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1

ONE-DIMENSIONAL COORDINATION POLYMERS - APPLICATIONS TO MATERIAL SCIENCE  

Microsoft Academic Search

Coordination metal complexes with one-dimensional polymeric structures\\u000a have long been investigated as materials with unusual properties.\\u000a Molecular-based ferromagnets, synthetic metallic conductors, non-linear\\u000a optical materials, and ferroelectrics represent several applications of\\u000a low-dimensional coordination polymers. It is possible to modify the bulk\\u000a magnetic, electrical, and optical properties of such materials by\\u000a tailoring the constituent molecules. This review presents recent\\u000a examples of each

CT CHEN

1993-01-01

2

A coordination polymer consisting of two different one-dimensional copper(II) chains.  

PubMed

The title compound, catena-poly[[[diaqua(methanol-?O)copper(II)]-?-N-(4-methylpyrimidin-2-yl-?N(1))pyrazin-2-amine-?(2)N(1):N(4)] [[aqua(aqua/methanol-?O)(perchlorato-?O)copper(II)]-?-N-(4-methylpyrimidin-2-yl-?N(1))pyrazin-2-amine-?(2)N(1):N(4)] tris(perchlorate) methanol monosolvate 1.419-hydrate], {[Cu(C9H9N5)(CH3OH)(H2O)2][Cu(C9H9N5)(ClO4)(CH3OH)0.581(H2O)1.419](ClO4)3·CH3OH·1.419H2O}n, is a one-dimensional straight-chain polymer of N-(4-methylpyrimidin-2-yl)pyrazin-2-amine (L) with Cu(ClO4)2. The complex consists of two crystallographically independent one-dimensional chains in which the Cu(II) atoms exhibit two different octahedral coordination geometries. The L ligand coordinates to two Cu(II) centres in a tridentate manner, with the pyrazine ring acting as a bridge linking the Cu(II) coordination units and building an infinite one-dimensional chain. Extensive hydrogen bonding among perchlorate anions, water molecules and L ligands results in three-dimensional networks. PMID:24594718

Wu, Yang; Wang, Wen Zhen; Ismayilov, Rayyat Huseyn; Lee, Gene Hsiang; Peng, Shie Ming

2014-03-01

3

Sonochemical synthesis and characterization of new one-dimensional manganese(II) coordination polymer nanostructures.  

PubMed

A new Mn(II) coordination polymer, [Mn (L1)2(NCS)2]n (1) [L1=3,4-bis(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole] was synthesized by the reaction of ligand L1 and mixtures of manganese(II) acetate and potassium thiocyanate using the heat gradient method. Compound 1 has been characterized by IR spectroscopy, elemental analyses and X-ray crystallography. The crystal structure of compound 1 was determined by single-crystal X-ray diffraction and shows a new interesting one-dimensional coordination polymer. Nanostructures of compound 1 have been synthesized by sonochemical method. The products were characterized by X-ray powder diffraction, scanning electron microscopy (SEM), and IR spectroscopy. The thermal stability of nano particles of compound 1 was studied by thermal gravimetric and differential thermal analyses. PMID:25483353

Morsali, Ahmad; Hosseini-Monfared, Hassan; Morsali, Ali; Mayer, Peter

2015-05-01

4

Magnetic study of a one-dimensional Mn(II) coordination polymer dealing with ?-? stacking  

NASA Astrophysics Data System (ADS)

A new one-dimensional chain manganese(II) coordination polymer, {[Mn(?-Dpd)(Q) 2(H 2O) 2]2(ClO 4)} n (Dpd = 2,5-dimethylpyrazine-1,4-dioxide; Q = 8-hydroxylquinoline N-oxide), was synthesized with 2,5-dimethylpyrazine-1,4-dioxide as bridge ligand and 8-hydroxylquinoline N-oxide as terminal ligand, and its crystal structure determined by X-ray crystallography. The structure analysis indicates that there are two pathways for magnetic interactions: one is through bridge ligand 2,5-dimethylpyrazine-1,4-dioxide, and another is by ?-? stacking of adjacent quinoline rings. The theoretical calculations reveal that there exist a anti-ferromagnetic interaction from spin delocalization and a ferromagnetic interaction from spin polarization for 2,5-dimethylpyrazine-1,4-dioxide bridge pathway, but the anti-ferromagnetic interaction is stronger than the ferromagnetic interaction, leading to an anti-ferromagnetic interaction with J = -2.53 cm -1; whereas for the ?-? stacking pathway it resulted in a ferromagnetic interaction with J = 0.013 cm -1. The experimental fitting on the data of the variable temperature magnetic susceptibilities gave the magnetic interaction constant J = 0.07 cm -1, which is similar with the results of the theoretical calculations.

Shi, Jing-Min; Meng, Xian-Zhe; Sun, You-Min; Xu, Hai-Yan; Shi, Wei; Cheng, Peng; Liu, Lian-Dong

2009-01-01

5

One-dimensional imidazole aggregate in aluminium porous coordination polymers with high proton conductivity.  

PubMed

The development of anhydrous proton-conductive materials operating at temperatures above 80 degrees C is a challenge that needs to be met for practical applications. Herein, we propose the new idea of encapsulation of a proton-carrier molecule--imidazole in this work--in aluminium porous coordination polymers for the creation of a hybridized proton conductor under anhydrous conditions. Tuning of the host-guest interaction can generate a good proton-conducting path at temperatures above 100 degrees C. The dynamics of the adsorbed imidazole strongly affect the conductivity determined by (2)H solid-state NMR. Isotope measurements of conductivity using imidazole-d4 showed that the proton-hopping mechanism was dominant for the conducting path. This work suggests that the combination of guest molecules and a variety of microporous frameworks would afford highly mobile proton carriers in solids and gives an idea for designing a new type of proton conductor, particularly for high-temperature and anhydrous conditions. PMID:19734885

Bureekaew, Sareeya; Horike, Satoshi; Higuchi, Masakazu; Mizuno, Motohiro; Kawamura, Takashi; Tanaka, Daisuke; Yanai, Nobuhiro; Kitagawa, Susumu

2009-10-01

6

Syntheses, structures, luminescence, and magnetic properties of one-dimensional lanthanide coordination polymers with a rigid 2,2'-bipyridine-3,3',6,6'-tetracarboxylic acid ligand.  

PubMed

A series of novel one-dimensional (1-D) lanthanide coordination polymers (CPs), with the general formula {[Ln(bptcH)(H(2)O)(2)]·H(2)O}(n) (Ln = Nd(III) (1), Eu(III) (2), Gd(III) (3), Tb(III) (4), Dy(III) (5), Ho(III) (6), or Er(III) (7)) have been synthesized by the solvothermal reactions of the corresponding lanthanide(III) picrates and 2,2'-bipyridine-3,3',6,6'-tetracarboxylic acid (bptcH(4)). These polymers have been structurally characterized by single-crystal X-ray diffraction, IR, PXRD, thermogravimetric (TGA), and elemental analysis. Coordination polymers 1-7 are isostructural; they possess the same 3D supramolecular architectures and crystallize in triclinic space group P1?. The frameworks constructed from dinuclear lanthanide building blocks exhibit one-dimensional double-stranded looplike chain architectures, in which the bptcH(3-) ions adopted hexadentate coordination modes. The Eu(III) (2) and Tb(III) (4) polymers exhibit characteristic photoluminescence in the visible region. The magnetic properties of polymers 2, 3, and 5 have been investigated through the measurement of their magnetic susceptibilities over the temperature range of 1.8-300 K. PMID:22300269

Ji, Baoming; Deng, Dongsheng; He, Xiao; Liu, Bin; Miao, Shaobin; Ma, Ning; Wang, Weizhou; Ji, Liguo; Liu, Peng; Li, Xianfei

2012-02-20

7

A one-dimensional Zn(II) coordination polymer: poly[dichlorido(??-1,4-phenylenediacetato-?²O:O')bis{??-1,3-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene-?²N³:N³'}dizinc(II)].  

PubMed

In the title one-dimensional Zn(II) coordination polymer, [Zn(C10H8O4)(0.5)Cl(C12H12N6)]n, the asymmetric unit consists of a Zn(II) cation, a 1,3-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene ligand and half of a fully deprotonated centrosymmetric 1,4-phenylenediacetic acid ligand. The crystal structure shows a one-dimensional rotaxane-like structure. This coordination polymer is reinforced by C-H···O and C-H···Cl hydrogen bonds and ?-? interactions. PMID:25370101

Xu, Xiao-Juan

2014-11-01

8

A novel one-dimensional manganese(II) coordination polymer containing both dicyanamide and pyrazinamide ligands: Synthesis, spectroscopic investigations, X-ray studies and evaluation of biological activities.  

PubMed

A novel 1D coordination polymer {[Mn(?1,5-dca)2(PZA)2](PZA)2}n, 1, has been synthesized and characterized by single crystal X-ray crystallography. The coordination mode of dicyanamide (dca) and pyrazinamide (PZA) ligands was inferred by IR spectroscopy. The compound 1 was evaluated for in vitro antimycobacterial and antitumor activities. It demonstrated better in vitro activity against Mycobacterium tuberculosis than pyrazinamide and its MIC value was determined. Complex 1 was also screened for its in vitro antitumor activity towards LM3 and LP07 murine cancer cell lines. In addition, the antibacterial activity of complex 1 has been tested against Gram(+) and Gram(-) bacteria and it has shown promising broad range anti-bacterial activity. PMID:25574649

Tabrizi, Leila; Chiniforoshan, Hossein; McArdle, Patrick

2015-03-15

9

Magnetic property and theoretical study on a new one-dimensional coordination polymer [Co(? 1,3-SCN)(?-MPyO)(SCN)(CH 3OH)] n with mixed bridging ligands  

NASA Astrophysics Data System (ADS)

A new one-dimensional coordination polymer [Co(? 1,3-SCN)(?-MPyO)(SCN)(CH 3OH)] n (where MPyO = 4-methylpyridine N-oxide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complexes, there exist two kinds of bridging ligands, namely, ? 1,3-SCN - bridging ligand and ?-MPyO bridging ligand. The two kinds of bridging ligands coordinate to the Co(II) ions with alternating way and which led to the formation of the one-dimensional chain. The density function calculations have been carried out on the complex to analyze the magnetic coupling mechanism. The calculations reveal that magnetic coupling values are J = -20.32 cm -1 from MPyO bridged Co(II) ions and J = -0.87 cm -1 from ? 1,3-SCN - bridged Co(II) ions. The fitting of the susceptibility data (4-300 K) was performed by using one-dimensional Co(II) coupling formula which gave the J = -7.19 cm -1 and J' = -1.28 cm -1.

Shi, Jing-Min; Liu, Zhe; Sun, You-Min; Yi, Long; Liu, Lian-Dong

2006-06-01

10

Polymer Single Crystal Templated by Quasi-One Dimensional Materials  

NASA Astrophysics Data System (ADS)

Quasi-one dimensional materials such as nanotubes and nanofibers can induce polymer crystallization and in many cases, the resultant crystals mimic shish kebabs. This hybrid structure is of great interests from both scientific and technological standpoint. We have explored a few quansi-one dimensional structures such as carbon nanotubes and polymer nanofibers. The growth of the crystals is confined by the quasi-one dimensional nucleating sites provided by the tubes/nanofibers. The crystals formed are sensitive to the surface chemistry and diameter of the materials. Using block copolymers allowed us to achieve templated patterning on these one dimensional structures with controlled spacing and the mechanism was attributed to the crystallization driven block copolymer phase separation. Detailed mechanisms will be discussed.

Li, Bing; Laird, Eric; Chen, Xi; Wang, Wenda; Li, Christopher

2010-03-01

11

Syntheses, structures and magnetic properties of two one-dimensional coordination polymers of cobalt(II) and nickel(II) dicyanamide containing a tridentate N-donor Schiff base  

NASA Astrophysics Data System (ADS)

Two neutral one-dimensional coordination polymers of the type [M(L)(?1,5-dca)(dca)]n [M = Co (1), Ni (2); L = (N,N-diethyl,N'-(pyridin-2-yl)benzylidene)ethane-1,2-diamine; dca = dicyanamide] are isolated through single-pot reactions of a 1:1:2 M ratio of M(OAc)2·4H2O, L and Na(dca) in MeOH solution at room temperature and characterized on the basis of microanalyses, spectroscopic, thermal and other physicochemical results. X-ray structural study reveals that each metal(II) center in both compounds adopts a distorted octahedral geometry with an MN6 chromophore coordinated by three N atoms of the tridentate Schiff base (L) and three nitrile N atoms of one terminal and two single ?1,5 bridged dca units in a meridional alignment; each ?1,5 bridged dca unit connects other neighboring metal centers in a non-ending fashion affording a 1D chain. Variable-temperature magnetic susceptibility measurements of 1 and 2 show weak antiferromagnetic interactions among the metal centers through ?1,5 dca bridges.

Kundu, Subhasish; Roy, Subhasis; Bhar, Kishalay; Ghosh, Rajarshi; Lin, Chia-Her; Ribas, Joan; Ghosh, Barindra Kumar

2013-04-01

12

Luminescent lanthanide coordination polymers  

SciTech Connect

One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate){sub 3}(H{sub 2}O){sub 2} (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a-f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln-(carboxylate){sub 2}-Ln and Ln-(carboxylate){sub 4}-Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate){sub 3}(H{sub 2}O){sub 2} is highly emissive at room temperature with a quantum yield of {approximately}90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P2{sub 1}/c, a = 9.712(2) {angstrom}, b = 19.833(4) {angstrom}, c = 11.616(2) {angstrom}, {beta} = 111.89(3){degree}, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) {angstrom}, b = 11.584(2) {angstrom}, c = 9.839(2) {angstrom}, {beta} = 115.64(3){degree}, Z = 8.

Ma, L.; Evans, O.R.; Foxman, B.M.; Lin, W.

1999-12-13

13

Two helical one-dimensional copper(II) coordination polymers based on N-(2-hydroxylbenzyl)glycine and N-(2-hydroxylbenzyl)- l-alanine: Syntheses, crystal structures and magnetic studies  

Microsoft Academic Search

Two new helical Cu(II) coordination polymers, [Cu(2,2?-bpy)(Hsgly)]Cl·2H2O(H2sgly=N-(2-hydroxylbenzyl)glycine) (1) and [Cu(2,2?-bpy)(Hsala)](NO3)·2H2O(H2sala=N-(2-hydroxylbenzyl)-l-alanine) (2) were synthesized. Single crystal X-ray diffraction analysis indicated that both complexes showed helical chains arrangement of Cu(II) centers bridged by carboxyl groups. The magnetic measurements showed complex 1 exhibited ferromagnetic interaction while there was no interaction between the Cu(II) centers in complex 2.

Zhengliang Lua; Deqing Zhang; Song Gao; Daoben Zhu

2005-01-01

14

Brownian-dynamics computer simulations of a one-dimensional polymer model. I. Simple potentials  

SciTech Connect

Brownian Dynamics computer simulation results are presented on a simple one-dimensional polymer model which contains the essential features of rotational angle flexibility. Comparison is made with analytical treatments of the model.

Cook, R.; Livornese, L.L.

1982-11-01

15

Polymer-loaded propagating modes on a one-dimensional photonic crystal  

SciTech Connect

We numerically and experimentally demonstrate that a polymer film-coated one-dimensional photonic crystal (1DPC) can sustain transverse electric (TE) polarized modes without the limit of guided layer's thickness. Our results indicate that two propagating modes are existing inside the polymer film, the first one is the TE polarized Bloch surface wave, and the second one is the TE polarized guided mode. Here in, the evolution of these two modes with change in the polymer film thickness is presented. Our numerical simulation results are in well-agreement with the experimental data obtained using back focal plane imaging.

Han, Lu; Zhang, Douguo, E-mail: dgzhang@ustc.edu.cn; Chen, Yikai; Wang, Ruxue; Zhu, Liangfu; Wang, Pei; Ming, Hai; Lakowicz, Joseph R., E-mail: jlakowicz@som.umaryland.edu [Department of Optics and Optical Engineering, Institute of Photonics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Badugu, Ramachandram [Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States)

2014-02-10

16

Crystal structure of a one-dimensional helical-type silver(I) coordination polymer: catena-poly[[silver(I)-?-N-(pyridin-4-ylmeth­yl)pyridine-3-amine-?2 N:N?] nitrate dimethyl sulfoxide disolvate  

PubMed Central

The asymmetric unit of the title compound, {[Ag(C11H11N3)]NO3·2(CH3)2SO}n, comprises one AgI atom, one N-(pyridine-4-ylmeth­yl)pyridine-3-amine ligand, one nitrate anion and two dimethyl sulfoxide mol­ecules. The AgI atoms are bridged by two pyridine N atoms from two symmetry-related ligands, forming a helical chain and adopting a slightly distorted linear coordination geometry [N—Ag—N = 175.37?(8)°]. The helical chain, with a pitch length of 16.7871?(8)?Å, propagates along the b-axis direction. In the crystal, symmetry-related right- and left-handed helical chains are alternately arranged via Ag?Ag inter­actions [3.4145?(4)?Å] and ?–? stacking inter­actions [centroid–centroid distance = 3.650?(2)?Å], resulting in the formation of a two-dimensional supra­molecular network extending parallel to (100). Weak Ag?O [2.775?(2), 3.169?(4) and 2.690?(2)?Å] inter­actions, as well as several N—H?O and C—H?O hydrogen-bonding inter­actions, contribute to the stabilization of the crystal structure. Parts of the dimethyl sulfoxide solvent molecule are disordered over two sets of sites in a 0.937?(3):0.063?(3) ratio. PMID:25552978

Moon, Bokhee; Jeon, Youngeun; Moon, Suk-Hee; Park, Ki-Min

2014-01-01

17

Crystal structure of a one-dimensional helical-type silver(I) coordination polymer: catena-poly[[silver(I)-?-N-(pyridin-4-ylmeth-yl)pyridine-3-amine-?(2) N:N'] nitrate dimethyl sulfoxide disolvate].  

PubMed

The asymmetric unit of the title compound, {[Ag(C11H11N3)]NO3·2(CH3)2SO} n , comprises one Ag(I) atom, one N-(pyridine-4-ylmeth-yl)pyridine-3-amine ligand, one nitrate anion and two dimethyl sulfoxide mol-ecules. The Ag(I) atoms are bridged by two pyridine N atoms from two symmetry-related ligands, forming a helical chain and adopting a slightly distorted linear coordination geometry [N-Ag-N = 175.37?(8)°]. The helical chain, with a pitch length of 16.7871?(8)?Å, propagates along the b-axis direction. In the crystal, symmetry-related right- and left-handed helical chains are alternately arranged via Ag?Ag inter-actions [3.4145?(4)?Å] and ?-? stacking inter-actions [centroid-centroid distance = 3.650?(2)?Å], resulting in the formation of a two-dimensional supra-molecular network extending parallel to (100). Weak Ag?O [2.775?(2), 3.169?(4) and 2.690?(2)?Å] inter-actions, as well as several N-H?O and C-H?O hydrogen-bonding inter-actions, contribute to the stabilization of the crystal structure. Parts of the dimethyl sulfoxide solvent molecule are disordered over two sets of sites in a 0.937?(3):0.063?(3) ratio. PMID:25552978

Moon, Bokhee; Jeon, Youngeun; Moon, Suk-Hee; Park, Ki-Min

2014-12-01

18

Infrared phonon anomaly of one-dimensional metallic peanut-shaped C60 polymer  

NASA Astrophysics Data System (ADS)

The infrared (IR) phonon properties of one-dimensional (1D) metallic peanut-shaped C60 polymers, which exhibit an energy gap below 60 K [Y. Toda et al., Appl. Phys. Lett. 92, 094102 (2008)] that is similar to the Peierls transition of quasi-1D metallic materials, have been examined in the temperature range of 30-300 K by high-resolution in-situ IR spectroscopy. We observed an IR phonon anomaly in which two new IR modes appear at 50 K and become increasingly anomalous with decreasing temperature in a similar manner as phase phonons associated with charge density waves in quasi-1D condensates.

Onoe, J.; Takashima, A.; Toda, Y.

2010-12-01

19

Electron-electron interaction effects in quasi-one-dimensional conducting polymers and related systems  

SciTech Connect

We review recent results on the role of electron-electron (e-e) interactions in quasi-one-dimensional conducting polymers and related systems. Within the Peierls-Hubbard model, the effects of both short-range (on-site U and nearest neighbor V/sub 1/) and long-range (V/sub j/, jgreater than or equal to 2) are examined, the former using quantum Monte Carlo and the latter with exact diagonalization of finite size systems and analytic arguments. We also discuss optical absorption properties in the presence of electronic correlation, focusing on the weak and strong coupling limits.

Campbell, D.K.; Baeriswyl, D.; Mazumdar, S.

1986-01-01

20

DOI: 10.1002/chem.200601174 Hydrogencyanamide-Bridged One-Dimensional Polymers Built on  

E-print Network

-bridged chains built on dinuclear [MnIII 2(L)2] units, complexes 3­8, [MnIII 2(L)2(m1,3- NCNH)]ClO4·S (L=salen, 5-Ming Wang, and Song Gao*[a] Introduction The design and synthesis of transition-metal coordination polymers to prepare a number of alkali metal,[2] alkaline-earth metal,[3] and rare-earth metal[4] salts by different

Gao, Song

21

Electro-optic polymer/silicon hybrid slow light modulator based on one-dimensional photonic crystal waveguides  

NASA Astrophysics Data System (ADS)

An electro-optic (EO) modulator composed of EO polymer/silicon hybrid one-dimensional photonic crystal nanobeam waveguides is proposed and experimentally demonstrated. The optical field of the photonic crystal nanobeam is designed to concentrate at the nanoscale low refractive index EO polymer region. We have demonstrated enhanced EO modulation efficiencies as a result of the slower group velocity in the 100-?m-long photonic crystal nanobeam phase-shifters. The results agree well with the behavior predicted from band dispersion characteristics, indicating that EO polymer/silicon hybrid photonic crystal nanobeam waveguides are an effective platform for realizing extremely small and ultrafast EO modulators with low operational power.

Inoue, Shin-ichiro; Otomo, Akira

2013-10-01

22

Anomalous enhancement in the infrared phonon intensity of a one-dimensional uneven peanut-shaped C60 polymer  

NASA Astrophysics Data System (ADS)

A one-dimensional (1D) uneven peanut-shaped C60 polymer formed from electron-beam (EB)-induced polymerization of C60 molecules showed an anomalous increase in two characteristic infrared (IR) peak intensities, which are respectively due to the radial and tangential motion of the 1D polymer, when compared to the IR peaks of pristine C60 films. This anomaly was analyzed on the basis of the vibrational van Hove singularity (VHS), using an extended thin-shell elastic model fully considering the effects of periodic radius modulation inherent to the 1D uneven peanut-shaped C60 polymer. We succeeded in explaining the enhancement in the tangential peak intensity by VHS, whereas the origin to cause that in the radial peak intensity is still unclear.

Onoe, J.; Takashima, A.; Ono, S.; Shima, H.; Nishii, T.

2012-05-01

23

In situ single-crystal to single-crystal (SCSC) transformation of the one-dimensional polymer catena-poly[[diaqua(sulfato)copper(II)]-??-glycine] into the two-dimensional polymer poly[??-glycine-??-sulfato-copper(II)].  

PubMed

The one-dimensional coordination polymer catena-poly[diaqua(sulfato-?O)copper(II)]-?2-glycine-?(2)O:O'], [Cu(SO4)(C2H5NO2)(H2O)2]n, (I), was synthesized by slow evaporation under vacuum of a saturated aqueous equimolar mixture of copper(II) sulfate and glycine. On heating the same blue crystal of this complex to 435?K in an oven, its aspect changed to a very pale blue and crystal structure analysis indicated that it had transformed into the two-dimensional coordination polymer poly[(?2-glycine-?(2)O:O')(?4-sulfato-?(4)O:O':O'':O'')copper(II)], [Cu(SO4)(C2H5NO2)]n, (II). In (I), the Cu(II) cation has a pentacoordinate square-pyramidal coordination environment. It is coordinated by two water molecules and two O atoms of bridging glycine carboxylate groups in the basal plane, and by a sulfate O atom in the apical position. In complex (II), the Cu(II) cation has an octahedral coordination environment. It is coordinated by four sulfate O atoms, one of which bridges two Cu(II) cations, and two O atoms of bridging glycine carboxylate groups. In the crystal structure of (I), the one-dimensional polymers, extending along [001], are linked via N-H···O, O-H···O and bifurcated N-H···O,O hydrogen bonds, forming a three-dimensional framework. In the crystal structure of (II), the two-dimensional networks are linked via bifurcated N-H···O,O hydrogen bonds involving the sulfate O atoms, forming a three-dimensional framework. In the crystal structures of both compounds, there are C-H···O hydrogen bonds present, which reinforce the three-dimensional frameworks. PMID:25370107

Stoeckli-Evans, Helen; Sereda, Olha; Neels, Antonia; Oguey, Sebastien; Ionescu, Catherine; Jacquier, Yvan

2014-11-01

24

Static fluctuations of a thick one-dimensional interface in the 1+1 directed polymer formulation: Numerical study  

NASA Astrophysics Data System (ADS)

We study numerically the geometrical and free-energy fluctuations of a static one-dimensional (1D) interface with a short-range elasticity, submitted to a quenched random-bond Gaussian disorder of finite correlation length ?>0 and at finite temperature T. Using the exact mapping from the static 1D interface to the 1+1 directed polymer (DP) growing in a continuous space, we focus our analysis on the disorder free energy of the DP end point, a quantity which is strictly zero in the absence of disorder and whose sample-to-sample fluctuations at a fixed growing time t inherit the statistical translation invariance of the microscopic disorder explored by the DP. Constructing a new numerical scheme for the integration of the Kardar-Parisi-Zhang evolution equation obeyed by the free energy, we address numerically the time and temperature dependence of the disorder free-energy fluctuations at fixed finite ?. We examine, on one hand, the amplitude D˜t and effective correlation length ?˜t of the free-energy fluctuations and, on the other hand, the imprint of the specific microscopic disorder correlator on the large-time shape of the free-energy two-point correlator. We observe numerically the crossover to a low-temperature regime below a finite characteristic temperature Tc(?), as previously predicted by Gaussian variational method computations and scaling arguments and extensively investigated analytically in [Phys. Rev. E1539-375510.1103/PhysRevE.87.042406 87, 042406 (2013)]. Finally, we address numerically the time and temperature dependence of the roughness B(t), which quantifies the DP end point transverse fluctuations, and we show how the amplitude D˜?(T,?) controls the different regimes experienced by B(t)—in agreement with the analytical predictions of a DP toy model approach.

Agoritsas, Elisabeth; Lecomte, Vivien; Giamarchi, Thierry

2013-06-01

25

Porphyrin coordination polymer nanospheres and nanorods  

DOEpatents

A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.

2012-12-04

26

Static fluctuations of a thick one-dimensional interface in the 1+1 directed polymer formulation  

NASA Astrophysics Data System (ADS)

Experimental realizations of a one-dimensional (1D) interface always exhibit a finite microscopic width ?>0; its influence is erased by thermal fluctuations at sufficiently high temperatures, but turns out to be a crucial ingredient for the description of the interface fluctuations below a characteristic temperature Tc(?). Exploiting the exact mapping between the static 1D interface and a 1+1 directed polymer (DP) growing in a continuous space, we study analytically both the free-energy and geometrical fluctuations of a DP, at finite temperature T, with a short-range elasticity and submitted to a quenched random-bond Gaussian disorder of finite correlation length ?. We derive the exact time-evolution equations of the disorder free energy F¯(t,y), which encodes the microscopic disorder integrated by the DP up to a growing time t and an endpoint position y, its derivative ?(t,y), and their respective two-point correlators C¯(t,y) and R¯(t,y). We compute the exact solution of its linearized evolution R¯lin(t,y) and we combine its qualitative behavior and the asymptotic properties known for an uncorrelated disorder (?=0) to justify the construction of a “toy model” leading to a simple description of the DP properties. This model is characterized by Gaussian Brownian-type free-energy fluctuations, correlated at small |y|??, and of amplitude D˜?(T,?). We present an extended scaling analysis of the roughness, supported by saddle-point arguments on its path-integral representation, which predicts D˜?˜1/T at high temperatures and D˜?˜1/Tc(?) at low temperatures. We identify the connection between the temperature-induced crossover of D˜?(T,?) and the full replica symmetry breaking in previous Gaussian variational method (GVM) computations. In order to refine our toy model with respect to finite-time geometrical fluctuations, we propose an effective time-dependent amplitude D˜t. Finally, we discuss the consequences of the low-temperature regime for two experimental realizations of Kardar-Parisi-Zhang interfaces, namely, the static and quasistatic behavior of magnetic domain walls and the high-velocity steady-state dynamics of interfaces in liquid crystals.

Agoritsas, Elisabeth; Lecomte, Vivien; Giamarchi, Thierry

2013-04-01

27

Anomaly in the electric resistivity of one-dimensional uneven peanut-shaped C60 polymer film at a low temperature  

NASA Astrophysics Data System (ADS)

We performed in situ four-probe measurements of the current-voltage characteristics of one-dimensional (1D) uneven peanut-shaped C60 polymer films in the temperature range 30-350 K under ultrahigh vacuum conditions (2 × 10-7 Pa). Arrhenius plots of the film resistance with respect to temperature showed two different electron-conduction mechanisms. While electrons are conducted via a thermal excitation hopping at temperatures above 160 K, the resistivity of the 1D polymer film exhibits an anomalous behavior that becomes fluctuated at a given value in the temperature range 40-90 K and decreases at temperatures below 40 K.

