of pH (7.0-12.0), temperature (15-100°C), and salinity (0-9% NaCl) with optima at pH 10.0, 55°C, and 3% NaCl. It retained 65 and 48% activities at pH 12.0 and 100°C, respectively. Partially purified protease was highly stable (100%) within pH range 7.0-12.0 and salinities of 0-5% NaCl for 48 hr. Cu 2+ , Mn 2+ , Co 2+ , and Ca 2+ did not inhibit its activity. Its stability at extreme pHs, temperatures, and in the presence of surfactants and commercial detergents suggests its possible application in laundry detergents. Partially purified protease was immobilized and reused. This is the first report of alkali-thermotolerant, surfactant-detergent-stable partially purified extracellular protease from A. caviae.

Legubicin, a Tumor-Activated Prodrug for Breast Cancer Therapy

DTIC Science & Technology

2007-04-01

carcinomas, leukemias, lymphomas, melanomas, fibrosarcomas , neuroblastoma, and the like. The cancer can, for example, be autoimmune deficiency syndrome...their analogs. (a) 4-Nitrophenyl chloroformate, Py, CH2Cl2, 0°C; (b) (i) OsO4 ( cat ), NMO, citric acid, CH2Cl2-H2O (10:1), RT, (ii) NaIO4, THF- H2O (1:1

Lubiprostone activates CFTR, but not ClC-2, via the prostaglandin receptor (EP(4)).

PubMed

Norimatsu, Yohei; Moran, Aurelia R; MacDonald, Kelvin D

2012-09-28

The goal of this study was to determine the mechanism of lubiprostone activation of epithelial chloride transport. Lubiprostone is a bicyclic fatty acid approved for the treatment of constipation [1]. There is uncertainty, however, as to how lubiprostone increases epithelial chloride transport. Direct stimulation of ClC-2 and CFTR chloride channels as well as stimulation of these channels via the EP(4) receptor has been described [2-5]. To better define this mechanism, two-electrode voltage clamp was used to assay Xenopus oocytes expressing ClC-2, with or without co-expression of the EP(4) receptor or β adrenergic receptor (βAR), for changes in conductance elicited by lubiprostone. Oocytes co-expressing CFTR and either βAR or the EP(4) receptor were also studied. In oocytes co-expressing ClC-2 and βAR conductance was stimulated by hyperpolarization and acidic pH (pH = 6), but there was no response to the β adrenergic agonist, isoproterenol. Oocytes expressing ClC-2 only or co-expressing ClC-2 and EP(4) did not respond to the presence of 0.1, 1, or 10 μM lubiprostone in the superperfusate. Oocytes co-expressing CFTR and βAR did not respond to hyperpolarization, acidic pH, or 1 μM lubiprostone. However, conductance was elevated by isoproterenol and inhibited by CFTR(inh)172. Co-expression of CFTR and EP(4) resulted in lubiprostone-stimulated conductance, which was also sensitive to CFTR(inh)172. The EC(50) for lubiprostone mediated CFTR activation was ~10 nM. These results demonstrate no direct action of lubiprostone on either ClC-2 or CFTR channels expressed in oocytes. However, the results confirm that CFTR can be activated by lubiprostone via the EP(4) receptor in oocytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Efficacy of gaseous chlorine dioxide as a sanitizer for killing Salmonella, yeasts, and molds on blueberries, strawberries, and raspberries.

PubMed

Sy, Kaye V; McWatters, Kay H; Beuchat, Larry R

2005-06-01

Gaseous chlorine dioxide (ClO2) was tested for its effectiveness in killing Salmonella, yeasts, and molds on blueberries, strawberries, and red raspberries. An inoculum (100 microl, 6.0 to 6.8 log CFU/g of fruit) that contained five serotypes of Salmonella enterica was deposited on the skin, calyx tissue, or stem scar tissue of blueberries, skin or stem scar tissue of strawberries, and skin of red raspberries, dried for 2 h at 22 degrees C, then held for 20 h at 4 degrees C and 2 h at 22 degrees C before treatment. Sachets that contained reactant chemicals were formulated to release gaseous ClO2 at concentrations of 4.1, 6.2, and 8.0 mg/ liter of air within treatment times of 30, 60, and 120 min, respectively, at 23 +/- 1 degrees C. Lethality of ClO2 to Salmonella, yeasts, and molds was measured when fruits were in an atmosphere that contained 75 to 90% relative humidity. Treatment with 8.0 mg/liter of ClO2 significantly (alpha = 0.05) reduced the population of Salmonella on blueberries by 2.4 to 3.7 log CFU/g. Lethality was higher to cells in inoculum placed on the skin compared with the stem scar tissue. Populations of Salmonella on strawberries treated with 8.0 mg/liter of ClO2 were reduced by 3.8 to 4.4 log CFU/g; a significant reduction of 1.5 log CFU/g of raspberries was achieved. Treatment with 4.1 to 8.0 mg/liter of ClO2 caused reductions in populations of yeast and molds on blueberries, strawberries, and raspberries of 1.4 to 2.5, 1.4 to 4.2, and 2.6 to 3.0 log CFU/g, respectively. Treatment with 4.1 mg/liter of ClO2 did not markedly affect the sensory quality of fruits stored for up to 10 days at 8 degrees C. Results indicate that gaseous ClO2 has promise as a sanitizer for small fruits.