Ryuzaki, Soh; Onoe, Jun

2014-03-01

28

Anomaly in the electric resistivity of one-dimensional uneven peanut-shaped C{sub 60} polymer film at a low temperature  

SciTech Connect

We performed in situ four-probe measurements of the current-voltage characteristics of one-dimensional (1D) uneven peanut-shaped C{sub 60} polymer films in the temperature range 30–350?K under ultrahigh vacuum conditions (2?×?10{sup ?7}?Pa). Arrhenius plots of the film resistance with respect to temperature showed two different electron-conduction mechanisms. While electrons are conducted via a thermal excitation hopping at temperatures above 160?K, the resistivity of the 1D polymer film exhibits an anomalous behavior that becomes fluctuated at a given value in the temperature range 40–90?K and decreases at temperatures below 40?K.

Ryuzaki, Soh; Onoe, Jun, E-mail: jonoe@nr.titech.ac.jp [Research Laboratory for Nuclear Reactors and Department of Nuclear Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8550 (Japan)

2014-03-17

29

An innovative method for coordinate measuring machine one-dimensional self-calibration with simplified experimental process  

NASA Astrophysics Data System (ADS)

In this paper, an innovative method for CMM (Coordinate Measuring Machine) self-calibration is proposed. In contrast to conventional CMM calibration that relies heavily on a high precision reference standard such as a laser interferometer, the proposed calibration method is based on a low-cost artefact which is fabricated with commercially available precision ball bearings. By optimizing the mathematical model and rearranging the data sampling positions, the experimental process and data analysis can be simplified. In mathematical expression, the samples can be minimized by eliminating the redundant equations among those configured by the experimental data array. The section lengths of the artefact are measured at arranged positions, with which an equation set can be configured to determine the measurement errors at the corresponding positions. With the proposed method, the equation set is short of one equation, which can be supplemented by either measuring the total length of the artefact with a higher-precision CMM or calibrating the single point error at the extreme position with a laser interferometer. In this paper, the latter is selected. With spline interpolation, the error compensation curve can be determined. To verify the proposed method, a simple calibration system was set up on a commercial CMM. Experimental results showed that with the error compensation curve uncertainty of the measurement can be reduced to 50%.

Fang, Cheng; Butler, David Lee

2013-05-01

30

Photophysics of excitons in quasi-one-dimensional organic semiconductors: Single-walled carbon nanotubes and pi -conjugated polymers  

Microsoft Academic Search

The nature of the primary photoexcitations in semiconducting single-walled carbon nanotubes (S-SWCNTs) is of strong current interest. We have studied the emission spectra of S-SWCNTs and two different pi -conjugated polymers in solutions and films, and have also performed ultrafast pump-probe spectroscopy on these systems with unprecedented spectral range from 0.1to2.6eV . The emission spectra relative to the absorption bands

H. Zhao; S. Mazumdar; C.-X. Sheng; M. Tong; Z. V. Vardeny

2006-01-01

31

In situ infrared spectroscopic and density-functional studies of the cross-linked structure of one-dimensional C{sub 60} polymer  

SciTech Connect

We have examined the infrared (IR) spectra of electron-beam (EB) irradiated C{sub 60} films, using in situ IR spectroscopy in the temperature range of 60-300 K. The irradiation-time evolution of the IR spectra shows that two highly intense new peaks finally appear around 565 and 1340 cm{sup -1} when the EB-induced C{sub 60} polymerization was saturated. To determine the cross-linked structure of the polymer explicitly, we have compared the IR spectra with theoretical spectra obtained from the cross-linked structure of all C{sub 120} stable isomers derived from the general Stone-Wales (GSW) rearrangement, using first-principles density-functional calculations. Since each C{sub 120} isomer has the same cross-linked structure as that of its corresponding one-dimensional (1D) C{sub 60} polymer, the IR modes obtained from the cross-linked structure of C{sub 120} are close to those obtained from the corresponding 1D polymer. Comparison between the experimental and theoretical IR spectra suggests that the 1D peanut-shaped C{sub 60} polymer has a cross-linked structure roughly similar to that of the P08 peanut-shaped C{sub 120} isomer.

Takashima, A.; Onoe, J. [Department of Nuclear Engineering and Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama, Meguro, Tokyo 152-8550 (Japan); Nishii, T. [Technology Development Center, Electric Power Development Co., Ltd. (J-Power), Chigasaki, Kanagawa 253-0041 (Japan)

2010-08-15

32

Structure and electronic properties of the nanopeapods-One dimensional C{sub 60}O polymer encapsulated in single-walled carbon nanotubes  

SciTech Connect

The structure-property relationship of the nanopeapods-one dimensional (1D) C{sub 60}O polymer encapsulated in single-walled carbon nanotubes (SWCNTs)-is studied by means of the self-consistent field crystal orbital method. The calculations show that the nearest distance between the two constituents is within Van der Waals interaction scope in the most stable two peapods. The SWCNT sizes affect not only the stability but also the electronic structures of the peapods. The peapods with larger tube diameters keep the semiconductive and metallic properties of the corresponding pristine SWCNTs. These combination systems are stiffer than the corresponding SWCNTs due to larger Young's moduli. The magnitude order of the calculated mobility of charge carriers is in the range of 10{sup 2}-10{sup 5} cm{sup 2} V{sup -1} s{sup -1} for the peapods, indicating that the combined systems may be good high-mobility electronic materials. - Graphical abstract: Formation of the novel peapod-1D C{sub 60}O polymer encapsulated inside single-walled carbon nanotube. Highlights: Black-Right-Pointing-Pointer Several novel peapods encapsulating one dimensional C{sub 60}O polymers are constructed. Black-Right-Pointing-Pointer Interwall distance of the two most stable peapods is in the Van der Waals scope. Black-Right-Pointing-Pointer All peapods studied are stiffer than the corresponding SWCNTs. Black-Right-Pointing-Pointer These peapods have high mobilies-in the order of 10{sup 2}-10{sup 5} cm{sup 2} V{sup -1} s{sup -1}.

Qiao Weiye [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Li Xinqian [Institute for Materials Chemistry and Engineering and International Research Center for Molecular Systems, Kyushu University, Fukuoka 819-0395 (Japan); Bai Hongcun; Zhu Ying [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Huang Yuanhe, E-mail: yuanhe@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

2012-02-15

33

Synthesis, crystal structure and magnetic properties of a one-dimensional copper(II) polymer bridged by different double end-on azide bridges  

NASA Astrophysics Data System (ADS)

A one-dimensional (1D) copper(II) complex [Cu 3(? 1,1-N 3) 6(dmp) 2] n ( 1) has been synthesized and structurally characterized. The molecular structure of 1 is constructed by trimeric [Cu 3(? 1,1-N 3) 6(dmp) 2] units formed through two double symmetric (basal-to-basal) end-on (EO) azide bridges and the trimeric units are connected further by double asymmetric (basal-to-apical) EO azide bridges, giving 1D chain-like structure. The chains of 1 are linked together by N-H⋯N azide hydrogen bonds and very weak Cu⋯N azide coordination interactions from ?-1,1,3,3-N 3 fashion to form two-dimensional (2D) supramolecular architecture. The magnetic structure can be considered as uniform 1D chain formed by linear trimeric Cu II-Cu II-Cu II units and the dominating magnetic coupling occurs within the trimeric Cu3II unit. The magnetic study shows that the compound exhibits ferromagnetic interactions with Jt = + 8.36(2) cm -1 and Jc = + 0.35(4) cm -1 for intratrimeric and intertrimeric Cu3II unit based on 1D magnetic model, respectively.

Zhang, Li-Fang; Yu, Ming-Ming; Ni, Zhong-Hai; Cui, Ai-Li; Kou, Hui-Zhong

2011-12-01

34

One Dimensional Collision Model  

NSDL National Science Digital Library

The One Dimensional Collision model allows the user to collide two objects and investigate whether momentum and/or kinetic energy are conserved in the collision process. To keep things simple, we'll confine ourselves to collisions along a single line. Special cases include the completely inelastic case, in which the objects stick together after the collision, as well as the completely elastic case, in which kinetic energy is conserved. The One Dimensional Collision was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_Collisions1D.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-28

35

Slow Chemical Exchange in an Eight-Coordinated Bicentered Ruthenium Complex Studied by One-Dimensional Methods. Data Fitting and Error Analysis  

NASA Astrophysics Data System (ADS)

Threefold carbonyl rotation in Ru 2(CO) 6(? 2- PPh 2)(? 2- ? 1:? 2- C?C - i- Pr) provides an excellent system for studying slow chemical exchange. One-dimensional relaxation-type experiments, in which spin-lattice relaxation and exchange compete, are performed to see if the threefold rotation is concerted, or a series of pairwise exchanges. Crucial to this study are the error estimates of the parameters; thus, methods for data fitting and error analysis are presented. The conclusions are that the process is concerted, and the barrier is approximately 46 kJ/mol. As an appendix, a discussion of the principle of detailed balance in complex systems, such as the present, is given. This solves the standard kinetic problem of what is the equilibrium state which results from a general kinetic scheme.

Bain, Alex D.; Cramer, J. A.

36

Tuning the magneto-structural properties of non-porous coordination polymers by HCl chemisorption.  

PubMed

Responsive materials for which physical or chemical properties can be tuned by applying an external stimulus are attracting considerable interest in view of their potential applications as chemical switches or molecular sensors. A potential source of such materials is metal-organic frameworks. These porous coordination polymers permit the physisorption of guest molecules that can provoke subtle changes in their porous structure, thus affecting their physical properties. Here we show that the chemisorption of gaseous HCl molecules by a non-porous one-dimensional coordination polymer instigates drastic modifications in the magnetic properties of the material. These changes result from profound structural changes, involving cleavage and formation of covalent bonds, but with no disruption of crystallinity. PMID:22569372

Coronado, Eugenio; Giménez-Marqués, Mónica; Espallargas, Guillermo Mínguez; Brammer, Lee

2012-01-01

37

Syntheses and structural studies of coordination polymers with microporous frameworks  

NASA Astrophysics Data System (ADS)

The purpose of this work is to synthesize microporous solids using coordination chemistry. The syntheses were carried by diffusion method. Starting reagents, solvent, concentration, reaction speed and time, and temperature were the variables used to optimize the syntheses. The resulting products were characterized by single crystal X-ray diffraction to determine their structures. X-ray powder diffraction, TGA, IR, elemental analysis, and electron microprobe were used to provide complementary or supporting information. Exploratory studies were carried out mainly on organotin-cyanometalate compounds [(RmSnIV)x{M(CN)n} y]. The compounds are made up of SnRm cations and M(CN) n anions. The structures adopted are determined by the number and size of the organic ligands attached to the Sn atoms and by the cyanometalate M(CN) n moiety. Several new compounds in this class were synthesized and structurally characterized. They are [(Bu3Sn)3M(CN)6] (M = Fe, Co), [(R2Sn)3{CO(CN)6}2·X] (R = vinyl, butyl, and propyl), and [(Ph3Sn)2Ni(CN) 4 Ph3SnOH·˜0.8CH3CN·˜0.2H 2O]. The compound [(Ph3Sn)2Ni(CN)4·Ph 3SnOH·˜0.8CH3CN·˜0.2H2O] is to our knowledge, the first three dimensional cyanometalate coordination polymer with expanded inorganic NbO structure. The framework is not interpenetrated and the large central cavity in the structure is filled by inclusion of Ph 3SnOH and other solvent molecules during synthesis. In addition to the investigation of organotin-cyanometalate compounds, other approaches to microporous solids were also studied. A new compound [Co(H 2O)2Ni(CN)4·4H2O] in the Hofmann's clathrate family was obtained. Five one dimensional polymers synthesized by the reaction of dirhodium(II) tetraacetate with 1,4-dicyanobenzene in different solvent systems were also synthesized, and the effect of solvent on the resulting structures was investigated.

Niu, Tianyan

38

Coordination polymers of uranium(iv) terephthalates.  

PubMed

A series of tetravalent uranium terephthalates has been solvothermally synthesized in the solvent N,N-dimethylformamide (DMF) at temperature 100-150 °C with different water amounts. Composition diagrams have been determined for the U(4+) metallic cation in the presence of terephthalic acid, and their crystal structures revealed the occurrence of two- or three-dimensional coordination polymers. In the absence of water, a mixture of two polytypes T-U2Cl2(bdc)3(DMF)4 () and M-U2Cl2(bdc)3(DMF)4 () has been identified at low temperature (100-110 °C) for bdc/U = 1-4 (bdc = terephthalate linker). Their structures are built up from isolated uranium centers in nine-fold coordination, surrounded by 6 carboxyl oxygen atoms, 2 oxygen atoms coming from DMF molecules and one chlorine atom. The uranium cations are linked to each other through the bdc ligand in order to generate a 3D framework. By increasing the temperature (130-150 °C), a layered like compound has been isolated, U2(bdc)4(DMF)4 (). It is composed of discrete actinide centers in ten-fold coordination, with 8 carboxyl oxygen atoms and 2 oxygen atoms from DMF molecules. The connection of the UO10 units with the bdc linkers generates 2D sheets. When a controlled amount of water is added to the reaction medium, the crystallization of the UiO-66-like U6O4(OH)4(H2O)6(bdc)6·10DMF solid (containing a hexanuclear sub-unit) is observed for temperature 110-120 °C and the H2O/U molar ratio in the range of 2-10. At higher temperature (140-150 °C), a distinct phase appeared, U2O2(bdc)2(DMF) (), which consists of infinite chains of uranium centers, linked to each other via the bdc ligands. Higher water contents led to the formation of urania UO2. PMID:25428593

Falaise, Clément; Assen, Ayalew; Mihalcea, Ionut; Volkringer, Christophe; Mesbah, Adel; Dacheux, Nicolas; Loiseau, Thierry

2015-01-28

39

Formation process and electron-beam incident energy dependence of one-dimensional uneven peanut-shaped C60 polymer studied using in situ high-resolution infrared spectroscopy and density-functional calculations  

NASA Astrophysics Data System (ADS)

A 3 kV electron-beam irradiation of a C60 film gives rise to formation of one-dimensional (1D) uneven peanut-shaped C60 polymer with a cross-linked structure close to that of the P08 C120 stable isomer obtained from the general Stone-Wales rearrangement. In this study, we examined the evolution of infrared (IR) spectra of C60 films with respect to electron beam (EB) irradiation time, using in situ high-resolution IR spectroscopy and first-principles density-functional calculations, and found semi-quantitatively that the 1D uneven peanut-shaped C60 polymer is formed via intermediate polymers with a cross-linkage close to that of P04 and P06 C120 isomers obtained from GWS rearrangement. In addition, we examined the dependence of EB-induced C60 polymerization on an incident energy of EB in the range 3-7 kV. IR spectra obtained for 5 and 7 kV EB irradiation of C60films showed the same product as for 3 kV EB irradiation. However, when 5 and 7 kV EBs continued to irradiate C60 films for a long time after the polymer formation, the 1D peanut-shaped polymer did not proceed to become 1D polymers with a more coalesced linkage than that of the P08 one but was destroyed to become amorphous carbons.

Takashima, Akito; Nishii, Toshiaki; Onoe, Jun

2012-12-01

40

Nanoscale coordination polymers for anticancer drug delivery  

NASA Astrophysics Data System (ADS)

This dissertation reports the synthesis and characterization of nanoscale coordination polymers (NCPs) for anticancer drug delivery. Nanoparticles have been explored in order to address the limitations of small molecule chemotherapeutics. NCPs have been investigated as drug delivery vehicles as they can exhibit the same beneficial properties as the bulk metal-organic frameworks as well as interesting characteristics that are unique to nanomaterials. Gd-MTX (MTX = methotrexate) NCPs with a MTX loading of 71.6 wt% were synthesized and stabilized by encapsulation within a lipid bilayer containing anisamide (AA), a small molecule that targets sigma receptors which are overexpressed in many cancer tissues. Functionalization with AA allows for targeted delivery and controlled release to cancer cells, as shown by enhanced efficacy against leukemia cells. The NCPs were doped with Ru(bpy)32+ (bpy = 2,2'-bipyridine), and this formulation was utilized as an optical imaging agent by confocal microscopy. NCPs containing the chemotherapeutic pemetrexed (PMX) were synthesized using different binding metals. Zr-based materials could not be stabilized by encapsulation with a lipid bilayer, and Gd-based materials showed that PMX had degraded during synthesis. However, Hf-based NCPs containing 19.7 wt% PMX were stabilized by a lipid coating and showed in vitro efficacy against non-small cell lung cancer (NSCLC) cell lines. Enhanced efficacy was observed for formulations containing AA. Additionally, NCP formulations containing the cisplatin prodrug disuccinatocisplatin were prepared; one of these formulations could be stabilized by encapsulation within a lipid layer. Coating with a lipid layer doped with AA rendered this formulation an active targeting agent. The resulting formulation proved more potent than free cisplatin in NSCLC cell lines. Improved NCP uptake was demonstrated by confocal microscopy and competitive binding assays. Finally, a Pt(IV) oxaliplatin prodrug was synthesized and incorporated in different NCPs using various binding metals. A moderate drug loading of 44.9 wt% was determined for Zr-based NCPs. This drug loading, along with a diameter less than 200 nm, make these particles promising candidates for further stabilization via lipid encapsulation.

Phillips, Rachel Huxford

41

Crystal structures and luminescent properties of lanthanide nitrate coordination polymers with structurally related amide type bridging podands  

SciTech Connect

A one-dimensional linear chain coordination polymer [ErL{sup I}(NO{sub 3}){sub 3}(CH{sub 3}CO{sub 2}Et)]{sub n} (L{sup I}=1,2-bis{l_brace}[(2'-furfurylaminoformyl)phenoxyl]methyl{r_brace}benzene) and a one-dimensional zig-zag coordination polymer {l_brace}[TbL{sup II}(NO{sub 3}){sub 3}(H{sub 2}O)].(H{sub 2}O){r_brace}{sub n} (L{sup II}=1,2-bis{l_brace}[2'-(2-pyridylmethylaminoformyl)phenoxyl]methyl{r_brace}benzene) were assembled by two structurally related bridging podands L{sup I} and L{sup II} which have uniform skeleton and different terminal groups. In {l_brace}[TbL{sup II}(NO{sub 3}){sub 3}(H{sub 2}O)].(H{sub 2}O){r_brace}{sub n}, the neutral chains were linked by the hydrogen bonding interactions between the free and coordinated water molecules from two different directions to interpenetrate into a 3D supramolecular structure. At the same time, the luminescent properties of the solid Tb(III) nitrate complexes of these podands were investigated at room temperature. The lowest triplet state energy levels T{sub 1} of the podands L{sup I} and L{sup II} indicate that the triplet state energy levels of the antennae are both above the lowest excited resonance level of {sup 5}D{sub 4} of Tb{sup 3+} ion. Thus the absorbed energy could be transferred from ligands to the central Tb{sup 3+} ions. And the influence of the hydrogen bonding on the luminescence efficiencies of the coordination polymers was also discussed. -- Graphical Abstract: Two one-dimensional lanthanide coordination polymers were assembled by two structurally related bridging podands, and the effects of the structures on luminescent properties of the solid Tb(III) nitrate complexes were investigated. Display Omitted Research highlights: > Two structurally related amide type bridging ligands were designed and synthesized. > Two one dimensional lanthanide nitrate coordination polymers were obtained. > The structure effects on luminescent properties of the terbium complexes were discussed.

Wang, Qing; Yan, Xuhuan; Zhang, Hongrui; Liu, Weisheng [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Tang, Yu, E-mail: tangyu@lzu.edu.c [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Tan, Minyu [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

2011-01-15

42

Homochiral coordination polymers constructed from aminocarboxylate derivates: Effect of bipyridine on the amidation reaction  

NASA Astrophysics Data System (ADS)

Using aminocarboxylate derivates (S)-N-(4-cyanobenzoic)-glutamic acid (denoted as cbg, 1a) and (S)-N-(4-nitrobenzoic)-glutamic acid (denoted as nbg, 1b) as chiral ligands, five new homochiral coordination polymers formulated as [Cu(cbg)(H2O)2]n (3), [Cu(cbop)2(4,4'-bipy)(H2O)]n (4) (cbop=(S)-N-(4-cyanobenzoic)-5-oxoproline, 4,4'-bipy=4,4'-bipyridine), {[Cu(nbop)2(4,4'-bipy)]·4H2O}n (5) (nbop=(S)-N-(4-nitrobenzoic)-5-oxoproline), {[Cd(nbop)2(4,4'-bipy)]·2H2O}n (6), and [Ni(nbop)2(4,4'-bipy)(H2O)2]n (7) have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction study reveals that the original chirality of aminocarboxylate derivates is maintained in all these complexes. Complexes 3, 4, and 7 are one-dimensional infinite chain coordination polymers, while complexes 5 and 6 possess two-dimensional network structures. In situ cyclization of 1a and 1b was taken place in the formation of complexes 4-7, which may be due to the competition of 4,4'-bipyridine with chiral ligands during the coordination process. Preliminary optical behavior investigation indicates that ligands 1a, 1b, and complexes 6, 7 are nonlinear optical active.

Chen, Jianshan; Sheng, Tianlu; Hu, Shengmin; Xiang, Shengchang; Fu, Ruibiao; Zhu, Qilong; Wu, Xintao

2012-08-01

43

One-Dimensional Heat Equation  

NSDL National Science Digital Library

Using Maple or Mathmatica, the learner will study the symbolic form and graphical representation of the approximate solutions of the one-dimensional heat equation with various boundary and initial conditions.

Smith, David

2002-01-12

44

Assembly of three coordination polymers based on a sulfonic-carboxylic ligand showing high proton conductivity.  

PubMed

Three new coordination polymers (CPs)/metal-organic frameworks (MOFs) with different structures have been synthesized using 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid (H4L) and metal ions, Cu(2+), Ca(2+) and Cd(2+). The Cu compound features a one-dimensional chain structure, further extending into a 2D layer network through H-bond interactions. Both the Ca and Cd compounds show 3D frameworks with (4,4)-connected PtS-type topology and (3,6)-connected bct-type topology, respectively. These CPs/MOFs all exhibit proton conduction behavior, especially for the Cu compound with a proton conductivity of 3.46 × 10(-3) S cm(-1) at 368 K and 95% relative humidity (RH). Additionally, the activation energy (Ea) has also been investigated to deeply understand the proton-conduction mechanism. PMID:25406590

Zhao, Shu-Na; Song, Xue-Zhi; Zhu, Min; Meng, Xing; Wu, Lan-Lan; Song, Shu-Yan; Wang, Cheng; Zhang, Hong-Jie

2015-01-21

45

EXAFS study of some coordination polymers of copper  

NASA Astrophysics Data System (ADS)

The EXAFS spectra for (1) azelaic acid bis phenyl hydrazide, (2) azelaic acid bis 2,4 dinitro phenyl hydrazide and (3) sebacic acid bis phenyl hydrazide coordination polymers of copper were obtained using the EXAFS facility of the Daresbury Laboratory. The EXAFS analysis revealed that copper is surrounded by four nitrogen and two oxygen atoms in the first coordination shell, while the second coordination shell consists of two carbon atoms. This information suggests the octahedral geometry for the repeating units of polymeric complexes, in contrast to the square planar geometry previously proposed.

Deshpande, A. P.

1995-02-01

46

A new redox-active coordination polymer with cobalticinium dicarboxylate.  

PubMed

A new two-dimensional coordination polymer with cobalticinium 1,1'-dicarboxylate (ccdc) incorporated in the framework has been prepared, the ccdc functioning as unique monoanionic dicarboxylate ligands. The compound shows a high redox activity based on the ccdc units. PMID:15360228

Kondo, Mitsuru; Hayakawa, Yuri; Miyazawa, Makoto; Oyama, Aiko; Unoura, Kei; Kawaguchi, Hiroyuki; Naito, Tetsuyoshi; Maeda, Kenji; Uchida, Fumio

2004-09-20

47

Zipped-up chain-type coordination polymers: unsymmetrical amide-containing ligands inducing beta-sheet or helical structures. kazu-u@yamaguchi-u.ac.jp.  

PubMed

The crystal structures of thirteen AgI coordination polymers involving py-CONH-(CH2)n-py (py=pyridine; n=0, 1) derivatives were determined by means of single-crystal X-ray analyses. All of the compounds form one-dimensional chains composed of AgI atoms and bridging ligands with formulas [[Ag(py-CONH-(CH2)n-py)][X

Uemura, Kazuhiro; Kumamoto, Yuki; Kitagawa, Susumu

2008-01-01

48

Lanthanide-polyphosphonate coordination polymers combining catalytic and photoluminescence properties.  

PubMed

A rapid, mild and high-yield microwave synthesis of 1D isotypical [Ln(H4bmt)(H5bmt)(H2O)2]·3H2O coordination polymers is presented. The La(3+)-based material is highly active as a heterogeneous catalyst in the methanolysis of styrene oxide at nearly room temperature. Eu(3+)- and Tb(3+)-doped materials are very effective UV-to-visible light converters. PMID:23752868

Vilela, Sérgio M F; Firmino, Ana D G; Mendes, Ricardo F; Fernandes, José A; Ananias, Duarte; Valente, Anabela A; Ott, Holger; Carlos, Luís D; Rocha, João; Tomé, João P C; Paz, Filipe A Almeida

2013-07-21

49

Coordination polymer gels with important environmental and biological applications.  

PubMed

Coordination Polymer Gels (CPGs) constitute a subset of solid-like metal ion and bridging organic ligand structures (similar to metal-organic frameworks) that form multi-dimensional networks through a trapped solvent as a result of non-covalent interactions. While physical properties of these gels are similar to conventional high molecular weight organic polymer gels, coordination polymer gel systems are often fully reversible and can be assembled and disassembled in the presence of additional energy (heat, sonication, shaking) to give a solution of solvated gelators. Compared to gels resulting from purely organic self-assembled low molecular weight gelators, metal ions incorporated into the fibrilar networks spanning the bulk solvent can impart CPGs with added functionalities. The solid/liquid nature of the gels allows for species to migrate through the gel system and interact with metals, ligands, and the solvent. Chemosensing, catalysis, fluorescence, and drug-delivery applications are some of the many potential uses for these dynamic systems, taking advantage of the metal ion's coordination, the organic polydentate ligand's orientation and functionality, or a combination of these properties. By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged. PMID:23192282

Jung, Jong Hwa; Lee, Ji Ha; Silverman, Julian R; John, George

2013-02-01

50

A novel cobalt (I) coordination polymer with mixed thiocyanate and quinoline ligands: crystal structure, magnetism and luminescent properties.  

PubMed

A new Co(I) one-dimensional coordination polymer [Co(SCN)(ql)]n (ql=quinoline) (1) has been synthesized and characterized by IR, elemental analysis, TG technique and X-ray crystallography. Co(I) atom has a distorted trigonal pyramidal N2S2 (1) environment with two S atoms and one N atom from three ?-1,1,3-thiocyanate bridge ligands and one N atom from ql ligand. Two S atoms from two ?-1,1,3-SCN- bridging ligands bridge two centers to obtain bimetallic 4-membered ring. Adjacent 4-membered rings are linked by a pair of ?-1,1,3-SCN- bridging ligands to form a 1D stair-case like chain. The luminescent properties and magnetic properties of the polymer 1 were investigated in the solid state. PMID:24211622

Li, Lei; Chen, Shuai; Zhou, Rui-Min; Bai, Yan; Dang, Dong-Bin

2014-01-01

51

Pore design of two-dimensional coordination polymers toward selective adsorption.  

PubMed

We have synthesized four porous coordination polymers (PCPs) using Zn(2+), 4,4'-sulfonyldibenzoate (sdb), and four types of dinitrogen linker ligands, 1,4-diazabicyclo[2,2,2]octane (dabco), 1,4-bis(4-pyridyl)benzene (bpb), 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine (bpt), and 4,4'-bipyridyl (bpy). The bent sdb ligands form a rhombic space connected by zinc paddle-wheel units to form a one-dimensional double chain, and each dinitrogen ligand linked the one-dimensional double chains. There are different assembled structures of two-dimensional sheets with the same connectivities between Zn(2+) and the organic ligands. [Zn2(sdb)2(dabco)]n (1) has a noninterpenetrated and noninterdigitated structure, [Zn2(sdb)2(bpb)]n (2) and [Zn2(sdb)2(bpt)]n (3) have interdigitated structures, and [Zn2(sdb)2(bpy)]n (4) has an interpenetrated structure. The length of the dinitrogen ligands dominated their assembled structures and flexibility, which influence the adsorption properties. The flexible frameworks of 2 and 3 provide different stepwise adsorption behaviors for CO2, CH4, C2H6, and C2H4 affected by their pore diameters and the properties of the gases. Their different adsorption properties were revealed by IR spectroscopy and X-ray analysis under a gas atmosphere. The framework of 4 possesses less flexibility and a smaller void space than the others and a negligible amount of CH4 was adsorbed; however, 4 can adsorb either C2H6 or C2H4 through the gate-opening phenomenon. Measurement of the solid-state (2)H NMR was also carried out to investigate the relationship between the framework structure and the dynamics of bpy with regard to the lower flexibility of 4. We have demonstrated a strategy to control the pore size and assembled structures toward selective adsorption properties of PCPs. PMID:23496290

Hijikata, Yuh; Horike, Satoshi; Sugimoto, Masayuki; Inukai, Munehiro; Fukushima, Tomohiro; Kitagawa, Susumu

2013-04-01

52

One dimensional metal string complexes  

NASA Astrophysics Data System (ADS)

The metal string complexes with different metal ions and various lengths have been successfully synthesized and structurally characterized. The crystal and molecular structure of nonanickel complex [Ni 9(? 9-(peptea) 4Cl 2] which is the longest metal string at this moment will be reported. Crystal data for [Ni 9(? 9-(peptea) 4Cl 2](C 2H 4Cl 2) 10: Space group, monoclinic C 2/c, a=27.0453(6), b=42.6678(5), c=37.4268(6) Å, ?=109.539(1)°, V=40702(1) Å 3, Z=12, R F=12% for the observed reflections ( I>2 ?( I)). The band structure calculation of infinite one-dimensional metal chains of Ni II and Cr II based on the structure of nonanickel complex will be presented. Finally, the metal string complexes [M IInL 4X 2] will be chemisorbed on the Ag or Au surface and the potential application of these complexes as a molecular metal wire will be demonstrated.

Peng, Shie-Ming; Wang, Chih-Chieh; Jang, Yih-Lih; Chen, Yu-Hua; Li, Feng-Yin; Mou, Chung-Yuan; Leung, Man-Kit

2000-01-01

53

Two-Dimensional Coordination Polymers with One-Dimensional Magnetic Chains: Hydrothermal Synthesis, Crystal Structure, and Magnetic and Thermal Properties of  

E-print Network

, Crystal Structure, and Magnetic and Thermal Properties of 2 [MCl2(4,4-bipyridine)] (M ) Fe, Co, Ni, Co to orthorhombic crystal system, space group Cmmm (No. 65). Crystal data for I: a ) 11.929(2) Ã?, b ) 11.447(2) Ã?, c ) 3.638(1) Ã?, V ) 496.77(18) Ã?3, Z ) 2. Crystal data for II: a ) 11.993(2) Ã?, b ) 11.374(2) Ã?, c ) 3

Li, Jing

54

One- and two-dimensional Cd(II) coordination polymers incorporating organophosphinate ligands.  

PubMed

Reaction of cadmium nitrate with diphenylphosphinic acid in dimethylformamide solvent yielded the one-dimensional coordination polymer catena-poly[[bis(dimethylformamide-?O)cadmium(II)]-bis(?-diphenylphosphinato-?(2)O:O')], [Cd(C12H10O2P)2(C3H7NO)2]n, (I). Addition of 4,4'-bipyridine to the synthesis afforded a two-dimensional extended structure, poly[[(?-4,4'-bipyridine-?(2)N:N')bis(?-diphenylphosphinato-?(2)O:O')cadmium(II)] dimethylformamide monosolvate], {[Cd(C12H10O2P)2(C10H8N2)]·C3H7NO}n, (II). In (II), the 4,4'-bipyridine molecules link the Cd(II) centers in the crystallographic a direction, while the phosphinate ligands link the Cd(II) centers in the crystallographic b direction to complete a two-dimensional sheet structure. Consideration of additional ?-? interactions of the phenyl rings in (II) produces a three-dimensional structure with channels that encapsulate dimethylformamide molecules as solvent of crystallization. Both compounds were characterized by single-crystal X-ray diffraction and FT-IR analysis. PMID:25370109

Rood, Jeffrey A; Boyer, Steven; Oliver, Allen G

2014-11-01

55

CO(2) selective 1D double chain dipyridyl-porphyrin based porous coordination polymers.  

PubMed

Thermal reactions of MnCl(DPyP) (DPyP = 5,15-di(4-pyridyl)-10,20-diphenylporphyrin) as a metalloligand with Co(II) and Zn(II) ions in dimethylformamide led to neutral one-dimensional (1D) double chain dipyridyl-porphyrin-based porous coordination polymers (PCPs), Co3(DPyP)3·4DMF (I) and Zn3(DPyP)3·2DMF·4H2O (II). Both PCPs were structurally characterized by X-ray crystallography. Particularly, the central Mn(III) ion in MnCl(DPyP) was transmetallated with Co(II) or Zn(II) ions and the central Co(II) or Zn(II) ions were further coordinated to pyridyl groups of neighboring M(DPyP) (M = Co or Zn) porphyrin complexes. PCPs I and II are isostructural and each 1D double chain interacts with another 1D double chain by multiple hydrogen bonding to stabilize the resulting framework. Therefore, solvent-free 1D double chain PCPs have permanent porosity, and the void volumes of the solvent-free I and II are calculated to be 22.6% and 23.0%, respectively. Gas sorption analysis indicated that I and II exhibited selective adsorption of CO2 at 196 K. Both PCPs exhibited much smaller sorption abilities for N2 (77 K), H2 (77 K), and CH4 (196 K) than CO2 (196 K). Both PCPs exhibited different PXRD patterns when dried at 373 K, which indicated that the framework transformation of the isostructural M3(DPyP)3 type of PCPs strongly depended on the type of central metal ions. PMID:24496095

Kim, Hyun-Chul; Lee, Young Sun; Huh, Seong; Lee, Suk Joong; Kim, Youngmee

2014-04-21

56

Nanoscale coordination polymers exhibiting luminescence properties and NMR relaxivity  

NASA Astrophysics Data System (ADS)

This article presents the first example of ultra-small (3-4 nm) magneto-luminescent cyano-bridged coordination polymer nanoparticles Ln0.333+Gdx3+/[Mo(CN)8]3- (Ln = Eu (x = 0.34), Tb (x = 0.35)) enwrapped by a natural biocompatible polymer chitosan. The aqueous colloidal solutions of these nanoparticles present a luminescence characteristic of the corresponding lanthanides (5D0 --> 7F0-4 (Eu3+) or the 5D4 --> 7F6-2 (Tb3+)) under UV excitation and a green luminescence of the chitosan shell under excitation in the visible region. Magnetic Resonance Imaging (MRI) efficiency, i.e. the nuclear relaxivity, measurements performed for Ln0.333+Gdx3+/[Mo(CN)8]3- nanoparticles show r1p and r2p relaxivities slightly higher than or comparable to the ones of the commercial paramagnetic compounds Gd-DTPA® or Omniscan® indicating that our samples may potentially be considered as a positive contrast agent for MRI. The in vitro studies performed on these nanoparticles show that they maybe internalized into human cancer and normal cells and well detected by fluorescence at the single cell level. They present high stability even at low pH and lack of cytotoxicity both in human cancer and normal cells.This article presents the first example of ultra-small (3-4 nm) magneto-luminescent cyano-bridged coordination polymer nanoparticles Ln0.333+Gdx3+/[Mo(CN)8]3- (Ln = Eu (x = 0.34), Tb (x = 0.35)) enwrapped by a natural biocompatible polymer chitosan. The aqueous colloidal solutions of these nanoparticles present a luminescence characteristic of the corresponding lanthanides (5D0 --> 7F0-4 (Eu3+) or the 5D4 --> 7F6-2 (Tb3+)) under UV excitation and a green luminescence of the chitosan shell under excitation in the visible region. Magnetic Resonance Imaging (MRI) efficiency, i.e. the nuclear relaxivity, measurements performed for Ln0.333+Gdx3+/[Mo(CN)8]3- nanoparticles show r1p and r2p relaxivities slightly higher than or comparable to the ones of the commercial paramagnetic compounds Gd-DTPA® or Omniscan® indicating that our samples may potentially be considered as a positive contrast agent for MRI. The in vitro studies performed on these nanoparticles show that they maybe internalized into human cancer and normal cells and well detected by fluorescence at the single cell level. They present high stability even at low pH and lack of cytotoxicity both in human cancer and normal cells. Electronic supplementary information (ESI) available: TEM images and size distribution histograms, IR and emission spectra, diffraction pattern and HRTEM coupled EDX analysis. See DOI: 10.1039/c0nr00709a

Chelebaeva, Elena; Larionova, Joulia; Guari, Yannick; Ferreira, Rute A. S.; Carlos, Luis D.; Trifonov, Alexander A.; Kalaivani, Thangavel; Lascialfari, Alessandro; Guérin, Christian; Molvinger, Karine; Datas, Lucien; Maynadier, Marie; Gary-Bobo, Magali; Garcia, Marcel

2011-03-01

57

Determining the coordinate dependence of some components of the cubic susceptibility tensor {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous absorbing plate at an arbitrary frequency dispersion  

SciTech Connect

The possibility of unique reconstruction of the spatial profile of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous plate whose medium has a symmetry plane m{sub y} perpendicular to its surface is proved for the first time and the unique reconstruction algorithm is proposed. The amplitude complex coefficients of reflection and transmission (measured in some range of angles of incidence) as well as of conversion of an s-polarised plane signal monochromatic wave into two waves propagating on both sides of the plate make it possible to reconstruct the profile. These two waves result from nonlinear interaction of a signal wave with an intense plane wave incident normally on the plate. All the waves under consideration have the same frequency {omega}, and so its variation helps study the frequency dispersion of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}). For media with additional symmetry axes 2{sub z}, 4{sub z}, 6{sub z}, or {infinity}{sub z} that are perpendicular to the plate surface, the proposed method can be used to reconstruct the profile and to examine the frequency dispersion of about one third of all independent complex components of the tensor {chi}-hat{sup (3)}. (nonlinear-optics phenomena)

Golubkov, A A [Department of Physics, Advanced Educational and Scientific Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Makarov, Vladimir A [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2010-12-29

58

Hydrogen-bonded porous coordination polymers: structural transformation, sorption properties, and particle size from kinetic studies.  

PubMed

Three new coordination polymers, [CoCl2(4-pmna)2]n (1), {[Co(NCS)2(4-pmna)2].2Me2CO}n (2 superset 2Me2CO), and {[Co(4-pmna)2(H2O)2](NO3)2.2CH3OH}n (3 superset 2H2O.2MeOH) (4-pmna = N-(pyridin-4-ylmethyl)nicotinamide), have been synthesized and characterized using single-crystal X-ray diffraction. The cobalt(II) atoms are bridged by 4-pmna ligands in all three compounds to form double-stranded one-dimensional "repeated rhomboid-type" chains with rectangular-shaped cavities. In 1, each chain slips and obstructs the neighboring cavities so that there are no guest-incorporated pores. Both 2 superset 2Me2CO and 3 superset 2H2O.2MeOH do not have such a staggered arrangement and have pores that can be filled with a guest molecule. Compound 3 superset 2H2O.2MeOH traps guest molecules with multiple hydrogen bonds and shows a reversible structural rearrangement during adsorption and desorption. The new crystalline compound, 3, is stabilized by forming hydrogen bonds with the amide moieties of the 4-pmna ligands and was characterized using infrared spectroscopy. The clathration enthalpy of the reaction 3 + 2H2O(l) + 2MeOH(l) <==> 3 superset 2H2O.2MeOH (approximately 35 kJ/mol) was estimated from differential scanning calorimetry data by considering the vaporization enthalpies of H2O and MeOH. The desorption process of 3 superset 2H2O.2MeOH --> 3 follows a single zero-order reaction mechanism under isothermal conditions. The activation energy of ca. 100 kJ/mol was obtained by plotting the logarithm of the reaction time for the same reacted fraction versus the reciprocal of the temperature. Moreover, the distribution of the one-dimensional channels in 3 superset 2H2O.2MeOH was estimated using the observation that the reaction rate is directly proportional to the total sectional area. PMID:17165765

Uemura, Kazuhiro; Saito, Kazuya; Kitagawa, Susumu; Kita, Hidetoshi

2006-12-20

59

Soluble porous coordination polymers by mechanochemistry: from metal-containing films/membranes to active catalysts for aerobic oxidation.  

PubMed

Soluble porous coordination polymers from mechanochemical synthesis are presented through a coordination polymerization between highly contorted, rigid tetraphenol and a broad variety of transition metal ions. These polymers can be easily cast as metal-containing films or freestanding membranes. Importantly, as-made coordination polymers are highly active and stable in the aerobic oxidation of allylic C?H bonds. PMID:25389070

Zhang, Pengfei; Li, Haiying; Veith, Gabriel M; Dai, Sheng

2015-01-01

60

Mixed ligand coordination polymers with flexible bis-imidazole linker and angular sulfonyldibenzoate: Crystal structure, photoluminescence and photocatalytic activity  

NASA Astrophysics Data System (ADS)

Four ternary coordination polymers (CPs) namely, {[Ni(SDB)(BITMB)(H2O)]·H2O}n (CP1), {[Cd(SDB)(BITMB) (H2O)]·(THF)(H2O)}n (CP2), {[Zn2(SDB)2(BITMB)]·(THF)2}n (CP3) and {[Co2(SDB)2(BITMB)]·(Dioxane)3}n (CP4) composed of angular dicarboxylate SDB (4,4'-sulfonyldibenzoate) and N-donor BITMB (1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethyl benzene) have been synthesized by solvothermal reactions and characterized by single crystal X-ray diffraction and other physico-chemical techniques. CP1 possesses one-dimensional ribbon type metal-organic motifs glued together by H-bonds and ?⋯? interactions, whereas CP2-CP4, exhibit non-interpenetrated sql networks supported by weak supramolecular interactions. Structural diversity of these CPs can be attributed to the coordination geometry adopted by the metal nodes, versatile coordination modes of SDB and conformational flexibility of BITMB. Solid state luminescence properties of CP1-CP4 were explored. Photocatalytic performance of all CPs for the decomposition of metanil yellow by dilute hydrogen peroxide in the presence of visible light was also investigated. 25-83% dye removal from aqueous solutions in the presence of CP1-CP4 was observed.

Bisht, Kamal Kumar; Rachuri, Yadagiri; Parmar, Bhavesh; Suresh, Eringathodi

2014-05-01

61

Coordination Polymer: Synthesis, Spectral Characterization and Thermal Behaviour of Starch-Urea Based Biodegradable Polymer and Its Polymer Metal Complexes  

PubMed Central

A starch-urea-based biodegradable coordination polymer modified by transition metal Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) was prepared by polycondensation of starch and urea. All the synthesized polymeric compounds were characterized by Fourier transform-infrared spectroscopy (FT-IR), 1H-NMR spectroscopy, 13C-NMR spectroscopy, UV-visible spectra, magnetic moment measurements, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The results of electronic spectra and magnetic moment measurements indicate that Mn(II), Co(II), and Ni(II) complexes show octahedral geometry, while Cu(II) and Zn(II) complexes show square planar and tetrahedral geometry, respectively. The thermogravimetric analysis revealed that all the polymeric metal complexes are more thermally stable than the parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM standards of biodegradable polymers by CO2 evolution method. PMID:20414461

Malik, Ashraf; Parveen, Shadma; Ahamad, Tansir; Alshehri, Saad M.; Singh, Prabal Kumar; Nishat, Nahid

2010-01-01

62

A novel unexpected seven-coordinated chain-like dysprosium coordination polymer of pyridine-4-carboxylate: structure and photophysical property  

Microsoft Academic Search

One novel dysprosium coordination polymer [Dy(PIC)3(H2O)2]n (HPIC = pyridine-4-carboxylic acid) has been synthesized. X-ray analysis reveals that it forms the chain-like molecular structure through the bridged oxygen atoms of the carbonyl groups. The title coordination polymer crystallizes in the monoclinic system, space group C2\\/c, with lattice parameters: a=20.243(9) Å, b=11.576(5) Å, c=9.834(4) Å, ?=110.601(2)°, V=2078(2) Å3, Dc=1.805 mg\\/m3, Z=4, F(000)=1100,

Bing Yan; Qi-You Xie

2003-01-01

63

Control of structure dimensionality and functional studies of flexible Cu(II) coordination polymers.  

PubMed

Four Cu(II) coordination polymers [Cu(2)(bci)(2)(H(2)O)(2)] x 3 H(2)O (1), [Cu(tciH)(H(2)O)] (2), {[Cu(tci)](2) [Cu(5)(tci)(2) (OH)(2) (H(2)O)(8)]} x 22 H(2)O (3), and [Cu(3)(tci)(2)(py)(4)(H(2)O)(2)] (4) (bciH(2): bis(2-carboxyethyl) isocyanurate; tciH(2): tris(2-carboxyethyl) isocyanurate) were synthesized by using two flexible organic ligands at room temperature. Control synthesis of the compounds showed a variety of structural motifs, namely, one-dimensional (1D) chains (1 and 2), 2D layers with 0D units (3), and 3D frameworks (4). The 1D chain structure of 1 is formed by the bipodal ligand bciH(2) with Cu(II) ions linked by the Cu(2)(CO(2))(4) "paddlewheel" secondary building units (SBUs). The structure of 2 is very similar to 1, where two carboxylic acid groups of the similar tripodal ligand tciH(3) are used to make a 1D chain structure and one carboxylic acid group of the ligand remains protonated. Use of an excess amount of base (NaOH) deprotonated all three carboxylic acid groups to form 3, which contains an anionic 2D sheet structure neutralized by the 0D cationic Cu(5) units. When pyridine was used as base, it also functioned as a co-ligand to make 3D frameworks of 4. Compound 3 showed reversible structural transformations between crystalline and amorphous phases upon dehydration and rehydration. The dehydrated phase showed size and affinity based selective sorption, where MeOH molecules were adsorbed but MeCN and EtOH molecules with similar and larger sizes, respectively, were not adsorbed. The sorption profile of MeOH showed gate-opening phenomenon with a hysteresis profile, which indicates dynamic structural transformations. PMID:19248075

Ghosh, Sujit K; Azhakar, Ramachandan; Kitagawa, Susumu

2009-06-01

64

Metal-controlled assembly tuning the topology and dimensionality of coordination polymers of Ag(I), Cd(II) and Zn(II) with the flexible 2-(1 H-imidazole-1-yl)acetic acid (Hima)  

NASA Astrophysics Data System (ADS)

Three new, inorganic-organic coordination polymers based on a versatile linking unit 2-(1 H-imidazole-1-yl)acetate (ima) and Ag I, Cd II and Zn II ions, exhibiting one to three dimensionalities and different topology structures, have been prepared in water medium and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of AgNO 3 with Hima afforded a neutral one-dimensional (1-D) chains [Ag(ima)] n ( 1) which exhibits a pseudo two-dimensional (2-D) layered architecture through ?-? stacking interaction between imidazole rings and intermolecular Ag⋯Ag interactions. Reaction of CdCl 2 with Hima yielded neutral 2-D coordination polymers [Cd(ima) 2] n ( 2) possessing (6, 3) topology structures, which further stack into 3-D supramolecular networks through C-H⋯O weak interactions. While Zn(NO 3) 2 was used, a non-centric 3-D coordination polymer [Zn(ima) 2] n ( 3) featuring a 3-fold interpenetrating diamondoid net was isolated. Among these polymers, the building block ima anion exhibits different coordination modes. These results indicate that the versatile nature of this flexible ligand, together with the coordination preferences of the metal ions, play a critical role in construction of these novel coordination polymers. The spectral, thermal and SHG (second-harmonic generation) properties of these new materials have also been investigated.

Wang, Yong-Tao; Tang, Gui-Mei; Wu, Yue; Qin, Xu-Yan; Qin, Da-Wei

2007-04-01

65

X-Ray Scattering of One-Dimensional and One-Dimensionally Modulated Structures.  

NASA Astrophysics Data System (ADS)

The Hg-chains in Hg(,3-(delta))AsF(,6) at high temperatures are the only known example of a real physical system for which the lattice dynamics can be accurately described as one-dimensional. The diffuse X-ray scattering by the Hg-chains at high temperatures was studied and compared to the model of independent harmonic chains proposed by Emery and Axe. Its powder scattering lineshape at room temperature is analyzed in a theory developed for independent one-dimensional chains. In both cases, the theories are found to be in quantitative agreement with the experimental data. At low temperatures, interchain couplings produce long range order between chains and generate new Bragg peaks (satellites). Emery-Axe's coupled chains model is in rough qualitative agreement with the observed satellite intensity growth. While satellite intensity has strong temperature and diffraction order dependence, the diffuse sheet intensity remains unchanged down to the lowest accessible temperature. Thus, we include a quantum calculation of 1d structure factor, which has a power law decay at T = 0 due to zero point motion, since an actual study of 1d lattice dynamics in the quantum regime may in fact be possible. Attempts to observe a lock in transition ((delta)(--->)0) at high temperatures have also been made. In the 1d modulated structures, we include: (1) A model calculation of the scattering pattern of a soliton lattice. (2) X-ray scattering study of the commensurate -incommensurate transition in K(,2)SeO(,4), and (3) X-ray scattering study of the structure of the long chain polymer, the trans isomer of polyacetylene, trans-(CH)(,x).

Chen, Cheng-Eng Daniel

1982-03-01

66

One-dimensional staged self-assembly  

E-print Network

We introduce the problem of staged self-assembly of one-dimensional nanostructures, which becomes interesting when the elements are labeled (e.g., representing functional units that must be placed at specific locations). ...

Demaine, Erik D.

67

One-Dimensional Czedli-Type Islands  

ERIC Educational Resources Information Center

The notion of an island has surfaced in recent algebra and coding theory research. Discrete versions provide interesting combinatorial problems. This paper presents the one-dimensional case with finitely many heights, a topic convenient for student research.

Horvath, Eszter K.; Mader, Attila; Tepavcevic, Andreja

2011-01-01

68

pH-responsive robust polymer micelles with metal-ligand coordinated core cross-links.  

PubMed

We report on pH-responsive core-shell polymer micelles with catechol-Fe(3+) coordinated core cross-links, which provide robustness to drug-loaded polymer micelles and allow the facilitated intracellular release of loaded anticancer drugs in response to an endosomal acidic pH. PMID:24643304

Hwang, Gyu Ha; Min, Kyung Hyun; Lee, Hong Jae; Nam, Hye Young; Choi, Gi Hyun; Kim, Byung Joo; Jeong, Seo Young; Lee, Sang Cheon

2014-04-28

69

Crystal structure, infrared spectra and luminescence of a 1D Cd coordination polymer with 4-nitrophthalic acid and 1,10-phenanthroline monohydrate ligands  

NASA Astrophysics Data System (ADS)

A new one-dimensional (1D) coordination polymer, [Cd(NPTA)(1,10-phen)(H2O)] n ( 1) (H2NPTA = 4-nitrophthalic acid; 1,10-phen = 1,10-phenanthroline monohydrate), has been synthesized under hydrothermal conditions and characterized by elemental analysis, single-crystal X-ray diffraction, solid state emission spectra, FT-IR spectra, and thermogravimetric analyses. The compound belongs to triclinic system with space group , and exhibits a one-dimensional linear chain. Each Cd with a strongly distorted octahedral coordination geometry is six-coordinated by two N atoms from one 1,10-phenanthroline ligand, three O atoms from two carboxylate groups of two different NPTA2- ligands and one O atoms from lattice water. Layer supramolecular architecture is formed by medium ?-? stacking interactions between two neighboring phenanthroline rings from two independent linear chains. Studies on luminescent property of 1 exhibit the solid state emission originating from an intra ligand ? ? ?* transition of NPTA2- ligand.

Han, Li-Juan; Kong, Ya-Jie; Sheng, Ning

2015-01-01

70

Influence of aminopyrimidyl derivatives on the supramolecular architectures and abundant nonvalent interactions of silver 5-nitroisophthalate coordination polymers  

NASA Astrophysics Data System (ADS)

Two 5-nitroisophthalate silver(I) coordination polymers with 2-aminopyrimidyl derivatives, namely [Ag 2(apym) 1.5(nipa)·H 2O] n ( 1) and [Ag 2(dmapym) 2(nipa)] n ( 2) were synthesized and characterized by single-crystal X-ray analysis (apym = 2-aminopyrimidine, dmapym = 2-amino-4,6-dimethylprimidine, H 2nipa = 5-nitroisophthalic acid). Complex 1 possesses a one-dimensional (1D) structure built from rhombic [Ag 4(apym) 2(nipa) 2] second building units (SBUs). The uncoordinated O nitro is involved in the significant lone-pair (lp)⋯? interaction with the benzene ring of nipa. Complex 2 possesses a two-dimensional (2D) structure in which dmapym ligands show two different coordination modes, monodentate and bidentate, respectively. Moreover, 2 shows abundant nonvalent interactions, such as lp(O carboxyl)⋯?, ?⋯?, C-H⋯? interactions and hydrogen-bonding simultaneously. 1 and 2 also exhibit diverse structure motifs due to the effects of substituent methyl groups. The photoluminescence properties of these complexes also were examined.

Sun, Di; Luo, Geng-Geng; Zhang, Na; Wei, Zhan-Hua; Yang, Cheng-Feng; Xu, Qin-Juan; Huang, Rong-Bin; Zheng, Lan-Sun

2010-04-01

71

Syntheses, crystal structures and luminescent properties of two new 1D d10 coordination polymers constructed from 2,2?-bibenzimidazole and 1,4-benzenedicarboxylate  

NASA Astrophysics Data System (ADS)

Two novel interesting d10 metal coordination polymers, [Zn(H 2bibzim)(BDC)] n ( 1) and [Cd(H 2bibzim)(BDC)] n ( 2) [H 2bibzim=2,2'-bibenzimidazole, BDC=1,4-benzenedicarboxylate] have been synthesized under solvothermal conditions and structurally characterized. Both 1 and 2 are constructed from infinite neutral zigzag-like one-dimensional (1D) chains. The ?- ? interactions and interchain hydrogen-bonding interactions further extend the 1D arrangement to generate a 3D supramolecular architecture for 1 and 2. Both complexes have high thermal stability and display strong blue fluorescent emissions in the solid state upon photo-excitation at 365 nm at room temperature. They are the first two examples that 2,2'-bibenzimidazole has been introduced into the d10 coordination polymeric framework.

Wen, Lili; Li, Yizhi; Dang, Dongbin; Tian, Zhengfang; Ni, Zhaoping; Meng, Qingjin

2005-11-01

72

1D Cu(II) coordination polymer derived from 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonate chelator and pyrazine spacer  

NASA Astrophysics Data System (ADS)

Reaction of 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonic acid (H2L) with copper(II) nitrate hydrate in the presence of pyrazine (pz) in methanol affords the coordination polymer [Cu2(?-L)2(H2O)2(?-pz)]n (1), where the bidentate pz molecule links two Cu(II) centres of two different dimeric units, giving rise to a one-dimensional chain. The dimeric unit [Cu2(?-L)2(H2O)2] consists of two distorted octahedral Cu(II) centres connected via oxygen atoms of the sulfo group of the bridging L2- ligand. The extensive hydrogen bonding between the coordinated water and pz molecules leads to the formation of a supramolecular 3D associate. Compound 1 has been characterized by elemental analysis, ESI-MS, IR spectroscopy and single-crystal X-ray diffraction analysis.

Mahmudov, Kamran T.; Haukka, Matti; Sutradhar, Manas; Mizar, Archana; Kopylovich, Maximilian N.; Pombeiro, Armando J. L.

2013-02-01

73

A metal-organic coordination polymer based on 1,2-bis(diphenylphosphino)ethane dioxide: Synthesis, crystal structure and fluorescence of [ZnI 2{Ph 2P(O)CH 2CH 2-P(O)Ph 2}] n  

Microsoft Academic Search

A zinc coordination polymer, [ZnI2{Ph2P(O)-CH2CH2-P(O)Ph2}]n (1), has been prepared, which features a one-dimensional concavo-convex chain with alternative ZnI2 and 1,2-bis(diphenylphosphino)ethane dioxide (dppeO2) moieties. The dppeO2 ligand adopts the bridging coordination mode between two zinc atoms.

Xiaoqing Liu; Xiao-Juan Yang; Peiju Yang; Yanyan Liu; Biao Wu

2009-01-01

74

A mixed valent heterometallic Cu(II)/Na(I) coordination polymer with sodium-phenyl bonds.  

PubMed

A mixed valent heterometallic Cu(II)/Na(I) coordination polymer (1) is generated by the reaction of a Schiff base ligand, (6,6'-(1E,1'E)-(2-hydroxypropane-1,3-diyl)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(2-methoxyphenol)) with copper(II) acetate and sodium perchlorate. In addition to the presence of alcohol oxygen-sodium coordination bonds, the single crystal X-ray structure reveals that the 1D coordination polymer is stabilised by the formation of phenyl-sodium ?2-bonds, face-to-face ?-? contacts and Cu-? interactions. PMID:24549373

Datta, Amitabha; Das, Kuheli; Massera, Chiara; Clegg, Jack K; Sinha, Chittaranjan; Huang, Jui-Hsien; Garribba, Eugenio

2014-04-14

75

Dimensional modulation and magnetic properties of triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates  

NASA Astrophysics Data System (ADS)

Five new metal-organic coordination polymers {[Cu3(?2-OH)2(atrz)2(nph)2(H2O)2]·2H2O}n (1), {[Cu2(?3-OH)(atrz)(1,2,4-btc)]·2H2O}n (2), {[Cu2(?3-OH)(atrz)(1,2,4-btc)(H2O)]·H2O}n (3), [Cu(dth)0.5(nph)(H2O)]n (4) and [Cu(dth)(Hnip)2]n (5) [atrz=4-amino-1,2,4-triazole, dth=N,N'-di(4H-1,2,4-triazole)hexanamide, H2nph=3-nitrophthalic acid, 1,2,4-H3btc=1,2,4-benzenetricarboxylic acid and H2nip=5-nitroisophthalic acid] were hydrothermally synthesized and structurally characterized. Polymer 1 shows a one-dimensional (1D) chain. Polymers 2 and 3 exhibit similar tetranuclear CuII4 cluster-based three-dimensional (3D) frameworks with the same components. Polymer 4 possesses a 3D framework with a 412·63-pcu topology. Polymer 5 displays a 3D framework with a 44·610·8-mab topology. The magnetic properties of 1-4 were investigated.

Zhang, Ju-Wen; Zhao, Wei; Lu, Qi-Lin; Luan, Jian; Qu, Yun; Wang, Xiu-Li

2014-04-01

76

One-dimensional Gromov minimal filling problem  

NASA Astrophysics Data System (ADS)

The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

Ivanov, Alexandr O.; Tuzhilin, Alexey A.

2012-05-01

77

One-dimensional Gromov minimal filling problem  

SciTech Connect

The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

Ivanov, Alexandr O; Tuzhilin, Alexey A

2012-05-31

78

One-dimensional ablation in multiwire arrays.  

SciTech Connect

The main physical processes responsible for plasma ablation in multiwire Z pinches are considered via eigensolutions to one-dimensional steady state magnetohydrodynamics. A double scale-length structure of the plasma accelerating layer is demonstrated. The width of the resistive scale-length that defines the current layer structure is significantly larger than the thermal scale-length, where transport of energy toward the cores and plasma pressure play important roles. The transport of energy is provided mainly by radiation, though electron thermal conduction is also important very close to the plasma-core interface. Another type of solution of the steady state problem is revealed, when local Ohmic heating is important down to the interface. Selection between these two types of solutions is considered from multiple points of view. Although the one-dimensional problem is mainly considered in this paper, it is shown how the one-dimensional results may help to understand results of two-dimensional models.