Gold(I) and Gold(III) Complexes of Cyclic (Alkyl)(amino)carbenes

PubMed Central

2016-01-01

The chemistry of Au(I) complexes with two types of cyclic (alkyl)(amino)carbene (CAAC) ligands has been explored, using the sterically less demanding dimethyl derivative Me2CAAC and the 2-adamantyl ligand AdCAAC. The conversion of (AdCAAC)AuCl into (AdCAAC)AuOH by treatment with KOH is significantly accelerated by the addition of tBuOH. (AdCAAC)AuOH is a convenient starting material for the high-yield syntheses of (AdCAAC)AuX complexes by acid/base and C–H activation reactions (X = OAryl, CF3CO2, N(Tf)2, C2Ph, C6F5, C6HF4, C6H2F3, CH2C(O)C6H4OMe, CH(Ph)C(O)Ph, CH2SO2Ph), while the cationic complexes [(AdCAAC)AuL]+ (L = CO, CNtBu) and (AdCAAC)AuCN were obtained by chloride substitution from (AdCAAC)AuCl. The reactivity toward variously substituted fluoroarenes suggests that (AdCAAC)AuOH is able to react with C–H bonds with pKa values lower than about 31.5. This, together with the spectroscopic data, confirm the somewhat stronger electron-donor properties of CAAC ligands in comparison to imidazolylidene-type N-heterocyclic carbenes (NHCs). In spite of this, the oxidation of Me2CAAC and AdCAAC gold compounds is much less facile. Oxidations proceed with C–Au cleavage by halogens unless light is strictly excluded. The oxidation of (AdCAAC)AuCl with PhICl2 in the dark gives near-quantitative yields of (AdCAAC)AuCl3, while [Au(Me2CAAC)2]Cl leads to trans-[AuCl2(Me2CAAC)2]Cl. In contrast to the chemistry of imidazolylidene-type gold NHC complexes, oxidation products containing Au–Br or Au–I bonds could not be obtained; whereas the reaction with CsBr3 cleaves the Au–C bond to give mixtures of [AdCAAC-Br]+[AuBr2]− and [(AdCAAC-Br)]+ [AuBr4]−, the oxidation of (AdCAAC)AuI with I2 leads to the adduct (AdCAAC)AuI·I2. Irrespective of the steric demands of the CAAC ligands, their gold complexes proved more resistant to oxidation and more prone to halogen cleavage of the Au–C bonds than gold(I) complexes of imidazole-based NHC ligands. PMID:26146436

6-Oxocytidine a novel protonated C-base analogue for stable triple helix formation.

PubMed Central

Berressem, R; Engels, J W

1995-01-01

2'-O-Methyl-3'-O-phosphoramidite building blocks of 6-oxocytidine 6 and its 5-methyl derivative 7, respectively, were synthesized and incorporated via phosphoramidite chemistry in 15 mer oligodeoxynucleotides [d(T72T7), S2; d(T73T7), S3] to obtain potential Py.Pu.Py triplex forming homopyrimidine strands. UV thermal denaturation studies and CD spectroscopy of 1:1 mixtures of these oligomers and a 21 mer target duplex [d(C3A7GA7C3)-d(G3T7CT7G3), D1] with a complementary purine tract showed a nearly pH-independent (6.0-8.0) triple helix formation with melting temperatures of 21-19 degrees C and 18.5-17.5 degrees C, respectively (buffer system: 50 mM sodium cacodylate, 100 mM NaCl, 20 mM MgCl2). In contrast, with the corresponding 15mer deoxy-C-containing oligonucleotide [d(T(7)1T7), S1] triplex formation was observed only below pH 6.6. Specificity for the recognition of Watson-Crick GC-base pairs was observed by pairing the modified C-bases of the 15mers with all other possible Watson-Crick-base compositions in the target duplex [d(C3A7XA7C3)-d(G3T7YT7G3), X = A,C,T; Y = T,G,A, D2-4]. Additionally, the Watson-Crick-pairing of the modified oligomers S2 and S3 was studied. PMID:7567457