Oliver, Bryan Velten; Mehlhorn, Thomas Alan; Sasorov, Pavel V. (Institute of theoretical and experimental physics, Moscow, Russia.); Yu, Edmund P.

2007-08-01

79

One-dimensional ablation in multiwire arrays  

SciTech Connect

The main physical processes responsible for plasma ablation in multiwire Z pinches are considered via eigensolutions to one-dimensional steady state magnetohydrodynamics. A double scale-length structure of the plasma accelerating layer is demonstrated. The width of the resistive scale-length that defines the current layer structure is significantly larger than the thermal scale-length, where transport of energy toward the cores and plasma pressure play important roles. The transport of energy is provided mainly by radiation, though electron thermal conduction is also important very close to the plasma-core interface. Another type of solution of the steady state problem is revealed, when local Ohmic heating is important down to the interface. Selection between these two types of solutions is considered from multiple points of view. Although the one-dimensional problem is mainly considered in this paper, it is shown how the one-dimensional results may help to understand results of two-dimensional models.

Sasorov, P. V. [Institute of Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Oliver, B. V.; Yu, E. P.; Mehlhorn, T. A. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1193 (United States)

2008-02-15

80

One-dimensional location area design  

Microsoft Academic Search

Location management cost in a wireless network is expressed in this work as the sum of signaling cost due to paging and signaling cost due to registration. We introduce and compare a heuristic method and an asymptotic method for selecting a disjoint partition of a one-dimensional service area to minimize location management costs. In special cases for which the best

Cem U. Saraydar; Owen E. Kelly; Christopher Rose

2000-01-01

81

One-Dimensional Oscillator in a Box  

ERIC Educational Resources Information Center

We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results…

Amore, Paolo; Fernandez, Francisco M.

2010-01-01

82

The One-Dimensional Wave Equation  

NSDL National Science Digital Library

Created by Lang Moore for the Connected Curriculum Project, the purpose of this module is to study solutions of initial/boundary value problems for the one-dimensional wave equation. This is one of a much larger set of learning modules hosted by Duke University.

Moore, Lang

2010-08-19

83

Synthesis, structure and DFT study of a chelidamic acid based Cu coordination polymer: On the importance of ?-? interactions and hexameric water clusters  

NASA Astrophysics Data System (ADS)

One-dimensional coordination polymer, i.e., {(Hampy)[Cu(chel)(H2O)]?2H2O}n (1, ampy = 2-amino-6-methylpyridine, H3chel = chelidamic acid), has been synthesized and characterized by elemental analysis, IR spectroscopy, solution studies and X-ray single-crystal diffraction. In the monomeric unit of compound 1 the metal center exhibits a distorted square-pyramidal coordination sphere. The Cu(II) ion is coordinated to chelidamic acid and water. These monomers are interlinked generating a 1D polymer by means of the para hydroxyl group of the ligand. Protonated 2-amino-6-methylpyridine rings act as counter cations. The crystal lattice is aggregated through intermolecular interactions, such as electrostatic attraction, N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonding and aromatic ? stacking interactions. Hydrogen bond interactions between the water molecules led to formation of six-membered rings with chair conformation. These assemblies are described and analyzed by means of density functional theory (DFT) calculations since they play an important role in the construction of three-dimensional supramolecular frameworks.

Mirzaei, Masoud; Eshtiagh-Hosseini, Hossein; Karrabi, Zahra; Notash, Behrouz; Bauzá, Antonio; Frontera, Antonio

2015-01-01

84

Selective sorption of oxygen and nitric oxide by an electron-donating flexible porous coordination polymer.  

PubMed

Porous coordination polymers are materials formed from metal ions that are bridged together by organic linkers and that can combine two seemingly contradictory properties-crystallinity and flexibility. Porous coordination polymers can therefore create highly regular yet dynamic nanoporous domains that are particularly promising for sorption applications. Here, we describe the effective selective sorption of dioxygen and nitric oxide by a structurally and electronically dynamic porous coordination polymer built from zinc centres and tetracyanoquinodimethane (TCNQ) as a linker. In contrast to a variety of other gas molecules (C(2)H(2), Ar, CO(2), N(2) and CO), O(2) and NO are accommodated in its pores. This unprecedented preference arises from the concerted effect of the charge-transfer interaction between TCNQ and these guests, and the switchable gate opening and closing of the pores of the framework. This system provides further insight into the efficient recognition of small gas molecules. PMID:20651724

Shimomura, Satoru; Higuchi, Masakazu; Matsuda, Ryotaro; Yoneda, Ko; Hijikata, Yuh; Kubota, Yoshiki; Mita, Yoshimi; Kim, Jungeun; Takata, Masaki; Kitagawa, Susumu

2010-08-01

85

A luminescent coordination polymer based on bisterpyridyl ligand containing o-carborane: two tunable emission modes.  

PubMed

We designed a novel ditopic bisterpyridyl ligand containing o-carborane that can construct a coordination polymer by complexation with metal ions. Through the use of Sonogashira-Hagihara coupling, the desired ligand molecule was successfully synthesized. Addition of Zn(II) ions rapidly underwent the generation of a fluorescent coordination polymer, which was confirmed by (1)H NMR, UV-vis, and fluorescent titration experiments. Furthermore, the electronic structure of the bisterpyridyl ligand molecules was drastically changed upon the complexation with metal ions. The obtained coordination polymer showed light blue emission derived from the intraligand charge transfer (ILCT) state, whereas a bare ligand molecule exhibited yellowish-green aggregation-induced emission (AIE) in a poor solvent such as water, because of the variable C-C bond in o-carborane. PMID:21258739

Kokado, Kenta; Chujo, Yoshiki

2011-03-01

86

The one dimensional Coulomb lattice fluid capacitor  

E-print Network

The one dimensional Coulomb lattice fluid in a capacitor configuration is studied. The model is formally exactly soluble via a transfer operator method within a field theoretic representation of the model. The only interactions present in the model are the one dimensional Coulomb interaction between cations and anions and the steric interaction imposed by restricting the maximal occupancy at any lattice site to one particle. Despite the simplicity of the model, a wide range of intriguing physical phenomena arise, some of which are strongly reminiscent of those seen in experiments and numerical simulations of three dimensional ionic liquid based capacitors. Notably we find regimes where over-screening and density oscillations are seen near the capacitor plates. The capacitance is also shown to exhibit strong oscillations as a function of applied voltage. It is also shown that the corresponding mean field theory misses most of these effects. The analytical results are confirmed by extensive numerical simulations.

Vincent Demery; David S. Dean; Thomas C. Hammant; Ronald R. Horgan; Rudolf Podgornik

2012-06-21

87

A statistical formulation of one-dimensional electron fluid turbulence  

NASA Technical Reports Server (NTRS)

A one-dimensional electron fluid model is investigated using the mathematical methods of modern fluid turbulence theory. Non-dissipative equilibrium canonical distributions are determined in a phase space whose co-ordinates are the real and imaginary parts of the Fourier coefficients for the field variables. Spectral densities are calculated, yielding a wavenumber electric field energy spectrum proportional to k to the negative second power for large wavenumbers. The equations of motion are numerically integrated and the resulting spectra are found to compare well with the theoretical predictions.

Fyfe, D.; Montgomery, D.

1977-01-01

88

One-dimensional s-p superlattice  

E-print Network

The physics of one dimensional optical superlattices with resonant $s$-$p$ orbitals is reexamined in the language of appropriate Wannier functions. It is shown that details of the tight binding model realized in different optical potentials crucially depend on the proper determination of Wannier functions. We discuss the properties of a superlattice model which quasi resonantly couples $s$ and $p$ orbitals and show its relation with different tight binding models used in other works.

Wojciech Ganczarek; Michele Modugno; Giulio Pettini; Jakub Zakrzewski

2014-06-23

89

Functionalized lanthanide coordination polymer nanoparticles for selective sensing of hydrogen peroxide in biological fluids.  

PubMed

Lanthanide coordination polymers have recently emerged as very fascinating sensing materials due to their tunable structures and unique optical properties. However, a major problem concerning the applications of lanthanide coordination polymers for fluorescent sensing is their unselective recognition to analytes. In this work, a direct post-modification strategy was employed to prepare functionalized lanthanide coordination polymer nanoparticles (Phe/Tb-CPBA CPNPs) with specific response ability to hydrogen peroxide (H2O2) by using phenylalanine (Phe) as bridging ligands, terbium ions (Tb(3+)) as metal nodes and carboxyphenylboronic acids (CPBAs) as guest ligands. Phe/Tb-CPBA CPNPs emit a strong green fluorescence due to the removal of coordinated water molecules and the sensitization effect of CPBA. Upon the addition of H2O2, however, the quenched fluorescence of Phe/Tb-CPBA CPNPs can be observed owing to an intramolecular charge transfer effect. This finding led to a method for the quantitation of H2O2 in the 6 ?M to 1 mM concentration range and with a detection limit at 2 ?M. Because of the chemoselective H2O2-mediated oxidative deboronation, Phe/Tb-CPBA CPNPs as fluorescent sensors exhibit excellent selectivity to H2O2. Furthermore, Phe/Tb-CPBA CPNPs were successfully used to measure the level of H2O2 in urine samples and showed satisfactory results. We envision that the presented strategy could be extended to design other functionalized coordination polymers with desired functions for various biomedical applications. PMID:25195570

Tan, Hongliang; Ma, Chanjiao; Li, Qian; Wang, Li; Xu, Fugang; Chen, Shouhui; Song, Yonghai

2014-11-01

90

Supramolecular polymers with tunable topologies via hierarchical coordination-driven self-assembly and hydrogen bonding interfaces  

PubMed Central

A powerful strategy to obtain complex supramolecular materials is the bottom-up construction of noncovalently bound materials by hierarchical self-assembly. This assembly process involves stepwise, uniform increases to the architectural complexity of a substrate, starting from discrete precursors and growing in dimensionality through controlled reactivity to a final product. Herein, two orthogonal processes are exploited: coordination-driven self-assembly and hydrogen bonding. The former relies on the predictable formation of metal–ligand bonds wherein the directionalities of the rigid precursors used determines the structural outcome. The latter uses 2-ureido-4-pyrimidinone interfaces that are structurally robust by virtue of the quadruple hydrogen bonding that can occur between subunits. By combining these two processes into a single system, it is possible to generate hierarchical materials that preserve the attractive tunability associated with discrete supramolecular coordination complexes. For instance, the synthesis of a one-dimensional chain comprising linked metalla-rhomboids is readily adapted to a 2D cross-linked hexagonal network by simply selecting a different metal acceptor precursor as an assembly component. The specific interactions between subunits, in this case platinum(II)-pyridyl bonds and the quadruple H-bonding of ureidopyrimidinone, are unchanged, establishing a unique strategy to obtain supramolecular polymers with marked topological differences with minimal synthetic redesign. In addition, the structural rigidity imposed by the inclusion of the platinum metallacycles serves to minimize the formation of cyclic oligomers, increasing the efficacy of formation and improving the properties of the resultant materials. Furthermore, this study taps the potential of organoplatinum(II) metallacycles in materials science. PMID:24019475

Yan, Xuzhou; Li, Shijun; Pollock, James Bryant; Cook, Timothy R.; Chen, Jianzhuang; Zhang, Yanyan; Ji, Xiaofan; Yu, Yihua; Huang, Feihe; Stang, Peter J.

2013-01-01

91

A Redox-Active Two-Dimensional Coordination Polymer: Preparation of Silver and Gold Nanoparticles and Crystal  

E-print Network

, diameter) nanoparticles were formed by the redox reactions between Ni(II) ions incorporated in 1 and metal reaction. We also reported that the redox-active coordination polymer produced silver nanoparticles of 3 nmA Redox-Active Two-Dimensional Coordination Polymer: Preparation of Silver and Gold Nanoparticles

Paik Suh, Myunghyun

92

One dimensional electromagnetic waves on flat surfaces  

NASA Astrophysics Data System (ADS)

We show that one-dimensional electromagnetic waves can be constrained to propagate along a join between two thin sheets when one surface supports transverse magnetic polarized surface waves and the other supports transverse electric polarized surface waves. We calculate the dispersion relation of these modes and show that they are exceptionally tightly confined to the join, with characteristic decay lengths an order of magnitude smaller than the surface waves supported by each individual surface. We give an example of a metasurface implementation where low frequency instances of such waves may be observed.

Horsley, S. A. R.; Hooper, I. R.

2014-10-01

93

Point interactions in acoustics: one dimensional models  

E-print Network

A one dimensional system made up of a compressible fluid and several mechanical oscillators, coupled to the acoustic field in the fluid, is analyzed for different settings of the oscillators array. The dynamical models are formulated in terms of singular perturbations of the decoupled dynamics of the acoustic field and the mechanical oscillators. Detailed spectral properties of the generators of the dynamics are given for each model we consider. In the case of a periodic array of mechanical oscillators it is shown that the energy spectrum presents a band structure.

C. Cacciapuoti; R. Figari; A. Posilicano

2005-04-28

94

A mixed-valence copper coordination polymer generated by hydrothermal metal/ligand redox reactions  

E-print Network

A mixed-valence copper coordination polymer generated by hydrothermal metal/ligand redox reactions in preparing highly stable, infinite metal­ligand frameworks.2 It has been found that in situ reactions,3 such as ligand oxidative coupling, hydrolysis, substitution and redox process of copper, can occur under hydro

Li, Jing

95

Sonochemical syntheses of two new flower-like nano-scale high coordinated lead(II) supramolecular coordination polymers.  

PubMed

Two new neutral nano flower polymeric lead(II) coordination compounds, [Pb(tmph)(?-SCN)?]n (1) and [Pb(tmph)(?-NO?)?]n (2), [tmph=3,4,7,8-tetramethyl-1,10-phenanthroline], have been synthesized by a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses. SEM image shows the nano flower morphology for the products. Single-crystal X-ray studies show that the overall structure of the both 1 and 2 are 1D double chain net-like coordination polymers. Compound 1 has a very rare bridging cyanato pathway; a tetra dentate bridging between four Pb(II) centers. 1D double chains of compounds 1 and 2 further extended into two-dimensional (2D) and three dimensional (3D) supramolecular structures by strong ?-? directional intermolecular interactions, respectively. PMID:25453214

Hanifehpour, Younes; Safarifard, Vahid; Morsali, Ali; Mirtamizdoust, Babak; Joo, Sang Woo

2015-03-01

96

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)

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.

Fan, Le-Qing; Chen, Yuan; Wu, Ji-Huai; Huang, Yun-Fang

2011-04-01

97

Temperature-dependent in situ ligand cyclization via C?C coupling and formation of a spin-crossover iron(II) coordination polymer.  

PubMed

The reaction of N(1),N(2)-bis(pyridin-4-ylmethylene)ethane-1,2-diamine (L) with Fe(NCS)(2) under various temperatures gave rise to three iron(II) coordination polymers, namely, one-dimensional [Fe(L')(NCS)(2)] (1), two-dimensional [Fe(L)(2)(NCS)(2)]·H(2)O (2), and one-dimensional [Fe(L)(2)(NCS)(2)]·2CH(2)Cl(2)·4MeOH (3). The formation of 1 involved an in situ C?C coupling reaction, L to L' [L' = 5,6-di(pyridin-4-yl)-1,2,3,4-tetrahydropyrazine], which was catalyzed by cyanide ions decomposed from thiocyanates; the manganese(II) (1a) and zinc(II) (1b) analogues of 1 were also synthesized for comparison. Magnetic studies showed that complex 1 underwent a pressure-dependent one-step incomplete spin transition whereas complexes 2 and 3 were paramagnetic in the whole temperature range. PMID:21186819

Yang, Feng-Lei; Tao, Jun; Huang, Rong-Bin; Zheng, Lan-Sun

2011-02-01

98

Aperiodicity in one-dimensional cellular automata  

SciTech Connect

Cellular automata are a class of mathematical systems characterized by discreteness (in space, time, and state values), determinism, and local interaction. A certain class of one-dimensional, binary site-valued, nearest-neighbor automata is shown to generate infinitely many aperiodic temporal sequences from arbitrary finite initial conditions on an infinite lattice. The class of automaton rules that generate aperiodic temporal sequences are characterized by a particular form of injectivity in their interaction rules. Included are the nontrivial linear'' automaton rules (that is, rules for which the superposition principle holds); certain nonlinear automata that retain injectivity properties similar to those of linear automata; and a wider subset of nonlinear automata whose interaction rules satisfy a weaker form of injectivity together with certain symmetry conditions. A technique is outlined here that maps this last set of automata onto a linear automaton, and thereby establishes the aperiodicity of their temporal sequences. 12 refs., 3 figs.

Jen, E.

1990-01-01

99

Three one-dimensional structural heating programs  

NASA Technical Reports Server (NTRS)

Two computer programs for calculating profiles in a ten-element structure consisting of up to ten materials are presented, along with a third program for calculating the mean temperature for a payload container placed in an orbiting vehicle cargo bay. The three programs are related by the sharing of a common analytical technique; the energy balance is based upon one-dimensional heat transfer. The first program, NQLDW112, assumes a non-ablating surface. NQLDW117 is very similar but allows the outermost element to ablate. NQLDW040 calculates an average temperature profile through an idealized model of the real payload cannister and contents in the cargo bay of an orbiting vehicle.

Wing, L. D.

1978-01-01

100

One-dimensional magnetopolymeric nanostructures with tailored sizes.  

PubMed

Ultra-high aspect ratio nanofibers composed of poly(vinyl alcohol) and CoFe(2)O(4) nanoparticles (PVA/CoFe(2)O(4)) and moderate aspect ratio nanofibers composed of poly(vinyl chloride) and Fe(3)O(4) nanoparticles (PVC/Fe(3)O(4)) have been prepared. Magnetopolymeric one-dimensional (1D) nanostructures with any diameter and length can be prepared by template synthesis using anodic aluminum oxide (AAO) followed by the replication methods presented in this work. These replication methods are very effective, and allow the nanomoulding of any polymer-nanoparticle 1D composite. A first magnetic characterization of the nanostructured composites reveals a modest magnetic anisotropy. The development of magnetopolymeric nanofibers with adjusted length and diameter opens new opportunities in a wide range of applications. PMID:21825668

Martín, J; Vázquez, M; Hernández-Vélez, M; Mijangos, C

2008-04-30

101

Nicotine molecularly imprinted polymer: synergy of coordination and hydrogen bonding.  

PubMed

Two new bis(2,2'-bithienyl)methane derivatives, one with the zinc phthalocyanine substituent (ZnPc-S16) and the other with the 2-hydroxyethyl substituent (EtOH-S4), were synthesized to serve as functional monomers for biomimetic recognition of nicotine (Nic) by molecular imprinting. Formation of a pre-polymerization complex of the Nic template with ZnPc-S16 and EtOH-S4 was confirmed by both the high negative Gibbs free energy gain, ?G = -115.95 kJ/mol, calculated using the density functional theory at the B3LYP/3-21G* level, and the high stability constant, Ks = 4.67 × 10(5) M(-1), determined by UV-vis titration in chloroform. A solution of this complex was used to deposit a Nic-templated molecularly imprinted polymer (MIP-Nic) film on an Au electrode of a quartz crystal resonator of EQCM by potentiodynamic electropolymerization. The imprinting factor was as high as ~9.9. Complexation of the Nic molecules by the MIP cavities was monitored with X-ray photoelectron spectroscopy (XPS), as manifested by a negative shift of the binding energy of the Zn 2p3/2 electron of ZnPc-S16 after Nic templating. For sensing applications, simultaneous chronoamperometry (CA) and piezoelectric microgravimetry (PM) measurements were performed under flow-injection analysis conditions. The limit of detection of the CA and PM chemosensing was as low as 40 and 12 µM, respectively. Among them, the CA chemosensing was more selective to the cotinine and myosmine interferences due to the 1.10 V vs. Ag/AgCl discriminating potential of nicotine electro-oxidation applied. Differences in selectivity to the analyte and interferences were interpreted by modeling complexation of Nic and, separately, each of the interferences with a "frozen" MIP-Nic molecular cavity. PMID:25441415

Huynh, Tan-Phat; B K C, Chandra; Sosnowska, Marta; Sobczak, Janusz W; Nesterov, Vladimir N; D'Souza, Francis; Kutner, Wlodzimierz

2015-02-15

102

Five 8-hydroxyquinolinate-based coordination polymers with tunable structures and photoluminescent properties for sensing nitroaromatics.  

PubMed

Using two 8-hydroxyquinolinate ligands (L1-MOM and L2-MOM) containing 3-pyridyl or 4-pyridyl groups, five novel coordination polymers, namely, [Zn3(L1)6] (1), [Zn(L1)2]·2MeOH (2), [Zn(L2)2] (3), [Cd(L2)2] (4), and [Cd4(L1)6]·13H2O (5), were synthesized and characterized by a variety of techniques. Single-crystal X-ray structures have revealed that these coordination polymers exhibit a structural diversification due to the different choices of metal salts and the effect of pyridyl nitrogen position. Compounds 1-5 exhibited different fluorescence emissions and lifetimes upon excitation in the solid state. The sensing behavior of these polymers was also investigated upon exposure to vapors of various nitroaromatic molecules (analytes). The results show that all five polymers are capable of sensing these nitroaromatic molecules in the vapor phase through fluorescence quenching. Interestingly, 3 exhibits superior sensitivity to the analytes in comparison with other polymers. 2-Nitrotoluene quenches the emission of 3 by as much as 96%. PMID:25367871

Zhang, Liyan; Sun, Liying; Li, Xinyuan; Tian, Yulan; Yuan, Guozan

2015-01-01

103

Novel 3D bismuth-based coordination polymers: Synthesis, structure, and second harmonic generation properties  

SciTech Connect

Two new 3D bismuth containing coordination polymers are reported along with their single crystal structures and SHG properties. Compound 1: Bi{sub 2}O{sub 2}(pydc) (pydc=pyridine-2, 5-dicarboxylate), crystallizes in the monoclinic, polar space group, P2{sub 1} (a=9.6479(9) A, b=4.2349(4) A, c=11.9615(11) A, {beta}=109.587(1) Degree-Sign ), which contains Bi{sub 2}O{sub 2} chains that are connected into a 3D structure via the pydc ligands. Compound 2: Bi{sub 4}Na{sub 4}(1R3S-cam){sub 8}(EtOH){sub 3.1}(H{sub 2}O){sub 3.4} (1R3S cam=1R3S-camphoric acid) crystallizes in the monoclinic, polar space group, P2{sub 1} (a=19.0855(7) A, b=13.7706(5) A, c=19.2429(7) A, {beta}=90.701(1) Degree-Sign ) and is a true 3D coordination polymer. These are two example of SHG compounds prepared using unsymmetric ligands (compound 1) or chiral ligands (compound 2), together with metals that often exhibit stereochemically-active lone pairs, such as Bi{sup 3+}, a synthetic approach that resulted in polar, non-centrosymmetric, 3D metal-organic coordination polymer. - Graphical Abstract: Structures of two new, polar, 3D Bismuth(III)-based coordination polymers: Bi{sub 2}O{sub 2}(pydc) (compound 1), and Bi{sub 4}Na{sub 4}(1R3S-cam){sub 8}(EtOH){sub 3.1}(H{sub 2}O){sub 3.4} (compound 2). Highlights: Black-Right-Pointing-Pointer New, polar, 3D Bismuth(III)-based coordination polymers. Black-Right-Pointing-Pointer First polar bismuth-based coordination polymers synthesized via a 'hybrid' strategy. Black-Right-Pointing-Pointer Combination of stereochemically-active lone pairs and unsymmetrical or chiral ligands. Black-Right-Pointing-Pointer Synthesis of class C-SHG materials based on Kurtz-Perry categories.

Wibowo, Arief C.; Smith, Mark D. [Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States)] [Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States); Yeon, Jeongho; Halasyamani, P. Shiv [Department of Chemistry, University of Houston, 136 Fleming Building, Houston, TX 77204-5003 (United States)] [Department of Chemistry, University of Houston, 136 Fleming Building, Houston, TX 77204-5003 (United States); Loye, Hans-Conrad zur, E-mail: zurloye@mail.chem.sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States)

2012-11-15

104

A coordination polymer of manganese (III) porphyrinate with right-handed helicity and opticity  

NASA Astrophysics Data System (ADS)

A first example of 1D coordination polymer [MnTHPP·H 2O·(DMF) 2 ( 1)] with right-handed helicity and opticity was successfully assembled. Crystal analyses indicate that the right-handed helical assembly is based on coordination bonds from peripheral to center, associating with the saddle distortion of the molecular planes. In its crystal architecture, MnTHPP [manganese (III) ion coordinated by 5,10,15,20-tetra(4-hydroxyphenyl) porphyrin] molecules were ligated each other via the axial coordination between -PhO - ? Mn III (peripheral to center model, from the peripherally deprotonated hydroxyphenyl to the central metal of the neighbor molecule) to construct the right-handed helices, and the helices are sustained by plentiful hydrogen bonding. Meanwhile DMF molecules are entrapped within the voids among the helices. This is a rare example of the multiporphyrin arrays with right-handed helices bearing opticity.

Yang, Jun-Wei; Zhang, Jing; Yan, Yan; Huang, Xiao-Chun; Tong, Shan-Ling

2010-07-01

105

Syntheses, structures and photoelectric properties of a series of Cd(II)/Zn(II) coordination polymers and coordination supramolecules  

SciTech Connect

Five Cd(II)/Zn(II) complexes [Cd(1,2-bdc)(pz){sub 2}(H{sub 2}O)]{sub n} (1), [Cd1Cd2(btec)(H{sub 2}O){sub 6}]{sub n} (2), [Cd(3,4-pdc) (H{sub 2}O)]{sub n} (3), [Zn(2,5-pdc)(H{sub 2}O){sub 4}]{center_dot}2H{sub 2}O (4) and {l_brace} [Zn(2,5-pdc)(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O{r_brace} {sub n} (5) (H{sub 2}bdc=1,2-benzenedicarboxylic acid, pz=pyrazole, H{sub 4}btec=1,2,4,5-benzenetetracarboxylic acid, H{sub 2}pdc=pyridine-dicarboxylic acid) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, surface photovoltage spectroscopy, XRD, TG analysis, IR and UV-vis spectra and elemental analysis. Structural analyses show that complexes 1-3 are 1D, 2D and 3D Cd(II) coordination polymers, respectively. Complex 4 is a mononuclear Zn(II) complex. Complex 5 is a 3D Zn(II) coordination polymer. The surface photoelectric properties of complexes were investigated by SPS. The results indicate that all complexes exhibit photoelectric responses in the range of 300-600 nm, which reveals that they all possess certain photoelectric conversion properties. By the comparative analyses, it can be found that the species and coordination micro-environment of central metal ion, the species and property of ligands affect the intensity and scope of photoelectric response. - Graphical abstract: Five Cd(II)/Zn(II) complexes have been hydrothermally synthesized and characterized. The photoelectric properties were studied with SPS. The species and coordination micro-environment of central metal ion, the species and property of ligands all affect the photoelectric responses. Highlights: Black-Right-Pointing-Pointer Five Cd/Zn complexes have been synthesized and characterized. Black-Right-Pointing-Pointer The SPS results indicate they possess obvious photoelectric conversion property. Black-Right-Pointing-Pointer The species and coordination environment of central metal ion affect SPS. Black-Right-Pointing-Pointer The species and property of ligands affect SPS. Black-Right-Pointing-Pointer By the energy-band theory and the crystal filed theory, the SPS are analyzed and assigned.

Jin Jing; Han Xiao; Meng Qin; Li Dan; Chi Yuxian [School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Niu Shuyun, E-mail: syniu@sohu.com [School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China)

2013-01-15

106

Detailed features of one-dimensional detonations  

NASA Astrophysics Data System (ADS)

The oscillation mechanism and reignition process of one-dimensional unsteady detonations are numerically studied using a one-step chemical reaction model governed by Arrhenius kinetics. A series of simulations, without perturbations from the outflow boundary to the detonation front, are carried out while the degree of overdrive, f, is varied between 1.10 and 1.74 (f=D2/DCJ2; where D is detonation velocity). Shock pressure histories and x-t diagrams are utilized in order to attain precise understanding of the one-dimensional unsteady detonations. At higher degrees of overdrive, f=1.40-1.74, shock pressure histories agree with those of previous studies. The oscillation mechanism is the same as that of the large-disturbance regime of unsteady shock-induced combustion around a projectile. At lower degrees of overdrive, f<1.30, grid resolution affects the eventual results, because half reaction time in the shock pressure exhibits considerable variation. Four typical kinds of oscillation pattern are discussed and are explained by their x-t diagrams and shock pressure histories. Each oscillation mechanism is essentially the same as that of the large-disturbance regime. The reignition process in the failed regime was numerically investigated at f=1.01-1.25. The reignition points tend to converge on a specified point in study of grid refinement, although the oscillation of the shock pressure histories becomes chaotic, suggesting the existence of a unique solution for reignition. All the simulation results for f=1.01-1.20 show the failed regime after initial disturbance at the early stage. The failed regime is compared with the solution of the Riemann problem, and analysis consisting of a Rayleigh line for weak leading shock and a partially burnt Hugoniot curve is adopted. Analysis suggests the concept of partial chemical heat release, indicating the possibility of discontinuous change in conditions, and, indeed, simulation indicates occurrence of explosion. The explosion time derived from the analysis agrees well with the results of simulation.

Daimon, Yu; Matsuo, Akiko

2003-01-01

107

From chromium-chromium quintuple bonds to molecular squares and porous coordination polymers.  

PubMed

Reaction of the quintuply bonded chromium(I) dimer [ApCrCrAp] (Ap = sterically demanding 2-aminopyridinate) with pyrazine yields a chromium(II) complex with a ?(4):?(4) face-on coordinated pyrazine dianion. Reaction with 4,4'-bipyridine, on the other hand, completely cleaves the metal-metal bond, leading to a chromium(II)-based molecular square. XRD and magnetic measurements show ligand radical anions and a ferrimagnetic alignment of alternating metal and ligand magnetic moments. Controlled polymerization of the molecular square with pyrazine yields a porous coordination polymer featuring both reduced and nonreduced linkers. PMID:25384210

Noor, Awal; Sobgwi Tamne, Emmanuel; Oelkers, Benjamin; Bauer, Tobias; Demeshko, Serhiy; Meyer, Franc; Heinemann, Frank W; Kempe, Rhett

2014-12-01

108

SUSY-inspired one-dimensional transformation optics  

E-print Network

Transformation optics aims to identify artificial materials and structures with desired electromagnetic properties by means of pertinent coordinate transformations. In general, such schemes are meant to appropriately tailor the constitutive parameters of metamaterials in order to control the trajectory of light in two and three dimensions. Here we introduce a new class of one-dimensional optical transformations that exploits the mathematical framework of supersymmetry (SUSY). This systematic approach can be utilized to synthesize photonic configurations with identical reflection and transmission characteristics, down to the phase, for all incident angles, thus rendering them perfectly indistinguishable to an external observer. Along these lines, low-contrast dielectric arrangements can be designed to fully mimic the behavior of a given high-contrast structure that would have been otherwise beyond the reach of available materials and existing fabrication techniques. Similar strategies can also be adopted to replace negative-permittivity domains, thus averting unwanted optical losses.

Mohammad-Ali Miri; Matthias Heinrich; Demetrios N. Christodoulides

2014-08-04

109

Postsynthesis modification of a porous coordination polymer by LiCl To enhance H+ transport.  

PubMed

A Ca(2+) porous coordination polymer with 1D channels was functionalized by the postsynthesis addition of LiCl to enhance the H(+) conductivity. The compound showed over 10(-2) S cm(-1) at 25 °C and 20% relative humidity. Pulse-field gradient NMR elucidated that the fast H(+) conductivity was achieved by the support of Li(+) ion movements in the channel. PMID:23485151

Horike, Satoshi; Kamitsubo, Yusuke; Inukai, Munehiro; Fukushima, Tomohiro; Umeyama, Daiki; Itakura, Tomoya; Kitagawa, Susumu

2013-03-27

110

Low-dimensional porous coordination polymers based on 1,2-bis(4-pyridyl)hydrazine: from structure diversity to ultrahigh CO2/CH4 selectivity.  

PubMed

Solvothermal reactions of metal salts, benzenedicarboxylic acids, and 4,4'-azopyridine (azpy) in different conditions produced four coordination polymers, namely, [Zn(3)(bdc)(3)(bphy)(3)]·2DMF·10H(2)O (3; H(2)bdc = 1,4-benzenedicarboxylic acid, bphy = 1,2-bis(4-pyridyl)hydrazine, and DMF = N,N-dimethylformamide), [Ni(bdc)(bphy)]·DMF·3.5H(2)O (4), [Zn(nipa)(bphy)]·EtOH (5; H(2)nipa = 5-nitroisophthalic acid), and [CoBr(bdc)(0.5)(bphy)]·2DMA·H(2)O (6; DMA = N,N-dimethylacetamide), in which the azpy ligand was in situ reduced. Structural determination reveals that 3-5 consist of the same metal/ligand ratio and similar coordination modes, as well as similar two-dimensional square-grid networks, but differ from their packing/interpenetration modes. 3 consists of alternately arranged single layers and interweaved double layers. Single layers in 4 directly stack in an offset fashion, while 5 is constructed of interdigitated double layers. 6 is a one-dimensional ladderlike structure, which could be regarded as that half of the bridging benzenedicarboxylate ligands in 3-5 are replaced by monodentate bromide ions. Interestingly, the crystal structures of these low-dimensional coordination polymers contain considerable solvent-accessible voids. Thermogravimetric curves, powder X-ray diffraction, and gas sorption experiments were used to study the potential porosity of these structures, which indicated that they can all reversibly desorb and adsorb solvent molecules. In particular, 4 showed gated sorption behavior and high CO(2)/CH(4) selectivity because of its flexible structure. PMID:22564113

Liu, Xiao-Min; Lin, Rui-Biao; Zhang, Jie-Peng; Chen, Xiao-Ming

2012-05-21

111

Micromolding of a Highly Fluorescent Reticular Coordination Polymer: Solvent-Mediated Reconfigurable Polymerization in a Soft Lithographic Mold  

SciTech Connect

Coordination polymerization of pyridine-based ligands and zinc or silver ions was controlled by soft lithographic micromolding in capillaries. The polymer patterns that are produced are highly fluorescent and supramolecularly structured.

Y You; H Yang; J Chung; J Kim; Y Jung; S Park

2011-12-31

112

Structural and luminescent properties of micro- and nanosized particles of lanthanide terephthalate coordination polymers.  

PubMed

Reaction in water between rare earth ions (Ln = Y, La-Tm, except Pm) and the sodium salt of terephthalic acid leads to a family of lanthanide-based coordination polymers of general formula [Ln2(C8H4O4)3(H2O)4] n with Ln = La-Tm or Y. The isostructurality of the compounds with the previously reported Tb-containing polymer is ascertained on the basis of their X-ray powder diffraction diagrams. The coordination water molecules can be reversibly removed without destroying the crystal structure for compounds involving one of the lighter lanthanide ions (La-Eu). For compounds involving one of the heavier lanthanide ions (Tb-Tm) or yttrium, a structural change occurs during the drying process. X-ray diffraction data show this new anhydrous phase corresponding to the linking of pairs of Er(III) ions through mu-carboxylate bridges. Porosity profiles calculated for the anhydrous phases of Tb(III) and Er(III) show the presence of channels with very small sections. The luminescent properties of all the compounds have been recorded and the two most luminescent polymers, namely, the europium- and the terbium-containing ones, have been studied in more detail. Tb(III)-containing compounds display large quantum yields, up to 43%. Polyvinylpyrrolidone nanoparticles doped with [Ln2(C8H4O4)3(H2O)4] n (Ln = Eu, Tb, Er) have also been synthesized and characterized. The encapsulation of the coordination polymers results in somewhat reduced luminescence intensities and lifetime, but the nanoparticles can be dispersed in water and remain unchanged in this medium for more than 20 h. PMID:18366158

Daiguebonne, Carole; Kerbellec, Nicolas; Guillou, Olivier; Bünzli, Jean-Claude; Gumy, Frederic; Catala, Laure; Mallah, Talal; Audebrand, Nathalie; Gérault, Yves; Bernot, Kevin; Calvez, Guillaume

2008-05-01

113

One 1D T4(0)A(0) water tape embedded in a 1D Cu(II) coordination polymer with 1,3-bis(4-pyridyl)propane  

NASA Astrophysics Data System (ADS)

The reaction of Cu(OH) 2 ( in situ synthesized from CuCl 2·2H 2O and NaOH), bpp and H 2ox gave rise to a novel Cu(II) coordination polymer under ultrasonic irradiation at ambient temperature, namely [Cu(bpp)(ox)(H 2O)·5H 2O] n ( 1) (bpp = 1,3-bis(4-pyridyl)propane, H 2ox = oxalic acid). In the complex 1, Cu(II) cations are bridged by bpp ligands to form a one-dimensional (1D) infinite wave-like polymeric chain. The coordinated ox 2- anions and water molecules interact with each other by six different hydrogen-bonding motifs and extend the 1D polymeric chain into a two-dimensional (2D) bilayer pattern. Of further interest, one 1D T4(0)A(0) water tape consisting of alternate cyclic water tetramers resides in the channel structure of 1.

Xiong, Hong-Bo; Sun, Di; Luo, Geng-Geng; Huang, Rong-Bin; Dai, Jing-Cao

2011-03-01

114

Selective Adsorption of CO2 from Light Gas Mixtures Using a Structurally Dynamic Porous Coordination Polymer**  

SciTech Connect

The selective adsorption of CO{sub 2} from mixtures with N{sub 2}, CH{sub 4}, and N{sub 2}O in a dynamic porous coordination polymer (see monomer structure) was evaluated by ATR-FTIR spectroscopy, GC, and SANS. All three techniques indicate highly selective adsorption of CO{sub 2} from CO{sub 2}/CH{sub 4} and CO{sub 2}/N{sub 2} mixtures at 30 C, with no selectivity observed for the CO{sub 2}/N{sub 2}O system.

Kristi L. Kauffman, Jeffrey T. Culp, Andrew J. Allen, Laura Espinal, Winnie Wong-Ng, Thomas D.

2010-01-01

115

Lattice architecture effect on the cooperativity of spin transition coordination polymers  

SciTech Connect

We have investigated in the framework of the Ising-like model, by means of Monte Carlo Metropolis method with open boundary condition, the architecture effect on the cooperativity of spin transition coordination polymers. We have analyzed the influence of several physical parameters (size, pressure, and edge effects) on different lattice architectures which were in good agreement with reported experimental data. We show that the cooperativity of a spin crossover system, characterized by the same number of molecules and the same short- and long-range interaction parameters, is progressively enhanced when going from a 1D chain to a 1D ladder type lattice and to a 2D square lattice.

Chiruta, Daniel [Faculty of Electrical Engineering and Computer Science and Advanced Materials and Nanotechnology Laboratory (AMNOL), ?tefan cel Mare University, Suceava 720229 (Romania); GEMaC, Université de Versailles Saint-Quentin-en-Yvelines, CNRS-UVSQ (UMR 8635), 78035 Versailles Cedex (France); LISV, Université de Versailles Saint-Quentin-en-Yvelines, 78140 Velizy (France); Jureschi, Catalin-Maricel; Rotaru, Aurelian, E-mail: jorge.linares@uvsq.fr, E-mail: rotaru@eed.usv.ro [Faculty of Electrical Engineering and Computer Science and Advanced Materials and Nanotechnology Laboratory (AMNOL), ?tefan cel Mare University, Suceava 720229 (Romania); Linares, Jorge, E-mail: jorge.linares@uvsq.fr, E-mail: rotaru@eed.usv.ro [GEMaC, Université de Versailles Saint-Quentin-en-Yvelines, CNRS-UVSQ (UMR 8635), 78035 Versailles Cedex (France); Garcia, Yann [Institute of Condensed Matter and Nanosciences, Molecules, Solids and Reactivity (IMCN/MOST), Université Catholique de Louvain, Place L. Pasteur, 1, 1348 Louvain-la-Neuve (Belgium)

2014-02-07

116

A new pillared-layer 3D coordination polymer involving in situ generated formate  

NASA Astrophysics Data System (ADS)

A new Cd-based coordination polymer, [Cd(cpt)(HCOO)]n (1), has been synthesized from 1-(4-carboxyphenyl)-1,2,4-triazole) ligand (Hcpt). The structure was characterized through X-ray crystallography, elemental analysis, and IR spectrum. Compound 1 presents a three-dimensional (3D) pillared-layer structure constructed by metal-formate layers and cpt- ligands. Moreover, the unusual formate anions are generated in situ from the decomposition of DMF precursors. The fluorescence property of 1 in solid state was also researched.

Xia, Yu-Pei; Li, Yun-Wu; Li, Da-Cheng; Du, Yu-Chang; Yao, Qing-Xia; Dou, Jian-Min

2015-02-01

117

A triple helical calcium-based coordination polymer with strong blue fluorescent emission  

NASA Astrophysics Data System (ADS)

A hydrothermal reaction of 1,3-dicyanobenzene and Ca(OH) 2 yielded a triple helical calcium-based coordination polymer of the formula, C 20H 25Ca 2.50O 18.50 ( 1). The 1,3-benzenecarboxylate anion, found in the final product was generated in situ during the synthesis by the hydrolysis of 1,3-dicyanobenzene. X-ray diffraction study shows that the complex 1 crystallizes in the monoclinic system, C2/c space group, a=15.5701(5), b=21.4445(7), c=17.1601(6) Å, ?=111.7400(7)°, V=5322.1(3) Å 3, Z=8, Dc=1.651 Mg/m 3. The calcium atoms show differences in the coordination environments. Complex 1 emits strong blue fluorescent light ( ?em(max)=419 nm) when it is excited by UV light ( ?ex(max)=316 nm) in the solid state at room temperature.

Yu, Liang-Cai; Chen, Zhen-Feng; Liang, Hong; Zhou, Chun-Shan; Li, Yan

2005-08-01

118

A new 3D silver(I) coordination polymer with croconate ligand displaying green luminescent  

NASA Astrophysics Data System (ADS)

One new polymer, [Ag4(C5O5)2(H2O)2]n (C5O52- = croconate dianion), has been synthesized and characterized by element analysis, IR, Raman, single-crystal X-ray diffraction, PXRD, and luminescent analysis. X-ray structural analysis revealed that the ligand was de-protonized entirely and offered five oxygen donors taking part in the coordination, and the tetranuclear silver(I) ions showed 4 and 5 coordination geometries respectively. From the space perspective, the presence of 1D chains that are connected into 2D layers, which are further connected into 3D network can be found within the crystal structure by Agsbnd O and weak Ag⋯Ag interactions. The thermal decomposition process consists of the loss of corresponding water molecules below 380 °C and follow-up decomposition of the main structure. Under the excitation of 380 nm light, the complex displayed green luminescent emission at room temperature.

Feng, Sisi; Yang, Hui; Jiang, Xiaojing; Wang, Yuxiang; Zhu, Miaoli

2015-02-01

119

Aromatic carboxylate effect on dimensionality of three bis(benzimidazole)-based cobalt(II) coordination polymers: Syntheses, structures and properties  

SciTech Connect

Three new metal-organic coordination polymers [Co(4-bbc){sub 2}(bbbm)] (1), [Co(3,5-pdc)(bbbm)]·2H{sub 2}O (2) and [Co(1,4-ndc)(bbbm)] (3) (4-Hbbc=4-bromobenzoic acid, 3,5-H{sub 2}pdc=3,5-pyridinedicarboxylic acid, 1,4-H{sub 2}ndc=1,4-naphthalenedicarboxylic acid and bbbm=1,1-(1,4-butanediyl)bis-1H-benzimidazole) were hydrothermally synthesized and structurally characterized. Polymer 1 is a 1D chain formed by the bbbm ligands and Co{sup II} ions. Polymer 2 exhibits a 2D network with a (3·4·5)(3{sup 2}·4·5·6{sup 2}·7{sup 4}) topology. Polymer 3 possesses a 3D three-fold interpenetrating framework. The versatile structures of title polymers indicate that the aromatic carboxylates have an important influence on the dimensionality of 1–3. Moreover, the thermal stability, electrochemical and luminescent properties of 1–3 were investigated. - graphical abstract: Three bis(benzimidazole)-based cobalt(II) coordination polymers tuned by aromatic carboxylates were hydrothermally synthesized and structurally characterized. The aromatic carboxylates play a key role in the dimensionality of three polymers. The electrochemical and luminescent properties of three polymers were investigated. Display Omitted - Highlights: • Three bis(benzimidazole)-based cobalt(II) coordination polymers tuned by aromatic carboxylates were obtained. • The aromatic carboxylates have an important influence on the dimensionality of three polymers. • The electrochemical and luminescent properties of three polymers were investigated.

Zhang, Ju-Wen; Gong, Chun-Hua; Hou, Li-Li; Tian, Ai-Xiang; Wang, Xiu-Li, E-mail: wangxiuli@bhu.edu.cn

2013-09-15

120

Coordinates  

NSDL National Science Digital Library

This introduction to the labeling of points on a plane by their Cartesian coordinates can optionally be extended to coordinates in 3-dimensional space, to plane polar coordinates and to 3-dimensional polar coordinates. Students should learn to use Cartesian coordinates (x,y) for defining the position of a point in two dimensions and to use Cartesian coordinates (x,y,z) in 3-dimensional space and learn to appreciate the two ways of defining the z axis. Students should also become familiar with some of the tools and terms used by surveyors such as theodolite, azimuth, elevation, and zenith. Optional items for students familiar with trigonometry and with the theorem of Pythagoras are polar coordinates (r,f ) on the plane, Converting (r,f) to (x,y) and vice versa, at least for r, and Spherical polar coordinates (r,q, f) in 3-dimensional space.

Stern, David

121

Spectroscopic properties of a series of Co(II) coordination polymers and the influence of Co(II) coordination environment on photoelectric property.  

PubMed

Four Co(II) coordination polymers, [Co(suc)]n1, [Co(pdc)]n2, {[Co7(suc)4(OH)6(H2O)3]·8H2O}n3, {[Co(bdc)(phen)(H2O)]·H2O}n4 (H2suc=succinic acid, H2pdc=pyridine-3,4-dicarboxylic acid, H2bdc=1,2-benzenedicarboxylic acid, phen=1,10-phenanthroline) were hydrothermally synthesized and characterized by X-ray single-crystal diffraction, surface photovoltage spectroscopy (SPS), electrical conductivity, thermogravimetric analysis (TG), ultraviolet visible and near-infrared absorption spectrum (UV-Vis-NIR), infrared spectrum (IR), and elemental analysis. The structural analyses indicate that the coordination numbers of the Co(II) ions are 4, 5, 6 and 6 for the polymers 1-4, respectively. And polymers 1 and 2 exhibit 3D structure formed by suc(2-) and pdc(2-) anions bridging Co(II) ions, respectively. Polymer 3 exhibits a 2D structure with suc(2-) anions bridging seven-nuclear [Co7(OH)6(H2O)3](3-) unit and polymer 4 is a 1D structure bridged by bdc(2-) anions. The surface photoelectric properties of the cobalt polymers were mainly studied by SPS. The results of SPS reveal that all polymers possess certain photoelectric conversion property in the range of 300-800nm. The influences of the structure, coordination micro-environment of central metal ion and structural dimensionality on response bands of SPS were discussed. PMID:25280332

Jin, Jing; Gong, Yuanyuan; Li, Lei; Han, Xiao; Meng, Qin; Liu, Yonghua; Niu, Shuyun

2015-02-25

122

Spectroscopic properties of a series of Co(II) coordination polymers and the influence of Co(II) coordination environment on photoelectric property  

NASA Astrophysics Data System (ADS)

Four Co(II) coordination polymers, [Co(suc)]n1, [Co(pdc)]n2, {[Co7(suc)4(OH)6(H2O)3] · 8H2O}n3, {[Co(bdc)(phen)(H2O)] · H2O}n4 (H2suc = succinic acid, H2pdc = pyridine-3,4-dicarboxylic acid, H2bdc = 1,2-benzenedicarboxylic acid, phen = 1,10-phenanthroline) were hydrothermally synthesized and characterized by X-ray single-crystal diffraction, surface photovoltage spectroscopy (SPS), electrical conductivity, thermogravimetric analysis (TG), ultraviolet visible and near-infrared absorption spectrum (UV-Vis-NIR), infrared spectrum (IR), and elemental analysis. The structural analyses indicate that the coordination numbers of the Co(II) ions are 4, 5, 6 and 6 for the polymers 1-4, respectively. And polymers 1 and 2 exhibit 3D structure formed by suc2- and pdc2- anions bridging Co(II) ions, respectively. Polymer 3 exhibits a 2D structure with suc2- anions bridging seven-nuclear [Co7(OH)6(H2O)3]3- unit and polymer 4 is a 1D structure bridged by bdc2- anions. The surface photoelectric properties of the cobalt polymers were mainly studied by SPS. The results of SPS reveal that all polymers possess certain photoelectric conversion property in the range of 300-800 nm. The influences of the structure, coordination micro-environment of central metal ion and structural dimensionality on response bands of SPS were discussed.

Jin, Jing; Gong, Yuanyuan; Li, Lei; Han, Xiao; Meng, Qin; Liu, Yonghua; Niu, Shuyun

2015-02-01

123

Controlled synthesis of porous coordination-polymer microcrystals with definite morphologies and sizes under mild conditions.  

PubMed

Herein, we report a facile and convenient method for the synthesis of the porous coordination polymer MOF-14 [Cu3 (BTB)2 ] (H3 BTB=4,4',4''-benzene-1,3,5-triyl-tribenzoic acid) as microcrystals with definite shapes and crystal facets controlled by the reaction medium at room temperature. The amount of sodium acetate added to the reaction system plays a crucial role in the shape evolution of MOF-14 from rhombic dodecahedrons to truncated rhombic dodecahedrons and cubes with truncated edges and then to cubes. The addition of a base could accelerate the formation rate of crystal growth and increase the supersaturation of crystal growth, thus resulting in the formation of MOF-14 cube crystals with high-energy crystal facets. The morphological evolution was also observed for HKUST-1 [Cu3 (BTC)2 ] (H3 BTC=1,3,5-benzenetricarbocylic acid) from octahedrons to cubes, thus verifying the probable mechanism of the morphological transformation. The gas-adsorption properties of MOF-14 with different shapes were studied and reveal that the porous coordination-polymer microcrystals display excellent and morphology-dependent sorption properties. PMID:25224902

Liu, Qing; Yang, Ji-Min; Jin, Li-Na; Sun, Wei-Yin

2014-11-01

124

Yttrium-succinates coordination polymers: Hydrothermal synthesis, crystal structure and thermal decomposition  

SciTech Connect

New polymeric yttrium-succinates, Y{sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}(H{sub 2}O){sub 4}.6H{sub 2}O and Y{sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}(H{sub 2}O){sub 2}, have been synthesized, and their structures (solved by single crystal XRD) are compared with that of Y{sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}(H{sub 2}O){sub 2}.H{sub 2}O. Three compounds were obtained as single phases, and their thermal behaviour is described. - Graphical abstract: In the field of coordination polymers or MOF's, few studies report on the polymorphs of Ln(III)-succinic acid. Here, we describe the hydrothermal synthesis and structural characterization of two novel yttrium-succinates coordination polymers, respectively 2D and 3D, Y{sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}(H{sub 2}O){sub 4}.6H{sub 2}O and Y{sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}(H{sub 2}O){sub 2}.

Amghouz, Zakariae; Roces, Laura; Garcia-Granda, Santiago [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo, 33006 Oviedo (Spain); Garcia, Jose R., E-mail: jrgm@uniovi.e [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo, 33006 Oviedo (Spain); Souhail, Badredine [Departement de Chimie, Faculte des Sciences, Universite Abdelmalek Essaadi, 93002 Tetouan, Maroc (Morocco); Mafra, Luis; Shi, Fa-nian; Rocha, Joao [Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal)

2009-12-15

125

Integration of intrinsic proton conduction and guest-accessible nanospace into a coordination polymer.  

PubMed

We report the synthesis and characterization of a coordination polymer that exhibits both intrinsic proton conductivity and gas adsorption. The coordination polymer, consisting of zinc ions, benzimidazole, and orthophosphate, exhibits a degree of flexibility in that it adopts different structures before and after dehydration. The dehydrated form shows higher intrinsic proton conductivity than the original form, reaching as high as 1.3 × 10(-3) S cm(-1) at 120 °C. We found that the rearranged conduction path and liquid-like behavior of benzimidazole molecules in the channel of the framework afforded the high proton conductivity. Of the two forms of the framework, only the dehydrated form is porous to methanol and demonstrates guest-accessible space in the structure. The proton conductivity of the dehydrated form increases by 24 times as a result of the in situ adsorption of methanol molecules, demonstrating the dual functionality of the framework. NMR studies revealed a hydrogen-bond interaction between the framework and methanol, which enables the modulation of proton conductivity within the framework. PMID:23829398

Umeyama, Daiki; Horike, Satoshi; Inukai, Munehiro; Kitagawa, Susumu

2013-07-31

126

Two unusual 12-connected metal–organic coordination polymers with fcu net  

SciTech Connect

Two new three-dimensional 12-connected metal–organic coordination polymers, [Zn{sub 2}(bptc)(H{sub 2}O)]·C{sub 2}H{sub 5}OH·H{sub 2}O (1) and [Cd{sub 4}(bptc){sub 2}(bbi)(H{sub 2}O)]·H{sub 2}O (2) (H4bptc=biphenyl-2,5,2?,5?-tetracarboxylic acid, bbi=1,1?-(1,4-butanediyl)bis(imidazole)), have been solvothermally synthesized and structurally characterized by single crystal X-ray diffraction analyses. All compounds are also characterized by elemental analyses, IR spectra, thermogravimetric (TG) analyses and X-ray powder diffraction (XRD). Topological analysis indicates that both 1 and 2 are 12-connected frameworks with fcu topology, which are based on cuboid cage and rob-like (Cd3) subunit as 12-connected nodes, respectively. Furthermore, the luminescence properties of the two compounds were discussed in detail. - Graphical abstract: Two new compounds with unusual 12-connected fcu topology display intriguing structural feature, as well as luminescence property. Display Omitted - Highlights: • Two new 3D metal–organic coordination polymers based on biphenyl-2,5,2?,5?-tetracarboxylic acid ligand have been synthesized. • Two compounds exhibit rare 12-connected fcu topology. • Photoluminescent property at room temperature has been investigated.

Guo, Sheng-Qi [Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China); Tian, Dan; Luo, Yu-Hui [Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Chen, Xin [School of Pharmaceutical and Life Sciences, Changzhou University, Changzhou, Jiangsu, 213164 (China); Zhang, Hong, E-mail: zhangh@nenu.edu.cn [Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

2013-09-15

127

Localized cell stimulation by nitric oxide using a photoactive porous coordination polymer platform  

PubMed Central

Functional cellular substrates for localized cell stimulation by small molecules provide an opportunity to control and monitor cell signalling networks chemically in time and space. However, despite improvements in the controlled delivery of bioactive compounds, the precise localization of gaseous biomolecules at the single-cell level remains challenging. Here we target nitric oxide, a crucial signalling molecule with site-specific and concentration-dependent activities, and we report a synthetic strategy for developing spatiotemporally controllable nitric oxide-releasing platforms based on photoactive porous coordination polymers. By organizing molecules with poor reactivity into polymer structures, we observe increased photoreactivity and adjustable release using light irradiation. We embed photoactive polymer crystals in a biocompatible matrix and achieve precisely controlled nitric oxide delivery at the cellular level via localized two-photon laser activation. The biological relevance of the exogenous nitric oxide produced by this strategy is evidenced by an intracellular change in calcium concentration, mediated by nitric oxide-responsive plasma membrane channel proteins. PMID:24158008

Diring, Stéphane; Wang, Dan Ohtan; Kim, Chiwon; Kondo, Mio; Chen, Yong; Kitagawa, Susumu; Kamei, Ken-ichiro; Furukawa, Shuhei

2013-01-01

128

MULTIPLICITY FREE SPACES WITH A ONE DIMENSIONAL HUBERT RUBENTHALER  

E-print Network

MULTIPLICITY FREE SPACES WITH A ONE DIMENSIONAL QUOTIENT HUBERT RUBENTHALER Abstract. The multiplicity free spaces with a one dimensional quotient were introduced by Thierry Levasseur in [11]. Recently. Introduction 1 2. Multiplicity free spaces. Basic definitions and properties 2 2.1. Prehomogeneous Vector

Paris-Sud XI, Université de

129

Stepwise Nanopore Evolution in One-Dimensional Nanostructures  

E-print Network

Stepwise Nanopore Evolution in One-Dimensional Nanostructures Jang Wook Choi,, James Mc be used to produce nanopores inside various useful one-dimensional (1D) nanostructures such as zinc oxide of the unique combination of nanoporosity and 1D materials and demonstrate nanoporous silicon nanowires (po

Cui, Yi

130

Conductance distribution in quasi-one-dimensional disordered quantum wires  

E-print Network

to insulator transition at zero temperature even in the absence of electron­electron interactions [6Conductance distribution in quasi-one-dimensional disordered quantum wires K.A. Muttalib,a P-one-dimensional wire within the model of non-interacting fermions. The method has been used in [Phys. Rev. Lett. 83

Muttalib, Khandker

131

Reversible chemisorption of sulfur dioxide in a spin crossover porous coordination polymer.  

PubMed

The chemisorption of sulfur dioxide (SO2) on the Hofmann-like spin crossover porous coordination polymer (SCO-PCP) {Fe(pz)[Pt(CN)4]} has been investigated at room temperature. Thermal analysis and adsorption-desorption isotherms showed that ca. 1 mol of SO2 per mol of {Fe(pz)[Pt(CN)4]} was retained in the pores. Nevertheless, the SO2 was loosely attached to the walls of the host network and completely released in 24 h at 298 K. Single crystals of {Fe(pz)[Pt(CN)4]}·nSO2 (n ? 0.25) were grown in water solutions saturated with SO2, and its crystal structure was analyzed at 120 K. The SO2 molecule is coordinated to the Pt(II) ion through the sulfur atom ion, Pt-S = 2.585(4) Å. This coordination slightly stabilizes the low-spin state of the Fe(II) ions shifting the critical temperatures of the spin transition by 8-12 K. DFT calculations have been performed to rationalize these observations. PMID:24124923

Arcís-Castillo, Zulema; Muñoz-Lara, Francisco J; Muñoz, M Carmen; Aravena, Daniel; Gaspar, Ana B; Sánchez-Royo, Juan F; Ruiz, Eliseo; Ohba, Masaaki; Matsuda, Ryotaro; Kitagawa, Susumu; Real, José A

2013-11-01

132

Self-assembly of silver(I) coordination polymers from aminopyrimidyl derivatives and malonate acid: From 1D chain to 2D layer  

NASA Astrophysics Data System (ADS)

Two new silver(I) coordination polymers (CPs) of the formula [Ag 2(dmapym) 4(mal)·H 2O] n ( 1) and [Ag 3(apym) 3(mal)NO 3] n ( 2) (dmapym = 2-amino-4,6-dimethylprimidine, apym = 2-aminopyrimidine, H 2mal = malonate) have been synthesized by reactions of AgNO 3 and 2-aminopyrimidyl ligands with malonate under the ammoniacal condition. Both complexes have been characterized by element analysis, IR and single-crystal X-ray diffraction. The monodentate dmapym and tridentate mal ligands link Ag(I) ions to give complex 1 a one-dimensional (1D) H-shaped chain structure. The complex 2 is a two-dimensional (2D) double sheet structure constructed by (4, 4) single sheet. Additionally, the hydrogen-bonding and C-H⋯? interactions also direct the self-assembly of supramolecular architectures. The photoluminescence properties of the 1 and 2 were investigated in the solid state at room temperature.

Sun, Di; Zhang, Na; Xu, Qin-Juan; Luo, Geng-Geng; Huang, Rong-Bin; Zheng, Lan-Sun

2010-04-01

133

A CuII coordination polymer based on incorporated carboxylate and sulfonate groups: Synthesis, crystal structure, and magnetic properties  

NASA Astrophysics Data System (ADS)

A CuII coordination polymer, [Cu(sbpc)(phen)(H2O)]?H2O 1, has been synthesized and characterized structurally and magnetically (H2sbpc = 4-sulfobiphenyl-4?-carboxylic acid, phen = 1,10-phenanthroline). Single-crystal structural analysis shows that 1 consists of dinuclear [Cu2(CO2)2] units bridged via sbpc2- to afford a 1-D chain, which then extends into the 3-D coordination polymer supramolecular network by O-H⋯O hydrogen bonds and ?⋯? interactions. Magnetic measurements indicate that complex 1 exhibits weak antiferromagnetic coupling.

Han, Yinfeng; Zheng, Zebao; Wang, Chang'an; Sun, Jiafeng; Li, Xiaoyan; Zhang, Jianping; Xiao, Jing; He, Guofang; Li, Liqing

2015-01-01

134

Hardening transition in a one-dimensional model for ferrogels.  

PubMed

We introduce and investigate a coarse-grained model for quasi one-dimensional ferrogels. In our description the magnetic particles are represented by hard spheres with a magnetic dipole moment in their centers. Harmonic springs connecting these spheres mimic the presence of a cross-linked polymer matrix. A special emphasis is put on the coupling of the dipolar orientations to the elastic deformations of the matrix, where a memory effect of the orientations is included. Although the particles are displaced along one spatial direction only, the system already shows rich behavior: as a function of the magnetic dipole moment, we find a phase transition between "soft-elastic" states with finite interparticle separation and finite compressive elastic modulus on the one hand, and "hardened" states with touching particles and therefore diverging compressive elastic modulus on the other hand. Corresponding phase diagrams are derived neglecting thermal fluctuations of the magnetic particles. In addition, we consider a situation in which a spatially homogeneous magnetization is initially imprinted into the material. Depending on the strength of the magneto-mechanical coupling between the dipole orientations and the elastic deformations, the system then relaxes to a uniaxially ferromagnetic, an antiferromagnetic, or a spiral state of magnetization to minimize its energy. One purpose of our work is to provide a largely analytically solvable approach that can provide a benchmark to test future descriptions of higher complexity. From an applied point of view, our results could be exploited, for example, for the construction of novel damping devices of tunable shock absorbance. PMID:23742515

Annunziata, Mario Alberto; Menzel, Andreas M; Löwen, Hartmut

2013-05-28

135

Hardening transition in a one-dimensional model for ferrogels  

NASA Astrophysics Data System (ADS)

We introduce and investigate a coarse-grained model for quasi one-dimensional ferrogels. In our description the magnetic particles are represented by hard spheres with a magnetic dipole moment in their centers. Harmonic springs connecting these spheres mimic the presence of a cross-linked polymer matrix. A special emphasis is put on the coupling of the dipolar orientations to the elastic deformations of the matrix, where a memory effect of the orientations is included. Although the particles are displaced along one spatial direction only, the system already shows rich behavior: as a function of the magnetic dipole moment, we find a phase transition between "soft-elastic" states with finite interparticle separation and finite compressive elastic modulus on the one hand, and "hardened" states with touching particles and therefore diverging compressive elastic modulus on the other hand. Corresponding phase diagrams are derived neglecting thermal fluctuations of the magnetic particles. In addition, we consider a situation in which a spatially homogeneous magnetization is initially imprinted into the material. Depending on the strength of the magneto-mechanical coupling between the dipole orientations and the elastic deformations, the system then relaxes to a uniaxially ferromagnetic, an antiferromagnetic, or a spiral state of magnetization to minimize its energy. One purpose of our work is to provide a largely analytically solvable approach that can provide a benchmark to test future descriptions of higher complexity. From an applied point of view, our results could be exploited, for example, for the construction of novel damping devices of tunable shock absorbance.

Annunziata, Mario Alberto; Menzel, Andreas M.; Löwen, Hartmut

2013-05-01

136

Isostructural 1D coordination polymers of Zn(II), Cd(II) and Cu(II) with phenylpropynoic acid and DABCO as organic linkers  

NASA Astrophysics Data System (ADS)

Using phenylpropynoic acid (PPA) and 1,4-diazabicyclo[2.2.2]octane (DABCO) as organic spacers, isostructural coordination polymers of Zn(II), Cd(II) and Cu(II) were synthesized by solvothermal method and structurally characterized using single crystal XRD, powder XRD, 13C CP-MAS NMR spectroscopy. Single crystal XRD data revealed four PPA units coordinating with two metal ions forming a paddle wheel secondary building unit (SBU). The paddle wheel units are connected through coordination of DABCO nitrogen to the metal centers from the axial positions leading to the formation of the 1D coordination polymers along the c axis. Intermolecular ? stacking and Csbnd H…? interactions between the adjacent polymer chains convert the 1D coordination polymer into an interesting 3D network with the Csbnd H…? bonds running along the crystallographic a and b axes. Thermal and nitrogen adsorption studies of these coordination polymers are reported.

Saravanakumar, Rajendran; Varghese, Babu; Sankararaman, Sethuraman

2014-11-01

137

Flexible Two-Dimensional Square-Grid Coordination Polymers: Structures and Functions  

PubMed Central

Coordination polymers (CPs) or metal-organic frameworks (MOFs) have attracted considerable attention because of the tunable diversity of structures and functions. A 4,4?-bipyridine molecule, which is a simple, linear, exobidentate, and rigid ligand molecule, can construct two-dimensional (2D) square grid type CPs. Only the 2D-CPs with appropriate metal cations and counter anions exhibit flexibility and adsorb gas with a gate mechanism and these 2D-CPs are called elastic layer-structured metal-organic frameworks (ELMs). Such a unique property can make it possible to overcome the dilemma of strong adsorption and easy desorption, which is one of the ideal properties for practical adsorbents. PMID:21152303

Kajiro, Hiroshi; Kondo, Atsushi; Kaneko, Katsumi; Kanoh, Hirofumi

2010-01-01

138

Linear alkaline earth metal phosphinate coordination polymers: synthesis and structural characterization.  

PubMed

Reaction of alkaline earth metal salts with diphenylphosphinic acid in dimethylformamide solvent afforded four coordination polymers: [Mg3(O2PPh2)6(DMF)2]·2DMF (I), [Ca(O2PPh2)2(DMF)2] (II), [Sr(O2PPh2)2(DMF)2] (III) and [Ba(O2PPh2)2(DMF)2] (IV) (where DMF is N,N-dimethylformamide). Single-crystal X-ray diffraction revealed that all four compounds produce linear chain structures in the solid state, with the Ca, Sr and Ba forming isostructural crystals. The bulk materials were characterized by FT-IR and (1)H NMR spectroscopy and elemental analyses. PMID:24892607

Rood, Jeffrey A; Huttenstine, Ashley L; Schmidt, Zachery A; White, Michael R; Oliver, Allen G

2014-06-01

139

Pressure-induced amorphization of a dense coordination polymer and its impact on proton conductivity  

NASA Astrophysics Data System (ADS)

The proton conductivity of a dense coordination polymer (CP) was investigated under high-pressure conditions. Impedance measurements under high pressures revealed that the proton conductivity of the CP decreased more than 1000-fold at pressures of 3-7 GPa and that the activation energy for proton conduction almost doubled compared with that at ambient pressure. A synchrotron X-ray study under high pressure identified the amorphization process of the CP during compression, which rationally explains the decrease in conductivity and increase in activation energy. This phenomenon is categorized as reversible pressure-induced amorphization of a dense CP and is regarded as a demonstration of the coupling of the mechanical and electrical properties of a CP.

Umeyama, Daiki; Horike, Satoshi; Tassel, Cedric; Kageyama, Hiroshi; Higo, Yuji; Hagi, Keisuke; Ogiwara, Naoki; Kitagawa, Susumu

2014-12-01

140

Catalytic glucose isomerization by porous coordination polymers with open metal sites.  

PubMed

Highly efficient catalytic isomerization reactions from glucose to fructose in aqueous media using porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) is reported for the first time. The catalytic activity of PCPs functionalized with -NH2, -(CH3)2, -NO2, and -SO3H groups on the pore surface is systematically tested. The catalytic activity can be tuned by the acidity of open metal sites (OMSs) by modifying the organic linkers with the functional groups. As a result, it is demonstrated that MIL-101 functionalized with -SO3H not only shows high conversion of glucose but also selectively produces fructose. Further, catalytic one-pot conversion of amylose to fructose is achieved, thanks to the high stability of the framework in an acidic solution. These results show that MOF/PCP compounds having OMSs are promising materials for various useful heterogeneous catalytic reactions, in particular in the biomass field. PMID:25080129

Akiyama, George; Matsuda, Ryotaro; Sato, Hiroshi; Kitagawa, Susumu

2014-10-01

141

A systematic study on the stability of porous coordination polymers against ammonia.  

PubMed

To establish a strategy for designing porous coordination polymers (PCPs) for ammonia capture, the first systematic study on the stability of PCPs against ammonia was conducted. Various types of PCPs were investigated by comparing their powder XRD patterns before and after treatment with ammonia. Among the PCPs tested, ZIF-8, MIL-53(Al), Al-BTB, MOF-76(M) (M=Y or Yb), MIL-101(Cr), and MOF-74(Mg) were stable up to 350?°C under an ammonia atmosphere at ambient pressure. The origin of the stability of PCPs is discussed from the viewpoint of their components, metal cations, and organic linkers. Furthermore, adsorption isotherm measurements show that the adsorptive behavior of PCPs is independent of their stability. PMID:25313521

Kajiwara, Takashi; Higuchi, Masakazu; Watanabe, Daisuke; Higashimura, Hideyuki; Yamada, Teppei; Kitagawa, Hiroshi

2014-11-17

142

Lipid-Coated Nanoscale Coordination Polymers for Targeted Delivery of Antifolates to Cancer Cells  

PubMed Central

Nanoscale coordination polymers (NCPs) have been demonstrated as an interesting platform for drug delivery, as they possess many advantages over small-molecule chemotherapeutics, such as high payloads, lower systemic toxicity, tunability, and enhanced tumor uptake. Existing formulations for the delivery of methotrexate (MTX), an antifolate cancer drug, have very low drug loadings. Herein, we report the incorporation of MTX as a building block in an NCP formulation with exceptionally high drug loadings (up to 79.1 wt%) and the selective delivery of the NCP to cancer cells. Encapsulation of the NCP in a functionalized lipid bilayer allows for targeted delivery and controlled release to cancer cells. A phosphor can be doped into the NCPs for monitoring particle uptake by optical imaging. The lipid-coated and anisamide-targeted NCPs have superior in vitro efficacy against acute lymphoblastic leukemia cells when compared to free drug. PMID:24288587

Huxford, Rachel C.; deKrafft, Kathryn E.; Boyle, William S.; Liu, Demin

2013-01-01

143

4-(4-Carboxyphenoxy)phthalate-based coordination polymers and their application in sensing nitrobenzene.  

PubMed

Under hydro(solvo)thermal conditions, two 4-(4-carboxyphenoxy)phthalate-based three-dimensional (3-D) coordination polymers: [Cd3(cpph)2(bpa)2(H2O)]·0.5H2O (cpph = 4-(4-carboxyphenoxy)phthalate, bpa = 1,2-bis(4-pyridyl)ethane) , and [H2(bpp)][Mn2(cpph)2(H2O)2] (bpp = 1,2-bis(4-piperidyl)propane) were isolated. In both compounds, the cpph molecules extend the metal ions into a 3-D network: a (4,6)-connected net for and a simple 6-connected net with a pcu topology for . The introduced bpa or bpp molecule stabilizes the 3-D metal-cpph architecture in the form of linker or guest molecule. The sensing ability of was investigated, revealing that it can be used as a fluorescence probe to sense nitrobenzene at ppm concentrations. PMID:25436936

Wang, Yan-Ning; Zhang, Ping; Yu, Jie-Hui; Xu, Ji-Qing

2014-12-23

144

Pressure-induced amorphization of a dense coordination polymer and its impact on proton conductivity  

SciTech Connect

The proton conductivity of a dense coordination polymer (CP) was investigated under high-pressure conditions. Impedance measurements under high pressures revealed that the proton conductivity of the CP decreased more than 1000-fold at pressures of 3–7 GPa and that the activation energy for proton conduction almost doubled compared with that at ambient pressure. A synchrotron X-ray study under high pressure identified the amorphization process of the CP during compression, which rationally explains the decrease in conductivity and increase in activation energy. This phenomenon is categorized as reversible pressure-induced amorphization of a dense CP and is regarded as a demonstration of the coupling of the mechanical and electrical properties of a CP.

Umeyama, Daiki; Hagi, Keisuke; Ogiwara, Naoki [Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Horike, Satoshi, E-mail: horike@sbchem.kyoto-u.ac.jp, E-mail: kitagawa@icems.kyoto-u.ac.jp [Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Tassel, Cedric [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); The Hakubi Center for Advanced Research, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501 (Japan); Kageyama, Hiroshi [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Higo, Yuji [Japan Synchrotron Radiation Research Institute, Hyogo 679-5198 (Japan); Kitagawa, Susumu, E-mail: horike@sbchem.kyoto-u.ac.jp, E-mail: kitagawa@icems.kyoto-u.ac.jp [Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501 (Japan)

2014-12-01

145

Synthesis, crystal structure and photoluminescent properties of four lanthanide 5-nitroisophthalate coordination polymers  

SciTech Connect

Four new lanthanide coordination polymers, [Y(Hnip)(nip)(H{sub 2}O)].H{sub 2}O (1), [Ln(Hnip)(nip)(H{sub 2}O){sub 2}].2H{sub 2}O [Ln=Eu(2), Tb(3)] and [Y(nip){sub 2}].(H{sub 2}4,4'-bpy){sub 0.5} (4) [5-nip=5-nitroisophthalate, 4,4'-bpy=4,4'-bipyridine], have been hydrothermally synthesized and structurally characterized. Compound 1 features novel lanthanide-carboxylate groups chains composed of three samehanded helical strands intersecting each other through hinged lanthanide atoms, and these chains are cross-linked by phenylene moieties of carboxylate ligands into a 2D layer structure. Compounds 2 and 3 are isomorphous, and contain 1D catenanelike Ln-O-C-O-Ln chains, which are interconnected by phenylene moieties into 2D layer structures. Compound 4, however, displays a 3D architecture sustained by strong hydrogen bonding interactions between the protonated 4,4'-bpy and the carboxyl oxygen atom from [Y{sub 2}(nip){sub 4}]{sup 2-} with 2D layer structure, and 4,4'-bpy as the guest molecules exist in bilayer channel. The studies for the thermal stabilities of the four compounds show that compound 4 is more stable than other compounds. Compound 2 emits characteristic red luminescence of Eu{sup 3+} ions at room temperature, and its luminescent lifetime and quantum efficiency has been determined. - Graphical abstract: Four lanthanide 5-nitroisophthalate coordination polymers have been hydrothermally prepared and resent different structures and thermal stabilities and photoluminescence properties.

Huang Yan [Department of Chemistry, Tongji University, Shanghai 200092 (China); Yan Bing, E-mail: byan@tongji.edu.c [Department of Chemistry, Tongji University, Shanghai 200092 (China); State Key Lab of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Shao Min [Department of Chemistry, College of Science, Shanghai University, Shanghai 200444 (China)

2009-04-15

146

Anion-controlled assembly of silver-di(aminophenyl)sulfone coordination polymers: Syntheses, crystal structures, and solid state luminescence  

SciTech Connect

Five silver coordination polymers, namely, ([Ag(3,3?-daps){sub 2}]·BF{sub 4}){sub n} (1), ([Ag(3,3?-daps){sub 2}]·NO{sub 3}){sub n} (2), [Ag(3,3?-daps)(CF{sub 3}SO{sub 3})]{sub n} (3), ([Ag(4,4?-daps)]·CF{sub 3}SO{sub 3}){sub n} (4), and ([Ag(4,4?-daps)]·ClO{sub 4}){sub n} (5) (3,3?-daps=di(3?-aminodiphenyl)sulfone, and 4,4?-daps=di(4?-aminodiphenyl)sulfone) have been synthesized and structural characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction analyses. Complex 1 displays a 1D ladder-like chain with four-connected Ag ions and bridged 3,3?-daps. Complex 2 shows other 1D ladder chain modified by tentacles. Complex 3 is a 2D layer structure with both Ag ions and 3,3?-daps are 3-connected nodes. Complex 4 is another 1D ladder chain with three-connected Ag ions and 4,4?-daps. Complex 5 shows a 2D 4{sup 4}-sql net with Ag ions and 4,4?-daps as 4-connected nodes. Moreover, their solid state luminescence and thermal stabilities also have been investigated. - Graphical abstract: Pictogram: Synthetic procedures of the five anion controlled silver coordination polymers. We reported the synthetic procedures, structure, and luminescence property of the five anion controlled silver coordination polymers based on two novel di(aminophenyl)sulfone V-shaped ligands. Display Omitted - Highlights: • Five new silver coordination polymers were synthesized and characterized. • Two novel designed V-shaped di(aminophenyl)sulfone ligands were first introduced to coordination chemistry. • Anions play important roles in determining the five silver coordination polymers. • The structural diversity and photoluminescence property were also discussed.

Zhang, Qi-Long, E-mail: gzuqlzhang@126.com [Department of Chemistry, Guiyang Medical College, Guiyang 550004 (China); Hu, Peng [Department of Chemistry, Guiyang Medical College, Guiyang 550004 (China); Zhao, Yi [Key Laboratory of Macrocyclic and Supramolecular Chemistry, Guizhou University, Guiyang 550025 (China); Feng, Guang-Wei [Department of Chemistry, Guiyang Medical College, Guiyang 550004 (China); Zhang, Yun-Qian; Zhu, Bi-Xue; Tao, Zhu [Key Laboratory of Macrocyclic and Supramolecular Chemistry, Guizhou University, Guiyang 550025 (China)

2014-02-15

147

Structure and magnetic properties of heterometallic coordination carboxylate polymers with cobalt and lithium atoms  

SciTech Connect

Reactions between lithium pivalate and cobalt coordination polymers [Co{sub 5}(OH{sub 2})(OH)(Piv){sub 9})L{sup 1}){sub 4}]{sub n} (I) and [Co{sub 2}(OH{sub 2})(Piv){sub 4}(L{sup 2}){sub 2}]{sub n} (II), where Piv-is the pivalate anion, L{sup 1} is pyrazine, and L{sup 2} is pyrimidine, result in new heterometallic polymers {l_brace}[Li{sub 2}Co{sub 2}(Piv){sub 6}(L{sup 1}){sub 2}]{sub 2}MeCN{r_brace}{sub n} (III), {l_brace}[Li{sub 2}Co{sub 2}(Piv){sub 6}(L{sup 2})]{sub 0.5}MeCN{r_brace}{sub n} (IV), and [Li{sub 2}Co{sub 2}(Piv){sub 6}(L{sup 2}){sub 2}]{sub n} (V). The resulting compounds contain tetra-nuclear {l_brace}Li{sub 2}Co{sub 2}(Piv){sub 6}{r_brace} fragments connected by neutral bridging ligands (pyrazine or pyrimidine) into layer structures. Crystal structures III-V are determined, and the magnetic properties of III and IV are studied.

Evstifeev, I. E.; Kiskin, M. A., E-mail: mkiskin@igic.ras.ru [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation); Bogomyakov, A. S. [Russian Academy of Sciences, International Tomography Center, Siberian Branch (Russian Federation); Sidorov, A. A.; Novotortsev, V. M.; Eremenko, I. L. [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation)

2011-09-15

148

Mechanism of ultrasound scission of a silver-carbene coordination polymer.  

PubMed

Scission of a supramolecular polymer-metal complex can be carried out using collapsing cavitation bubbles created by ultrasound. Although the most plausible scission mechanism of the coordinative bonds is through mechanical force, the influence of radicals and high hot-spot temperatures on scission has to be considered. A silver(I)-N-heterocyclic carbene complex was exposed to 20 kHz ultrasound in argon, nitrogen, methane, and isobutane saturated toluene. Scission percentages were almost equal under argon, nitrogen, and methane. Radical production differs by a factor of 10 under these gases, indicating that radical production is not a significant contributor to the scission process. A model to describe the displacement of the bubble wall, strain rates, and temperature in the gas shows that critical strain rates for coil-to-stretch transition, needed for scission, are achieved at reactor temperatures of 298 K, an acoustic pressure of 1.2 × 10(5) Pa, and an acoustic frequency of 20 kHz. Lower scission percentages were measured under isobutane, which also shows lower strain rates in model simulations. The activation of the polymer-metal complexes in toluene under the influence of ultrasound occurs through mechanical force. PMID:21827184

Rooze, Joost; Groote, Ramon; Jakobs, Robert T M; Sijbesma, Rint P; van Iersel, Maikel M; Rebrov, Evgeny V; Schouten, Jaap C; Keurentjes, Jos T F

2011-09-29

149

Four homochiral coordination polymers contain N-acetyl-L-tyrosine and different N-donor ligand: Influence of metal cations, ancillary ligands and coordination modes  

SciTech Connect

Using the chiral ligand N-acetyl-L-tyrosine (Hacty) and maintaining identical reaction conditions, Zn(II), Co(II), and Cd(II) salts provided four novel homochiral coordination polymers ([Zn(acty)(bipy){sub 2}(H{sub 2}O){sub 2}]·NO{sub 3}·2H{sub 2}O){sub n}1, ([Co(acty)(bipy){sub 2}(H{sub 2}O){sub 2}]·NO{sub 3}·2H{sub 2}O){sub n}2, ([Cd(acty){sub 2}(bipy)H{sub 2}O]·H{sub 2}O){sub n}3, and ([Cd(acty)(bpe){sub 2}(Ac)]·6H{sub 2}O){sub n}4 (bipy=4,4?-bipyridine; bpe=1,2-di(4-pyridyl)ethane) in the presence of ancillary ligands. Compounds 1 and 2 are isostructural 1D chain structures. The neighboring chains are further linked into a 3D supramolecular structure via ??? stacking and hydrogen bond interactions. Compound 3 shows a 2D network and 4 generates 1D infinite chains along the c-axis. Compounds 3 and 4 are further connected into 3D supramolecular network by hydrogen bond interactions. More importantly, coordination in acyl oxygen atoms and ancillary ligands (bpe) as monodentate decorating ligands in 4 are rarely reported. Ancillary ligands and metal cations significantly influence the structure of the complexes. The photoluminescence properties of 1, 3, and 4 were studied at room temperature. Circular dichroism (CD) of the complexes have been investigated. - Graphical abstract: Four new homochiral coordination polymers were prepared and structurally characterized, which investigate the influence of the ancillary ligands and metal ions on the design and synthesis of coordination polymers. Display Omitted - Highlights: • It is rarely reported that the chiral coordination polymers prepared with N-acetyl-L-tyrosine ligands. • The alkalescent acetyl oxygen atom is difficult to participate in coordination but it is happened in the N-acetyl-L-tyrosine ligands. • The ancillary ligands (4,4?-bipy and bpe) are present in an unusual coordination modes, monodentate decorating ligands in 1, 2 and 4. • Structure comparative analyses results indicate that the secondary ligands and metal ions influence the fabrication of these inorganic–organic arrangements.

Li, Meng-Li; Song, Hui-Hua, E-mail: flower9486@163.com

2013-10-15

150

Synthesis And Characterization Of One-Dimensional Oxide Nanostructures.  

E-print Network

??Nanostructured materials especially, one-dimensional (1D) nanostructures have unique physical, chemical, mechanical properties and are the building blocks for a range of nanoscale devices. The procedure… (more)

Vanithakumari, S C

2009-01-01

151

Ripening of one-dimensional molecular nanostructures on  

E-print Network

Ripening of one-dimensional molecular nanostructures on insulating surfaces Master Thesis Tobias Naturwissenschaften TU Ilmenau July 8, 2011 #12;Contents 1 Introduction 4 2 Nucleation, growth and ripening 6 2 epitaxy . . . . . . . . . . . . . . . . . . . . 7 2.3 Ripening

Steinhoff, Heinz-Jürgen

152

Computation of the one-dimensional unwrapped phase  

E-print Network

In this thesis, the computation of the unwrapped phase of the discrete-time Fourier transform (DTFT) of a one-dimensional finite-length signal is explored. The phase of the DTFT is not unique, and may contain integer ...

Karam, Zahi Nadim

2006-01-01

153

A linear heterometallic bismuth-copper coordination polymer containing two types of organic ligands.  

PubMed

In the linear coordination polymer catena-poly[[[aqua(1,10-phenanthroline-?(2)N,N')copper(II)]-?-pyridine-2,6-dicarboxylato-?(4)O(2):O(2'),N,O(6)-[(nitrato-?(2)O,O')bismuth(III)]-?-pyridine-2,6-dicarboxylato-?(4)O(2),N,O(6):O(6')] dihydrate], {[Bi(III)Cu(II)(C7H3NO4)2(NO3)(C12H8N2)(H2O)]·2H2O}n, the Bi(III) cation is O,N,O'-chelated by the two pyridine-2,6-dicarboxylate ligands and O,O'-chelated by the nitrate anion, the nine coordinating atoms conferring a tricapped trigonal prismatic environment on the metal centre. Each pyridine-2,6-dicarboxylate ligand uses one of its carboxylate O atoms to bind to an aqua(1,10-phenanthroline)copper(II) unit, the Cu-O dative bonds giving rise to the formation of a ribbon motif. The Cu(II) cation exhibits a square-pyramidal geometry. The ribbon motif propagates along the shortest axis of the triclinic unit cell and the solvent water molecules are hydrogen bonded to the same ribbon. PMID:25652275

Yue, Zi Long; Feng, Yu Quan; Ng, Seik Weng

2015-02-01

154

Exact solution of the one-dimensional Hubbard model with arbitrary boundary magnetic fields  

NASA Astrophysics Data System (ADS)

The one-dimensional Hubbard model with arbitrary boundary magnetic fields is solved exactly via the Bethe ansatz methods. With the coordinate Bethe ansatz in the charge sector, the second eigenvalue problem associated with the spin sector is constructed. It is shown that the second eigenvalue problem can be transformed into that of the inhomogeneous XXX spin chain with arbitrary boundary fields which can be solved via the off-diagonal Bethe ansatz method.

Li, Yuan-Yuan; Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

2014-02-01

155

Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are microporous crystalline materials composed by metal ions  

E-print Network

Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are microporous crystalline as linkers. Fig. 1 shows the schematics of such materials. MOFs are able to undergo reversible structural, suitable for applications such as adsorption-based separations, molecular storage, catalysis, and in situ

156

Directed Assembly of One-Dimensional Nanostructures into Functional Networks  

Microsoft Academic Search

One-dimensional nanostructures, such as nanowires and nanotubes, represent the smallest dimension for efficient transport of electrons and excitons and thus are ideal building blocks for hierarchical assembly of functional nanoscale electronic and photonic structures. We report an approach for the hierarchical assembly of one-dimensional nanostructures into well-defined functional networks. We show that nanowires can be assembled into parallel arrays with

Yu Huang; Xiangfeng Duan; Qingqiao Wei; Charles M. Lieber

2001-01-01

157

Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers  

SciTech Connect

The organic ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P2{sub 1}/c monoclinic system as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric analysis. Two new coordination networks based on lanthanide ions were obtained with this ligand using hydrothermal reaction. In addition to single-crystal X-ray diffraction, the compounds were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis. Single-crystal XRD showed that the compounds are isostructural, crystallizing in P2{sub 1}/n monoclinic system with chemical formula [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+}(1) and Eu{sup 3+}(2)).The luminescence properties of both compounds were studied. In the compound (1), a broad emission band was observed at 479 nm, redshifted by 70 nm in comparison of the free ligand. In (2), the typical f–f transition was observed with a maximum peak at 618 nm, related with the red emission of the europium ions. Computational methods were performed to simulate the crystal structure of (2). The theoretical calculations of the intensity parameters are in good agreement with the experimental values. - Graphical abstract: Scheme of obtaining the ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) and two new isostructural 3D-coordination polymers [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+} and Eu{sup 3+}) by hydrothermal synthesis. Display Omitted - Highlights: • The ligand 2,5-piperazinedione-1,4-diacetic acid was synthetized using the hydrothermic method and characterized. • Two new 3D-coordination polymers with this ligand containing Gd{sup 3+} and Eu{sup 3+} ions were also obtained. • The compounds are isostructural and the typical luminescent properties were observed in both structures.

Silva, Fausthon Fred da; Fernandes de Oliveira, Carlos Alberto; Lago Falcão, Eduardo Henrique [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil); Gatto, Claudia Cristina [Laboratório de Síntese Inorgânica e Cristalografia, Instituto de Química, Universidade de Brasília (IQ-UnB), 70904-970 Brasilia, DF (Brazil); Bezerra da Costa, Nivan; Oliveira Freire, Ricardo [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Chojnacki, Jaros?aw [Department of Inorganic Chemistry, Gdansk University of Technology, 80-233 Gdansk (Poland); Alves Júnior, Severino, E-mail: salvesjr@ufpe.br [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil)

2013-11-15

158

1D coordination polymers with polychalcogenides as linkers between metal atoms  

NASA Astrophysics Data System (ADS)

The reactions of zinc metal with elemental selenium and selenium/sulfur mixtures in liquid ammonia or methylamine under solvothermal conditions in closed glass ampoules at 50 °C lead within some days specifically to [Zn(NH3)2Se4]n (1), [Zn(MeNH2)2Se4]n (2), [Zn(NH3)2Se2.23S1.77]n (3). From MnCl2, Rb2Se and excess Se in n-butylamine [Mn(nBuNH2)4Se6]n (4) is obtained after prolonged reaction time at ambient temperature. The compounds are sensitive towards air and loss of NH3 or the amine ligands. The crystal structures were determined by single crystal diffraction at low temperatures. As a common structural feature, all compounds represent 1D coordination polymers with polychalcogenide chains as linkers between the metal atoms and consist of infinite [M-Chm-]n chains (M=Zn, Mn; Chm=Se4, (S/Se)4, Se6). The Zn central atoms in 1-3 have tetrahedral coordination with two amine ligands, the Mn atoms in 4 have octahedral coordination with four amine ligands and cis position of the two Se atoms. Raman spectra of 1-3 show the stretching mode vibrations of the Ch4 groups. The observation of S-S, S-Se, and Se-Se vibration bands in the spectrum of 3 indicates the presence of mixed S/Se polyanions. An optical band gap of 1.86(5) eV was determined for 2 by diffuse reflectance spectroscopy.

Kysliak, Oleksandr; Beck, Johannes

2013-07-01

159

A soft copper(II) porous coordination polymer with unprecedented aqua bridge and selective adsorption properties.  

PubMed

Herein, the synthesis, crystal structure, and full characterization of a new soft porous coordination polymer (PCP) of ([Cu(2)(dmcapz)(2)(OH(2))]DMF(1.5))(n) (1) formulation, which is easily obtained in the reaction of CuX(2) (X = Cl, NO(3)) salts with 3,5-dimethyl-4-carboxypyrazole (H(2)dmcapz) is present. Compound 1 shows a copper(II) dinuclear secondary building unit (SBU), which is supported by two pyrazolate bridges and an unprecedented H(2)O bridge. The dinuclear SBUs are further bridged by the carboxylate ligands to build a diamondoid porous network. The structural transformations taking place in 1 framework upon guest removal/uptake has been studied in detail. Indeed, the removal of the bridging water molecules gives rise to a metastable evacuated phase (1?b) that transforms into an extremely stable porous material (1?c) after freezing at liquid-nitrogen temperature. The soaking of 1?c into water allows the complete and instantaneous recover of the water-exchanged material (1?a'). Remarkably, 1?b and 1?c materials possess structural bistability, which results in the switchable adsorptive functions. Therefore, the gas-adsorption properties of both materials have been studied by means of single-component gas adsorption isotherms as well as by variable-temperature pulse-gas chromatography. Both materials present permanent porosity and selective gas-adsorption properties towards a variety of gases and vapors of environmental and industrial interest. Moreover, the flexible nature of the coordination network and the presence of highly active convergent open metal sites confer on these materials intriguing gas-adsorption properties with guest-triggered framework-breathing phenomena being observed. The plasticity of Cu(II) metal center and its ability to form stable complexes with different coordination numbers is at the origin of the structural transformations and the selective-adsorption properties of the studied materials. PMID:22933314

Quartapelle Procopio, Elsa; Fukushima, Tomohiro; Barea, Elisa; Navarro, Jorge A R; Horike, Satoshi; Kitagawa, Susumu

2012-10-01

160

Diffusion-coupled molecular assembly: structuring of coordination polymers across multiple length scales.  

PubMed

Porous coordination polymers (PCPs) are an intriguing class of molecular-based materials because of the designability of framework scaffolds, pore sizes and pore surface functionalities. Besides the structural designability at the molecular scale, the structuring of PCPs into mesoscopic/macroscopic morphologies has attracted much attention due to the significance for the practical applications. The structuring of PCPs at the mesoscopic/macroscopic scale has been so far demonstrated by the spatial localization of coordination reactions on the surface of templates or at the phase boundaries. However, these methodologies have never been applied to the fabrication of solid-solution or multivariate metal-organic frameworks (MOFs), in which multiple components are homogeneously mixed. Herein, we demonstrate the structuring of a box-type superstructure comprising of a solid-solution PCP by integrating a bidirectional diffusion of multiple organic ligands into molecular assembly. The parent crystals of [Zn2(ndc)2(bpy)]n were placed in the DMF solution of additional organic component of H2bdc, and the temperature was rapidly elevated up to 80 °C (ndc = 1,4-naphthalenedicarboxylate, bpy = 4,4'-bipyridyl, bdc = 1,4-benzenedicarboxylate). The dissolution of the parent crystals induced the outward diffusion of components; contrariwise, the accumulation of the other organic ligand of H2bdc induced the inward diffusion toward the surface of the parent crystals. This bidirectional diffusion of multiple components spatially localized the recrystallization at the surface of cuboid parent crystals; therefore, the nanocrystals of a solid-solution PCP ([Zn2(bdc)1.5(ndc)0.5(bpy)]n) were organized into a mesoscopic box superstructure. Furthermore, we demonstrated that the box superstructures enhanced the mass transfer kinetics for the separation of hydrocarbons. PMID:25254320

Hirai, Kenji; Reboul, Julien; Morone, Nobuhiro; Heuser, John E; Furukawa, Shuhei; Kitagawa, Susumu

2014-10-22

161

One dimensional speckle fields generated by three phase level diffusers  

NASA Astrophysics Data System (ADS)

Speckle patterns have usually been obtained by using ground glass as random diffusers. Liquid-crystal spatial light modulators have opened the possibility of engineering tailored speckle fields obtained from designed diffusers. In this work, one-dimensional Gaussian speckle fields with fully controllable features are generated. By employing a low-cost liquid-crystal spatial light modulator, one-dimensional three phase level diffusers are implemented. These diffusers make it possible to control average intensity distribution and statistical independence among the generated patterns. The average speckle size is governed by an external slit pupil. A theoretical model to describe the generated speckle patterns is developed. Experimental and theoretical results confirming the generation of one-dimensional speckle fields are presented. Some possible applications of these speckles, such as atom trapping and super-resolution imaging, are briefly envisaged.

Cabezas, L.; Amaya, D.; Bolognini, N.; Lencina, A.

2015-02-01

162

Interference of parametrically driven one-dimensional ultracold gases  

SciTech Connect

We theoretically analyze interference patterns of parametrically driven one-dimensional ultracold atomic gases. By modulating the interaction strength periodically in time, we propose to excite collective modes in a pair of independent one-dimensional gases at energies corresponding to the drive frequency. The excited collective modes lead to spatial oscillations in the correlations of the interference pattern, which can be analyzed to obtain the sound velocity of the collective modes. We discuss both bosonic and fermionic systems and how such experiments could be used to probe spin-charge separation.

Pielawa, Susanne [Physics Department, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-01-15

163

Hydrothermal Synthesis, Crystal Structure and Electrochemical Behavior of 2d Hybrid Coordination Polymer  

NASA Astrophysics Data System (ADS)

A novel metal-organic coordination polymer [Cu(phen)(L)0.5(H2O)]n (H4L = (N,N?-5,5?-bis(isophthalic acid)-p-xylylenediamine, and phen = 1,10-phenanthroline) has been hydrothermally synthesized and characterized by elemental analysis, IR, TGA, and single-crystal X-ray diffraction. The crystallographic data show that the title compound crystallizes in monoclinic space group P21/n with a = 10.682(2), b = 15.682(3), c = 11.909(2) Å, ? = 91.39(3)°, V = 1994.3(7) Å3, C24H17CuN3O5, Mr = 490.95, Dc = 1.635 g/cm3, F(000) = 1004, Z = 4, ?(MoK?) = 1.141 mm-1, the final R = 0.0418 and wR = 0.0983 for 3578 observed reflections (I > 2?(I)). The structural analyses reveal that the title compound exhibits shows a 2D layer structure, which are further linked by hydrogen bonding interactions to form a three-dimensional supramolecular network. In addition, the thermal stability and electrochemical behavior of title compound has been studied. CCDC: 900413.

Fan, Weiqiang; Zhu, Lin; Shi, Weidong; Chen, Fuxiao; Bai, Hongye; Song, Shuyan; Yan, Yongsheng

2013-06-01

164

Porous coordination polymers as novel sorption materials for heat transformation processes.  

PubMed

Porous coordination polymers (PCPs)/metal-organic frameworks (MOFs) are inorganic-organic hybrid materials with a permanent three-dimensional porous metal-ligand network. PCPs or MOFs are inorganic-organic analogs of zeolites in terms of porosity and reversible guest exchange properties. Microporous water-stable PCPs with high water uptake capacity are gaining attention for low temperature heat transformation applications in thermally driven adsorption chillers (TDCs) or adsorption heat pumps (AHPs). TDCs or AHPs are an alternative to traditional air conditioners or heat pumps operating on electricity or fossil fuels. By using solar or waste heat as the operating energy TDCs or AHPs can significantly help to minimize primary energy consumption and greenhouse gas emissions generated by industrial or domestic heating and cooling processes. TDCs and AHPs are based on the evaporation and consecutive adsorption of coolant liquids, preferably water, under specific conditions. The process is driven and controlled by the microporosity and hydrophilicity of the employed sorption material. Here we summarize the current investigations, developments and possibilities of PCPs/MOFs for use in low-temperature heat transformation applications as alternative materials for the traditional inorganic porous substances like silica gel, aluminophosphates or zeolites. PMID:23945102

Janiak, Christoph; Henninger, Stefan K

2013-01-01

165

Spectroscopic properties and the catalytic activity of new organo-lead supramolecular coordination polymer containing quinoxaline  

NASA Astrophysics Data System (ADS)

The 3D-supramolecular coordination polymer (SCP) 3?[ Cu2(CN)3(Me3Pb)(qox)], 1, as the first example of the CuCN SCP containing the (Me3Pb) fragment, was explored to investigate its catalytic and photo-catalytic activities. The structure of 1 contains two chemically identical but crystallographically different [Cu2(CN)3?Me3Pb?qox]2 units with four Cu(I) sites assuming distorted TP-3 geometry. Two non-linear chains of equal abundance are formed producing corrugated parallel chains which are connected laterally by quinoxaline creating 2D-layers which are arranged parallel in an (AB⋯AB⋯AB)n fashion forming 3D-network. IR, mass, electronic absorption and fluorescence spectra are also investigated. The SCP 1 is diamagnetic and exhibits good catalytic and photo-catalytic activities for the degradation of methylene blue (MB). The reaction is first order with respect to MB dye. The irradiation of the reaction with UV-light enhanced the rate of MB mineralization. The efficiency of recycled the 1 and the mechanism of degradation of MB dye were investigated.

Etaiw, Safaa El-din H.; Abdou, Safaa N.

2015-01-01

166

Self-assembled nanoscale coordination polymers with trigger release properties for effective anticancer therapy  

PubMed Central

Nanoscale coordination polymers (NCPs) are self-assembled from metal ions and organic bridging ligands, and can overcome many drawbacks of existing drug delivery systems by virtue of tunable compositions, sizes, and shapes; high drug loadings; ease of surface modification; and intrinsic biodegradability. Here we report the self-assembly of zinc bisphosphonate NCPs that carry 48±3 wt% cisplatin prodrug and 45±5 wt% oxaliplatin prodrug. In vivo pharmacokinetic studies in mice show minimal uptake of pegylated NCPs by the mononuclear phagocyte system and excellent blood circulation half-lives of 16.4±2.9 and 12.0±3.9 h for the NCPs carrying cisplatin and oxaliplatin, respectively. In all tumor xenograft models evaluated, including CT26 colon cancer, H460 lung cancer, and AsPC-1 pancreatic cancer, pegylated NCPs show superior potency and efficacy compared to free drugs. As the first example of using NCPs as nanotherapeutics with enhanced antitumor activities, this study establishes NCPs as a promising drug delivery platform for cancer therapy. PMID:24964370

Liu, Demin; Poon, Christopher; Lu, Kuangda; He, Chunbai; Lin, Wenbin

2014-01-01

167

Different dimensional coordination polymers with 4,4'-oxybis(benzoate): Syntheses, structures and properties  

NASA Astrophysics Data System (ADS)

Five transition-metal coordination polymers, namely, [Zn7Cl6(oba)4]n (1), [Cd7Cl6(oba)4]n (2), [Zn(oba)(H2O)]n (3), [Ag2(oba)]n (4) and [Co(oba)(H2O)2]n (5) (H2oba=4,4?-oxydibenzoic acid), have been achieved under hydrothermal conditions and structurally characterized by IR, elemental analyses, X-ray single-crystal diffraction and TGA. The X-ray single-crystal diffraction reveals that compounds 1 and 2 are isomorphism, featuring pillared-layer 3D motifs, in which the 2D inorganic layers (Zn6Cl7)n (or (Cd6Cl7)n) are connected by oba2- pillars. Compound 3 exhibits 1D stair-like chain and extends to a 3D network by two different interchain O-H-O hydrogen bonding interactions while compound 4 features wave chains and stretches to 2D layer by interchain Ag-O weak contacts. Compound 5 shows 2D network in which Co-chains are pillared by oba2- ligand and then forms a 3D network by four different O-H-O hydrogen bonding interactions. Furthermore, 1-4 exhibit luminescent properties at a solid state and 5 shows antiferromagnetic behavior.

Lun, Huijie; Li, Yamin; Zhang, Xudong; Yang, Jing-He; Xiao, Changyu; Xu, Yanqing; Li, Junrui

2014-07-01

168

Self-assembled nanoscale coordination polymers with trigger release properties for effective anticancer therapy  

NASA Astrophysics Data System (ADS)

Nanoscale coordination polymers (NCPs) are self-assembled from metal ions and organic bridging ligands, and can overcome many drawbacks of existing drug delivery systems by virtue of tunable compositions, sizes and shapes, high drug loadings, ease of surface modification and intrinsic biodegradability. Here we report the self-assembly of zinc bisphosphonate NCPs that carry 48±3?wt% cisplatin prodrug and 45±5?wt% oxaliplatin prodrug. In vivo pharmacokinetic studies in mice show minimal uptake of pegylated NCPs by the mononuclear phagocyte system and excellent blood circulation half-lives of 16.4±2.9 and 12.0±3.9?h for the NCPs carrying cisplatin and oxaliplatin, respectively. In all tumour xenograft models evaluated, including CT26 colon cancer, H460 lung cancer and AsPC-1 pancreatic cancer, pegylated NCPs show superior potency and efficacy compared with free drugs. As the first example of using NCPs as nanotherapeutics with enhanced antitumour activities, this study establishes NCPs as a promising drug delivery platform for cancer therapy.

Liu, Demin; Poon, Christopher; Lu, Kuangda; He, Chunbai; Lin, Wenbin

2014-06-01

169

Porous coordination polymers with ubiquitous and biocompatible metals and a neutral bridging ligand.  

PubMed

The design of inexpensive and less toxic porous coordination polymers (PCPs) that show selective adsorption or high adsorption capacity is a critical issue in research on applicable porous materials. Although use of Group II magnesium(II) and calcium(II) ions as building blocks could provide cheaper materials and lead to enhanced biocompatibility, examples of magnesium(II) and calcium(II) PCPs are extremely limited compared with commonly used transition metal ones, because neutral bridging ligands have not been available for magnesium(II) and calcium(II) ions. Here we report a rationally designed neutral and charge-polarized bridging ligand as a new partner for magnesium(II) and calcium(II) ions. The three-dimensional magnesium(II) and calcium(II) PCPs synthesized using such a neutral ligand are stable and show selective adsorption and separation of carbon dioxide over methane at ambient temperature. This synthetic approach allows the structural diversification of Group II magnesium(II) and calcium(II) PCPs. PMID:25592677

Noro, Shin-Ichiro; Mizutani, Junya; Hijikata, Yuh; Matsuda, Ryotaro; Sato, Hiroshi; Kitagawa, Susumu; Sugimoto, Kunihisa; Inubushi, Yasutaka; Kubo, Kazuya; Nakamura, Takayoshi

2015-01-01

170

Porous coordination polymers with ubiquitous and biocompatible metals and a neutral bridging ligand  

NASA Astrophysics Data System (ADS)

The design of inexpensive and less toxic porous coordination polymers (PCPs) that show selective adsorption or high adsorption capacity is a critical issue in research on applicable porous materials. Although use of Group II magnesium(II) and calcium(II) ions as building blocks could provide cheaper materials and lead to enhanced biocompatibility, examples of magnesium(II) and calcium(II) PCPs are extremely limited compared with commonly used transition metal ones, because neutral bridging ligands have not been available for magnesium(II) and calcium(II) ions. Here we report a rationally designed neutral and charge-polarized bridging ligand as a new partner for magnesium(II) and calcium(II) ions. The three-dimensional magnesium(II) and calcium(II) PCPs synthesized using such a neutral ligand are stable and show selective adsorption and separation of carbon dioxide over methane at ambient temperature. This synthetic approach allows the structural diversification of Group II magnesium(II) and calcium(II) PCPs.

Noro, Shin-Ichiro; Mizutani, Junya; Hijikata, Yuh; Matsuda, Ryotaro; Sato, Hiroshi; Kitagawa, Susumu; Sugimoto, Kunihisa; Inubushi, Yasutaka; Kubo, Kazuya; Nakamura, Takayoshi

2015-01-01

171

Carboxylic acid-doped SBA-15 silica as a host for metallo-supramolecular coordination polymers.  

PubMed

The adsorption of a metallo-supramolecular coordination polymer (Fe-MEPE) in the cylindrical pores of SBA-15 silica with pure and carboxylic acid (CA) carrying pore walls has been studied. Fe-MEPE is an intrinsically stiff polycation formed by complexation of Fe(II)-acetate with an uncharged ditopic bis-terpyridine ligand. The adsorption affinity and kinetics of the Fe-MEPE chains is strongly enhanced when the pore walls are doped with CA, and when the pH of the aqueous medium or temperature is increased. The initial fast uptake is connected with a decrease of pH of the aqueous solution, indicating an ion-exchange mechanism. It is followed by a slower (presumably diffusion-controlled) further uptake. The maximum adsorbed amount of Fe-MEPE in the CA-doped material corresponds to a monolayer of Fe-MEPE chains disposed side-by-side along the pore walls. The stoichiometry of Fe-MEPE in the pores (determined by XPS) was found to be independent of the loading and similar to that of the starting material. The mean chain length of Fe-MEPE before and after embedding in the CA-doped matrix was studied by solid-state 15N NMR using partially 15N-labeled Fe-MEPE. It is shown that the average chain length of Fe-MEPE is reduced when the complex is incorporated in the pores. PMID:18839983

Akcakayiran, D; Mauder, D; Hess, C; Sievers, T K; Kurth, D G; Shenderovich, I; Limbach, H-H; Findenegg, G H

2008-11-20

172

Porous coordination polymers with ubiquitous and biocompatible metals and a neutral bridging ligand  

PubMed Central

The design of inexpensive and less toxic porous coordination polymers (PCPs) that show selective adsorption or high adsorption capacity is a critical issue in research on applicable porous materials. Although use of Group II magnesium(II) and calcium(II) ions as building blocks could provide cheaper materials and lead to enhanced biocompatibility, examples of magnesium(II) and calcium(II) PCPs are extremely limited compared with commonly used transition metal ones, because neutral bridging ligands have not been available for magnesium(II) and calcium(II) ions. Here we report a rationally designed neutral and charge-polarized bridging ligand as a new partner for magnesium(II) and calcium(II) ions. The three-dimensional magnesium(II) and calcium(II) PCPs synthesized using such a neutral ligand are stable and show selective adsorption and separation of carbon dioxide over methane at ambient temperature. This synthetic approach allows the structural diversification of Group II magnesium(II) and calcium(II) PCPs. PMID:25592677

Noro, Shin-ichiro; Mizutani, Junya; Hijikata, Yuh; Matsuda, Ryotaro; Sato, Hiroshi; Kitagawa, Susumu; Sugimoto, Kunihisa; Inubushi, Yasutaka; Kubo, Kazuya; Nakamura, Takayoshi

2015-01-01

173

Terahertz phase contrast imaging of sorption kinetics in porous coordination polymer nanocrystals using differential optical resonator.  

PubMed

The enhancement of light-matter coupling when light is confined to wavelength scale volumes is useful both for studying small sample volumes and increasing the overall sensing ability. At these length scales, nonradiative interactions are of key interest to which near-field optical techniques may reveal new phenomena facilitating next-generation material functionalities and applications. Efforts to develop novel chemical or biological sensors using metamaterials have yielded innovative ideas in the optical and terahertz frequency range whereby the spatially integrated response over a resonator structure is monitored via the re-radiated or leaked light. But although terahertz waves generally exhibit distinctive response in chemical molecules or biological tissue, there is little absorption for subwavelength size sample and therefore poor image contrast. Here, we introduce a method that spatially resolves the differential near-field phase response of the entire resonator as a spectral fingerprint. By simultaneously probing two metallic ring resonators, where one loaded with the sample of interest, the differential phase response is able to resolve the presence of guest molecules (e.g. methanol) as they are adsorbed or released within the pores of a prototypical porous coordination polymer. PMID:24921804

Blanchard, F; Sumida, K; Wolpert, C; Tsotsalas, M; Tanaka, T; Doi, A; Kitagawa, S; Cooke, D G; Furukawa, S; Tanaka, K

2014-05-01

174

Structural assemblies of four Cd(II) coordination polymers based on 5-methylisophthalic acid  

NASA Astrophysics Data System (ADS)

Four new metal-organic coordination polymers, Cd(mip)(DMF)(1), Cd(mip)(EtOH)(2), Cd2(mip)2(H2O)5·3H2O (3), Cd(mip)(bpp)(H2O)·H2O (4) (H2mip = 5-methylisophthalic acid, bpp = 1,3-di(4-pyridyl)propane) have been hydro(solvo)thermally synthesized and characterized by IR, thermogravimetric (TG) analysis, powder X-ray diffraction and single-crystal X-ray diffraction. 1 and 2 are isostructural, and two adjacent Cd centers are bridged by four carboxylate groups in ?2-carboxylato-?1O.:?1O' and ?2?; ?2O,O' fashion to form a linear (Cd-O-Cd)n chain. The adjacent (Cd-O-Cd)n chains are further connected by mip bridges to form a 3D framework. 3 features two types of chiral layers: One left-handed and another right-handed, which lead to racemic solid-state compound. 4 exhibits a two-dimensional wave-like (2D) (4,4) layer structure with infinite 1D linear chain. In addition, the luminescent properties of 1-4 are also discussed.

Ji, Jian-Wei; Wang, Xiao-Fang; Li, Bi-Ye; Han, Zheng-Bo

2012-03-01

175

Switchable Guest Molecular Dynamics in a Perovskite-Like Coordination Polymer toward Sensitive Thermoresponsive Dielectric Materials.  

PubMed

A new perovskite-like coordination polymer [(CH3 )2 NH2 ][Cd(N3 )3 ] is reported which undergoes a reversible ferroelastic phase transition. This transition is due to varied modes of motion of the [(CH3 )2 NH2 ](+) guest accompanied by a synergistic deformation of the [Cd(N3 )3 ](-) framework. The unusual two-staged switchable dielectric relaxation reveals the molecular dynamics of the polar cation guest, which are well controlled by the variable confined space of the host framework. As the material switches from the ferroelastic phase to the paraelastic phase, a remarkable increase of the rotational energy barrier is detected. As a result, upon heating at low temperature, this compound shows a notable change from a low to a high dielectric state in the ferroelastic phase. This thermoresponsive host-guest system may serve as a model compound for the development of sensitive thermoresponsive dielectric materials and may be key to understanding and modulating molecular/ionic dynamics of guest molecules in confined space. PMID:25430633

Du, Zi-Yi; Xu, Ting-Ting; Huang, Bo; Su, Yu-Jun; Xue, Wei; He, Chun-Ting; Zhang, Wei-Xiong; Chen, Xiao-Ming

2014-11-27

176

A novel 1-D coordination Cu(II) polymer with alternating ? 1,3-squarato and binucleating polypyridylamine bridges  

Microsoft Academic Search

A novel 1-D coordination polymer {[Cu2(L)(?-1,3-C4O4)(ClO4)2]·1.33 H2O}n (C4O42-=3,4-dihydroxycyclobut-3-en-1,2-dionate, L=1,3-bis[bis(2-pyridylmethyl)aminomethyl]benzene was synthesized and structurally characterized by X-ray crystallography. The spectral and structural characterization, electrochemical and magnetic properties as well as thermo gravimetric analyses are reported. The structure of the complex consists of the ligand L bound to two Cu(II) centers and a bridging squarato in the 1,3-bonding mode. The coordination geometry

Thibaut LeGuet; Franz A. Mautner; Serhiy Demeshko; Franc Meyer; Richard S. Perkins; Salah S. Massoud

2009-01-01

177

Highly effective heterogeneous chemosensors of luminescent silica@coordination polymer core-shell micro-structures for metal ion sensing  

NASA Astrophysics Data System (ADS)

Heterogeneous solid sensors are regarded as promising next-generation sensor due to their excellent chemical stability, low contamination, and excellent recyclability, despite their low sensitivity and weak signal. The dispersity and signals specifically from the exterior of solid sensors are critical aspects which define the sensing sensitivity and selectivity. A novel strategy for the preparation of ideal heterogeneous sensors based upon luminescent lanthanide coordination polymers (LnCP) has been demonstrated. Ideal heterogeneous sensors are systematically achieved by producing the sensors in small, uniform, and thin core-shell particles (silica@LnCP, Ln = Eu, Tb). Eventually, we found that the extremely small amount of well-structured silica@LnCP microsphere, less than ca. 1/400 compared to the amount of several known coordination polymer-based sensors, was sufficient to achieve a reliable Cu2+ sensing with even much greater sensitivity (ca. 550% improvement).

Cho, Won; Lee, Hee Jung; Choi, Sora; Kim, Yoona; Oh, Moonhyun

2014-10-01

178

Highly effective heterogeneous chemosensors of luminescent silica@coordination polymer core-shell micro-structures for metal ion sensing  

PubMed Central

Heterogeneous solid sensors are regarded as promising next-generation sensor due to their excellent chemical stability, low contamination, and excellent recyclability, despite their low sensitivity and weak signal. The dispersity and signals specifically from the exterior of solid sensors are critical aspects which define the sensing sensitivity and selectivity. A novel strategy for the preparation of ideal heterogeneous sensors based upon luminescent lanthanide coordination polymers (LnCP) has been demonstrated. Ideal heterogeneous sensors are systematically achieved by producing the sensors in small, uniform, and thin core-shell particles (silica@LnCP, Ln = Eu, Tb). Eventually, we found that the extremely small amount of well-structured silica@LnCP microsphere, less than ca. 1/400 compared to the amount of several known coordination polymer-based sensors, was sufficient to achieve a reliable Cu2+ sensing with even much greater sensitivity (ca. 550% improvement). PMID:25269855

Cho, Won; Lee, Hee Jung; Choi, Sora; Kim, Yoona; Oh, Moonhyun

2014-01-01

179

Highly effective heterogeneous chemosensors of luminescent silica@coordination polymer core-shell micro-structures for metal ion sensing.  

PubMed

Heterogeneous solid sensors are regarded as promising next-generation sensor due to their excellent chemical stability, low contamination, and excellent recyclability, despite their low sensitivity and weak signal. The dispersity and signals specifically from the exterior of solid sensors are critical aspects which define the sensing sensitivity and selectivity. A novel strategy for the preparation of ideal heterogeneous sensors based upon luminescent lanthanide coordination polymers (LnCP) has been demonstrated. Ideal heterogeneous sensors are systematically achieved by producing the sensors in small, uniform, and thin core-shell particles (silica@LnCP, Ln = Eu, Tb). Eventually, we found that the extremely small amount of well-structured silica@LnCP microsphere, less than ca. 1/400 compared to the amount of several known coordination polymer-based sensors, was sufficient to achieve a reliable Cu(2+) sensing with even much greater sensitivity (ca. 550% improvement). PMID:25269855

Cho, Won; Lee, Hee Jung; Choi, Sora; Kim, Yoona; Oh, Moonhyun

2014-01-01

180

Enforced One-Dimensional Photoconductivity in Core-Cladding  

E-print Network

previously reported.1 We deposit thin films on quartz substrates by spin-casting4 and subsequently annealingEnforced One-Dimensional Photoconductivity in Core-Cladding Hexabenzocoronenes Yaron S. Cohen ABSTRACT Photoconductivity in contorted hexabenzocoronene liquid crystals is found to be exclusively one

Hone, James

181

Approximate Approaches to the One-Dimensional Finite Potential Well  

ERIC Educational Resources Information Center

The one-dimensional finite well is a textbook problem. We propose approximate approaches to obtain the energy levels of the well. The finite well is also encountered in semiconductor heterostructures where the carrier mass inside the well (m[subscript i]) is taken to be distinct from mass outside (m[subscript o]). A relevant parameter is the mass…

Singh, Shilpi; Pathak, Praveen; Singh, Vijay A.

2011-01-01

182

Thermal and Electrical Transport Study of One Dimensional Nanomaterials  

E-print Network

contribution due to scattering at the wire boundaries. Three one-dimensional nanostructured thermoelectric candidates - SiGe nanowires, SrTiO3 nanowires, and ZnO nanowires – were presented and discussed in this dissertation. SiGe nanowires are successfully...

Yin, Liang

2013-07-13

183

Transition density of one-dimensional diffusion with discontinuous drift  

NASA Technical Reports Server (NTRS)

The transition density of a one-dimensional diffusion process with a discontinuous drift coefficient is studied. A probabilistic representation of the transition density is given, illustrating the close connections between discontinuities of the drift and Brownian local times. In addition, some explicit results are obtained based on the trivariate density of Brownian motion, its occupation, and local times.

Zhang, Weijian

1990-01-01

184

One-Dimensional NOE Experiments Using Pulsed Field Gradients  

Microsoft Academic Search

Previously, it has been shown that the use of pulsed field gradients in one-dimensional NOE experiments results in spectra of much higher quality than it has previously been possible to record. Such high-quality spectra make it possible to measure, with complete confidence, very small NOE enhancements and also make it straightforward to measure NOE buildup curves. In this paper, the

Katherine Stott; James Keeler; Que N. Van; A. J. Shaka

1997-01-01

185

One-dimensional quantum scattering by a parabolic odd potential  

E-print Network

Quantum scattering by a one-dimensional odd potential proportional to the square of the distance to the origin is considered. The Schr\\"odinger equation is solved exactly and explicit algebraic expressions of the wavefunction are given. A complete discussion of the scattering function reveals the existence of Gamow (decaying) states and of resonances.

Erasmo M. Ferreira; Javier Sesma

2014-01-24

186

Teaching Module for One-Dimensional, Transient Conduction.  

ERIC Educational Resources Information Center

Describes a PC-based teaching module designed to instruct engineering students in transient one-dimensional conduction heat transfer analysis. The discussion considers problem formulation, nondimensionalization, discretization, numerical stability and the time-step restriction, program operation, and program verification. (MES)

Ribando, Robert J.; O'Leary, Gerald W.

1998-01-01

187

GLOBAL OPTIMIZATION FOR ONE-DIMENSIONAL STRUCTURE AND MOTION PROBLEMS  

E-print Network

inexpensive and reliable navigational systems for autonomous vehicles, see Figure 1.1. Strips of reflec- tor of autonomous vehicles, this is normally done when the system is installed to create a map which can.1. An autonomous guided vehicle that uses one-dimensional vision to navigate. High accuracy is needed, since the

Lunds Universitet

188

Molecular Cell Dynamic Basis for One-Dimensional DNA Scanning  

E-print Network

Molecular Cell Article Dynamic Basis for One-Dimensional DNA Scanning by the Mismatch Repair: Center For Comparative Functional Genomics, Department of Biology, New York University, 1009 Silver how these pro- teins might function we used single-molecule optical microscopy to answer the following

Chowdhury, Arindam

189

Analysis of spectral operators in one-dimensional domains  

NASA Technical Reports Server (NTRS)

Results are proven concerning certain projection operators on the space of all polynomials of degree less than or equal to N with respect to a class of one-dimensional weighted Sobolev spaces. The results are useful in the theory of the approximation of partial differential equations with spectral methods.

Maday, Y.

1985-01-01

190

Statistical mechanics of a one-dimensional lattice gas  

Microsoft Academic Search

We study the statistical mechanics of an infinite one-dimensional classical lattice gas. Extending a result ofvan Hove we show that, for a large class of interactions, such a system has no phase transition. The equilibrium state of the system is represented by a measure which is invariant under the effect of lattice translations. The dynamical system defined by this invariant

D. Ruelle

1968-01-01

191

Tensegrity Frameworks in the One-Dimensional Space Andrs RECSKI  

E-print Network

Tensegrity Frameworks in the One-Dimensional Space András RECSKI and Oer SHAI October 31, 2007 1 Abstract The edge set of a graph G is partitioned into two subsets EC ES. A tensegrity framework the rigidity of a given 1-dimensional embedding. 2 Introduction Tensegrity structures are pin

Shai, Offer

192

One-Dimensional Synthesis of Graphs as Tensegrity Andrs RECSKI  

E-print Network

One-Dimensional Synthesis of Graphs as Tensegrity Frameworks András RECSKI and Offer SHAI February 15, 2005 1 Abstract The edge set of a graph G is partitioned into two subsets EC ES. A tensegrity the rigidity of a given 1-dimensional embedding. 2 Introduction Tensegrity structures are pin

Shai, Offer

193

ACOUSTIC WAVE TRAPPING IN ONE-DIMENSIONAL AXISYMMETRIC ARRAYS  

E-print Network

ACOUSTIC WAVE TRAPPING IN ONE- DIMENSIONAL AXISYMMETRIC ARRAYS by M. MCIVER (Department 2011. Revise 2011] Summary The existence of acoustic, Rayleigh-Bloch modes in the vicinity of a one for the acoustic wave-field in the neighbourhood of such an array is obtained and solved with the use of a Galerkin

194

Faddeev equations in one-dimensional problems with resonant interactions  

NASA Astrophysics Data System (ADS)

A problem of three one-dimensional bosons with resonant multichannel interactions is considered. The problem is reduced to a single-channel Faddeev-Lovelace equation by elimination of the closed and output channels. The equation is regularized using algebraic properties of their singularities.

Yurovsky, V. A.

2009-08-01

195

Supercritical CO 2 -driven, periodic patterning on one-dimensionals carbon nanomaterials  

Microsoft Academic Search

One-dimensional carbon nano-materials, in particular carbon nanotubes (CNTs) and carbon nanofibers (CNFs), are of scientific\\u000a and technological interest due to their satisfactory properties and ability to serve as templates for directed assembly. In\\u000a this work, linear high density polyethylene (PE) was periodically decorated on CNTs and CNFs using a supercritical carbon\\u000a dioxide (scCO2)antisolvent-induced polymer epitaxy (SAIPE) method, leading to nano-hybrid

XiaoLi Zheng; Qun Xu; ZongPeng Li

2010-01-01

196

Optical, microscopic and low temperature electrical property of one-dimensional gold-polyaniline composite networks  

NASA Astrophysics Data System (ADS)

An in situ one pot synthesis route is described for the preparation of a gold-polyaniline nanocomposite material by polymerization of aniline hydrochloride using HAuCl4 as the oxidant. The resultant composite material was characterized by various techniques. The temperature-dependent electrical conductivity values were supportive of a thorough dispersion of metallic conducting centres and the interpretation is commensurate with the one-dimensional geometry of the composite material. The temperature dependence of the Hall coefficient of the gold-polymer composite is evidence of a possible contribution of a charge carrier deficit and a temperature-dependent mobility in this material.

Mallick, Kaushik; Witcomb, Mike; Scurrell, Mike; Strydom, André

2009-05-01

197

Square helix versus zigzag chain of group 12 metal coordination polymers with 1,2-bis(diphenylphosphino)ethane (dppe)  

Microsoft Academic Search

A novel 1D square-helical coordination polymer [ZnI2(?2-dppe)]n (1) was synthesized by the reaction of ZnI2 with 1,2-bis(diphenylphosphino)ethane (dppe), while zigzag chains [MX2(?2-dppe)]n were obtained by using smaller anions (Cl? and Br?) and larger metal ions (Cd2+ and Hg2+).

Xiaoqing Liu; Yanyan Liu; Yongjing Hao; Xiao-Juan Yang; Biao Wu

2010-01-01

198

Post-assembly guest oxidation in a metallo-supramolecular host and structural rearrangement to a coordination polymer.  

PubMed

PTA hosted in a copper metallo-supramolecular triangle undergoes post-assembly oxidation to form PTAO in aerated solutions. The oxidation is triggered by selected co-solvents that also govern the formation of the final crystalline product leading to a discrete host-guest triangle {PTAO@[Cu(o-L)]3} or to a 1D coordination polymer {(PTAO)2@[Cu8][Cu2]}? containing a {Cu8} ring with a double hosting pocket. PMID:25250982

Rancan, Marzio; Tessarolo, Jacopo; Quici, Silvio; Armelao, Lidia

2014-11-18

199

Structure Determination of the One-Dimensional Compound Sr3ZnPtO6, Containing Zinc in a  

E-print Network

Structure Determination of the One-Dimensional Compound Sr3ZnPtO6, Containing Zinc in a HighlyVember 9, 1995 We report the synthesis and structure of a new zinc-containing strontium platinum oxide, Sr3ZnPtO6, in which zinc is present in a highly unusual trigonal prismatic coordination environment

zur Loye, Hans-Conrad

200

The use of contact transformations of the inhomogeneous Monge-Ampere equation in one-dimensional gas dynamics  

Microsoft Academic Search

An approach to solving equations of one-dimensional gas dynamics is proposed which provides an alternative to the use of Euler and Lagrange coordinates. The approach uses Martin's substitution, which leads to the inhomogeneous Monger-Ampere equation. In this case, there are equations of state for which the contact symmetries of the equation form an infinite pseudogroup. The approach makes it possible

S. V. Khabirov

1990-01-01

201

Series of mixed uranyl-lanthanide (Ce, Nd) organic coordination polymers with aromatic polycarboxylates linkers.  

PubMed

Three series of mixed uranyl-lanthanide (Ce or Nd) carboxylate coordination polymers have been successfully synthesized by means of a hydrothermal route using either conventional or microwave heating methods. These compounds have been prepared from mixtures of uranyl nitrate, lanthanide nitrate together with phthalic acid (1,2), pyromellitic acid (3,4), or mellitic acid (5,6) in aqueous solution. The X-ray diffraction (XRD) single-crystal revealed that the phthalate complex (UO(2))(4)O(2)Ln(H(2)O)(7)(1,2-bdc)(4)·NH(4)·xH(2)O (Ln = Ce(1), Nd(2); x = 1 for 1, x = 0 for 2), is based on the connection of tetranuclear uranyl-centered building blocks linked to discrete monomeric units LnO(2)(H(2)O)(7) via the organic species to generate infinite chains, intercalated by free ammonium cations. The pyromellitate phase (UO(2))(3)Ln(2)(H(2)O)(12)(btec)(3)·5H(2)O (Ce(3), Nd(4)) contains layers of monomeric uranyl-centered hexagonal and pentagonal bipyramids linked via the carboxylate arms of the organic molecules. The three-dimensionality of the structure is ensured by the connection of remaining free carboxylate groups with isolated monomeric units LnO(2)(H(2)O)(7). The network of the third series (UO(2))(2)(OH)Ln(H(2)O)(7)(mel)·5H(2)O (Ce(5), Nd(6)) is built up from dinuclear uranyl units forming layers through connection with the mellitate ligands, which are further linked to each other through discrete monomers LnO(3)(H(2)O)(6). The thermal decomposition of the various coordination complexes led to the formation of mixed uranium-lanthanide oxide, with the fluorite-type structure at 1500 °C (for 1, 2) or 1400 °C for 3-6. Expected U/Ln ratio from the crystal structures were observed for compounds 1-6. PMID:22931214

Mihalcea, Ionut; Volkringer, Christophe; Henry, Natacha; Loiseau, Thierry

2012-09-17

202

Synthesis of nanostructured materials by using metal-cyanide coordination polymers and their lithium storage properties  

NASA Astrophysics Data System (ADS)

Herein, we demonstrate a novel and simple two-step process for preparing LiCoO2 nanocrystals by using a Prussian blue analogue Co3[Co(CN)6]2 as a precursor. The resultant LiCoO2 nanoparticles possess single crystalline nature and good uniformity with an average size of ca. 360 nm. The unique nanostructure of LiCoO2 provides relatively shorter Li+ diffusion pathways, thus facilitating the fast kinetics of electrochemical reactions. As a consequence, high reversible capacity, excellent cycling stability and rate capability are achieved with these nanocrystals as cathodes for lithium storage. The LiCoO2 nanocrystals deliver specific capacities of 154.5, 135.8, 119, and 100.3 mA h g-1 at 0.2, 0.4, 1, and 2 C rates, respectively. Even at a high current density of 4 C, a reversible capacity of 87 mA h g-1 could be maintained. Importantly, a capacity retention of 83.4% after 100 cycles is achieved at a constant discharge rate of 1 C. Furthermore, owing to facile control of the morphology and size of Prussian blue analogues by varying process parameters, as well as the tailored design of multi-component metal-cyanide hybrid coordination polymers, with which we have successfully prepared porous Fe2O3@NixCo3-xO4 nanocubes, one of the potential anode materials for lithium-ion batteries, such a simple and scalable approach could also be applied to the synthesis of other nanomaterials for energy storage devices.Herein, we demonstrate a novel and simple two-step process for preparing LiCoO2 nanocrystals by using a Prussian blue analogue Co3[Co(CN)6]2 as a precursor. The resultant LiCoO2 nanoparticles possess single crystalline nature and good uniformity with an average size of ca. 360 nm. The unique nanostructure of LiCoO2 provides relatively shorter Li+ diffusion pathways, thus facilitating the fast kinetics of electrochemical reactions. As a consequence, high reversible capacity, excellent cycling stability and rate capability are achieved with these nanocrystals as cathodes for lithium storage. The LiCoO2 nanocrystals deliver specific capacities of 154.5, 135.8, 119, and 100.3 mA h g-1 at 0.2, 0.4, 1, and 2 C rates, respectively. Even at a high current density of 4 C, a reversible capacity of 87 mA h g-1 could be maintained. Importantly, a capacity retention of 83.4% after 100 cycles is achieved at a constant discharge rate of 1 C. Furthermore, owing to facile control of the morphology and size of Prussian blue analogues by varying process parameters, as well as the tailored design of multi-component metal-cyanide hybrid coordination polymers, with which we have successfully prepared porous Fe2O3@NixCo3-xO4 nanocubes, one of the potential anode materials for lithium-ion batteries, such a simple and scalable approach could also be applied to the synthesis of other nanomaterials for energy storage devices. Electronic supplementary information (ESI) available: Detailed experimental procedures and supplementary figures. See DOI: 10.1039/c3nr03289b

Nie, Ping; Shen, Laifa; Luo, Haifeng; Li, Hongsen; Xu, Guiyin; Zhang, Xiaogang

2013-10-01

203

Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals.  

PubMed

An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains was developed. The polymer was prepared by sequential Sonogashira reactions, and the product was soluble in polar and apolar solvents. The additive effects of metal salts on the polymer were examined in water and aqueous EtOH on the basis of UV-vis and CD spectra. The enhancement of the positive Cotton effect and hypochromism around 360 nm occurred by the addition of various metal salts, indicating the coordination of the cations to the amide side chains of the polymer to stabilise the helical structure. Among them, rare-earth metal salts, especially Sc(OTf)3 showed more efficient additive effects probably because of its strong coordination ability even in water. Positive cooperativity was observed for the coordination of Sc(OTf)3 to the polymer in aqueous EtOH. PMID:25473810

Makida, Hiroki; Abe, Hajime; Inouye, Masahiko

2014-12-01

204

Coordination polymer submicrospheres: fast microwave synthesis and their conversion under different atmospheres.  

PubMed

Rare earth (RE) based coordination polymer (CP) submicrospheres have been prepared from pyridine-2,5-dicarboxylic acid and RE(NO3)3 via a facile microwave heating method in 5 min, with N,N-dimethylformamide (DMF) as solvent. The submicrospheres have diameters of 100-400 nm. Furthermore, the surface of the microspheres is smooth and the microspheres are solid. Several CP submicrospheres (RE = La, Gd, Y) were selected and calcined under different atmospheres (including air, N2, and NH3). After calcination in air at 550 °C for 4 h, rare earth oxide (RE2O3) submicrospheres were obtained. On calcination under an N2 atmosphere, LaN/La2O3/C composite spheres were obtained for La-based CPs. For Gd(Y)-based CPs, Gd2O3(Y2O3)/C composite spheres were obtained. Porous carbon submicrospheres were obtained after the removal of RE2O3 and REN from the composite spheres. Interestingly, under an NH3 atmosphere, La2O2CN2 submicrospheres were produced from the La-based CPs. In addition, the Gd-based and Y-based CPs submicrospheres gave Gd2O3/GdN/C and Y2O3/C submicrospheres, respectively. As examples of their potential applications, their upconversion properties and electrochemical properties of the as-prepared products were investigated. This facile microwave synthesis method may offer an attractive approach for the preparation of other RE-CP micro-/nanostructures, and many interesting materials may be derived. PMID:25083590

Zhong, Shengliang; Jing, Hongyu; Li, Yuan; Yin, Shungao; Zeng, Chenghui; Wang, Lei

2014-08-18

205

An unprecedented family of lanthanide-containing coordination polymers with highly tunable emission properties.  

PubMed

Reactions in water between mixtures of rare earth ions (Ln =Y, La-Tm, except Pm) and the sodium salt of terephthalic acid lead to an infinite family of isostructural heteropolynuclear coordination polymers. The monophasic character of the synthesized powders as well as the isostructurality of the heteropolynuclear compounds with the previously described mononuclear [Tb(2)(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity) are ascertained on the basis of the X-ray powder diffraction diagrams. One family of heterodinuclear compounds has been studied in detail, that is, [(La(2-x)Y(x))(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity) with 0 < or = x < or = 2. This study demonstrates the random character of the spatial distribution of the metallic ions. In order to demonstrate the high modularity of the physical properties, the solid-state luminescent properties of the compounds of general formula [(Eu(2-x)Tb(x))(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity) with 0 < or = x < or = 2 have been studied and compared to those of the corresponding mixtures of [(Eu(2))(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity) and [(Tb(2))(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity). In order to confirm the general character of these studies, the compound containing in equal proportions all 13 rare earth ions between La and Tm (except Pm) plus Y has been synthesized and characterized. At last, the solid-state luminescent properties of compounds belonging to the ternary system [(Ce(2-x-y)Eu(x)Tb(y))(C(8)H(4)O(4))(3)(H(2)O)(4)](infinity) with x + y < or = 2 are briefly described. PMID:19265391

Kerbellec, N; Kustaryono, D; Haquin, V; Etienne, M; Daiguebonne, C; Guillou, O

2009-04-01

206

[2D correlation spectral study of a coordination polymer [Eu(PCPOA)3 (H2O)]n].  

PubMed

A novel two dimensional coordination polymer [Eu(PCPOA)3 (H2O)], was synthesized under hydrothermal condition. Based on the determination of the structure, the 2D correlation FTIR spectra with the perturbation of magnetism and the 2D correlation fluorescence spectra with the perturbation of temperature were investigated. The energy bonds were calculated using CASTEP Program of Material studio. The Europium ions are nine-coordinated and the ligands adopted two different modes to connect the Eu3+ ions to 2D layer structure. The study of the 2D-FTIR reveals that the carboxylates coordinate with the center ions not only as monodentate, but also as bidentate chelate. The 2D fluorescence spectra indicates that the transition of (5)D0-->(7)F2 is influenced intensively by the perturbation of temperature. PMID:17655085

Sun, Rui-qing; Zhang, Han-hui; Cao, Yan-ning; Chen, Yi-ping; Yang, Qi-yu; Wang, Zhi-yang

2007-05-01

207

Quasi-one-dimensional optical lattices for soliton manipulation.  

PubMed

Based on angular spectrum engineering, we report the generation of optical lattices whose two-dimensional transverse nondiffracting pattern can be reduced to a quasi-one-dimensional intensity structure formed by either a single or multiple parallel channels. Remarkably, many features for each channel such as its maximum intensity, modulation, width, or separation among channels, can be controlled and modified in order to meet the requirements of particular applications. In particular, we demonstrate that these lattices can provide useful schemes for soliton routing and steering. We demonstrate the existence domain of ground-state solitons for the single quasi-one-dimensional lattice, and we show that these nondiffracting beams allow "push and pull" dynamics among the neighbor solitons propagated along the nondiffracting channels generated. PMID:25490515

Lopez-Aguayo, Servando; Ruelas-Valdez, Cesar; Perez-Garcia, Benjamin; Ortiz-Ambriz, Antonio; Hernandez-Aranda, Raul I; Gutiérrez-Vega, Julio C

2014-11-15

208

Explosive Disruption of Polytropes: a One Dimensional Hydrodynamic Calculation  

E-print Network

We study explosions of stars using a one-dimensional Lagrangian hydrodynamics code. We calculate how much mass is liberated as a function of the energy of explosion for a variety of pre-explosion stellar structures and for equations of state with a range of radiation-to-gas pressure ratios. The results show that simple assumptions about the amount of mass lost in an explosion can be quite inaccurate, and that even one-dimensional stars exhibit a rich phenomenology. The mass loss fraction rises from about 50 to 100 per cent as a function of the explosion energy in an approximately discontinuous manner. Combining our results with those of other, more realistic models, we suggest that Nova Scorpii (J1655-40) may have experienced significant mass fallback because the explosion energy was less than the critical value. We infer that the original progenitor was less than twice the mass of today's remnant.

Mark Wyman; David Chernoff; Ira Wasserman

2004-07-27

209

Chemically Reacting One-Dimensional Gas-Particle Flows  

NASA Technical Reports Server (NTRS)

The governing equations for the one-dimensional flow of a gas-particle system are discussed. Gas-particle effects are coupled via the system momentum and energy equations with the gas assumed to be chemically frozen or in chemical equilibrium. A computer code for calculating the one-dimensional flow of a gas-particle system is discussed and a user's input guide presented. The computer code provides for the expansion of the gas-particle system from a specified starting velocity and nozzle inlet geometry. Though general in nature, the final output of the code is a startline for initiating the solution of a supersonic gas-particle system in rocket nozzles. The startline includes gasdynamic data defining gaseous startline points from the nozzle centerline to the nozzle wall and particle properties at points along the gaseous startline.

Tevepaugh, J. A.; Penny, M. M.

1975-01-01

210

Robust one-dimensional metallic band structure of silicide nanowires.  

PubMed

Angle-resolved photoemission (ARP) is employed to investigate the electronic structure of an extremely anisotropic form of nanocrystals--GdSi(2-x) nanowires on Si(100). Using a stepped Si(100) surface, a well-ordered and uniformly oriented array of nanowires is formed along the step edges as confirmed by diffraction and microscopy. The ARP measurement discloses two distinct electronic bands near the Fermi level, which disperse one dimensionally along the nanowires. These bands are metallic with the electron filling of 1/4 and 2/5, respectively, and with the effective mass close to that of a free electron along the wires. The metallicity is robust down to 20 K, in contrast to metallic surface atomic chain systems, paving a way to further studies on one-dimensional physics of metallic nanowires. PMID:16384071

Yeom, H W; Kim, Y K; Lee, E Y; Ryang, K-D; Kang, P G

2005-11-11

211

Quantum Phase Transition in One-Dimensional Commensurate Frenkel–Kontorova Model  

NASA Astrophysics Data System (ADS)

We have studied the one-dimensional commensurate quantum Frenkel–Kontorova model by using a density-matrix renormalization group (DMRG) algorithm. The focus has been on its properties of entanglement, coordinate correlation, ground-state energy and energy gap between the ground state and the first excited state. It is demonstrated that a quantum phase transition (QPT) between the pinned and the sliding phases takes place as the quantum fluctuation, measured on the basis of an effective Planck constant tilde{hbar }, increases to a threshold value tilde{hbar }c.

Ma, Yongjun; Wang, Jiaxiang; Xu, Xinye; Wei, Qi; Kais, Sabre

2014-12-01

212

Phase Space Reduction of the One-Dimensional Fokker-Planck (Kramers) Equation  

NASA Astrophysics Data System (ADS)

A point-like particle of finite mass m, moving in a one-dimensional viscous environment and biased by a spatially dependent force, is considered. We present a rigorous mapping of the 1D Fokker-Planck (Kramers) equation, which determines evolution of the particle density in phase space, onto the spatial coordinate x. The result is the Smoluchowski equation, valid in the overdamped limit, m?0, with a series of corrections expanded in powers of m/ ?, ? denotes the friction coefficient. The corrections are determined unambiguously within the recurrence mapping procedure. The method and the results are interpreted on the simplest model with no field and on the damped harmonic oscillator.

Kalinay, Pavol; Percus, Jerome K.

2012-09-01

213

One-dimensional velocity model of the Middle Kura Depresion from local earthquakes data of Azerbaijan  

NASA Astrophysics Data System (ADS)

We present the method for determining the velocity model of the Earth's crust and the parameters of earthquakes in the Middle Kura Depression from the data of network telemetry in Azerbaijan. Application of this method allowed us to recalculate the main parameters of the hypocenters of the earthquake, to compute the corrections to the arrival times of P and S waves at the observation station, and to significantly improve the accuracy in determining the coordinates of the earthquakes. The model was constructed using the VELEST program, which calculates one-dimensional minimal velocity models from the travel times of seismic waves.

Yetirmishli, G. C.; Kazimova, S. E.; Kazimov, I. E.

2011-09-01

214

Effective Bragg conditions in a one-dimensional quasicrystal.  

PubMed

We present occurrence of the effective Bragg conditions with wide gapwidth and high reflectance in a Fibonacci superlattice, which is a typical one-dimensional quasicrystal. In the Fibonacci material, the number of effective Bragg conditions is two rather than one which appears in traditional periodic structures. Based on the effective Bragg conditions, this study proposes existence of omnidirectional, wideband and high reflectance in the quasiperiodic materials analogous to that in traditional materials. PMID:23187516

Hsueh, W J; Chang, C H; Cheng, Y H; Wun, S J

2012-11-19

215

Beyond the Born approximation in one-dimensional profile reconstruction  

NASA Astrophysics Data System (ADS)

A new method of one-dimensional profile reconstruction is presented. The method is based on an extension to the Born approximation and relates measurements of the scattered field to the Fourier transform of the slab profile. Since the Born and our new approximations are most valid at low frequency, we utilize superresolution to recover high-frequency information and then invert for the slab profile. Finally, we vary different parameters and examine the resulting reconstructions. approximation, profile reconstruction, superresolution.

Trantanella, Charles J.; Dudley, Donald G.; Nabulsi, Khalid A.

1995-07-01

216

Harmonic oscillator in a one-dimensional box  

E-print Network

We study a harmonic molecule confined to a one--dimensional box with impenetrable walls. We explicitly consider the symmetry of the problem for the cases of different and equal masses. We propose suitable variational functions and compare the approximate energies given by the variation method and perturbation theory with accurate numerical ones for a wide range of values of the box length. We analyze the limits of small and large box size.

Paolo Amore; Francisco M. Fernandez

2009-07-31

217

Growth of one-dimensional single-crystalline hydroxyapatite nanorods  

NASA Astrophysics Data System (ADS)

A facile, effective and template/surfactant-free hydrothermal route in the presence of sodium bicarbonate was developed to synthesize highly uniform single-crystalline hydroxyapatite (HA) nanorods with the lengths of several hundred nanometers and aspect ratio up to ˜20. One dimensional (1-D) growth and aspect ratio could be controlled by hydrothermal reaction time and temperature. The longitudinal axis, also the growth direction of the nanorods, is parallel to the [001] direction of HA hexagonal crystal structure.

Ren, Fuzeng; Ding, Yonghui; Ge, Xiang; Lu, Xiong; Wang, Kefeng; Leng, Yang

2012-06-01

218

On numerical modeling of one-dimensional geothermal histories  

USGS Publications Warehouse

Numerical models of one-dimensional geothermal histories are one way of understanding the relations between tectonics and transient thermal structure in the crust. Such models can be powerful tools for interpreting geochronologic and thermobarometric data. A flexible program to calculate these models on a microcomputer is available and examples of its use are presented. Potential problems with this approach include the simplifying assumptions that are made, limitations of the numerical techniques, and the neglect of convective heat transfer. ?? 1989.

Haugerud, R.A.

1989-01-01

219

Unusual conductance collapse in one-dimensional quantum structures  

Microsoft Academic Search

We report an unusual insulating state in one-dimensional quantum wires with a non-uniform confinement potential. The wires consist of a series of closely spaced split gates in high mobility GaAs\\/AlGaAs heterostructures. At certain combinations of wire widths, the conductance abruptly drops over three orders of magnitude, to zero on a linear scale. Two types of collapse are observed, one occurring

K J Thomas; D L Sawkey; M Pepper; W R Tribe; I Farrer; M Y Simmons; D A Ritchie

2004-01-01

220

One-Dimensional Packet Classification Using Pipelined Multibit Tries  

Microsoft Academic Search

We propose a heuristic for the construction of variable-stride multibit tries. These multibit tries are suitable for one-dimensional packet classification using a pipelined architecture. The variable-stride tries constructed by our heuristic require significantly less per-stage memory than required by optimal pipelined fixed-stride tries. We also develop a tree packing heuristic, which dramatically reduces per-stage memory required by fixed- and variable-stride

Wencheng Lu; Sartaj Sahni

221

One-dimensional description of cylindrically symmetric laser beams: application to bessel-type nondiffracting beams.  

PubMed

We introduce a new representation of coherent laser beams that are usually described in circular cylindrical coordinates. This representation is based on the decomposition of a laser beam of a given azimuthal order into beams exhibiting Cartesian symmetry. These beams, which we call constituent waves, diffract along only one of their transverse dimensions and propagate noncollinearly with the propagation axis. A cylindrically symmetric laser beam is then considered a coherent superposition of constituent waves and is represented by an integral over an angular variable. Such a representation allows for the introduction of the propagation factor M2, defined in terms of one-dimensional root-mean-square (rms) quantities, in the treatment of two-dimensional beams. The representation naturally leads to the definition of a new rms parameter that we call the quality factor Q. It is shown that the quality factor defines in quantitative terms the nondiffracting character of a laser beam. The representation is first applied to characterize Laguerre-Gauss beams in terms of these one-dimensional rms parameters. This analysis reveals an asymptotic link between Laguerre-Gauss beams and one-dimensional Hermite-Gauss beams in the limit of high azimuthal orders. The representation is also applied to Bessel-Gauss beams and demonstrates the geometrical and one-dimensional characters of the Bessel-Gauss beams that propagate in a nondiffracting regime. By using two separate rms parameters, Q and M2, our approach gives an alternative way to describe laser beam propagation that is especially well suited to characterize Bessel-type nondiffracting beams. PMID:16053148

Rousseau, Guy; Gay, David; Piché, Michel

2005-07-01

222

Proton dynamics of two-dimensional oxalate-bridged coordination polymers.  

PubMed

A two-dimensional porous coordination polymer (NH4)2{HOOC(CH2)4COOH}[Zn2(C2O4)3] (abbreviated as (NH4)2(adp)[Zn2(ox)3] (adp = adipic acid, ox = oxalate)), which accommodates water molecules between the [Zn2(ox)3] layers, is highly remarked as a new type of crystalline proton conductor. In order to investigate its phase behavior and the proton conducting mechanism, we have performed adiabatic calorimetry, neutron diffraction, and quasi-elastic neutron scattering experiments on a fully hydrated sample (NH4)2(adp)[Zn2(ox)3]·3H2O with the highest proton conductivity (8 × 10(-3) S cm(-1), 25 °C, 98% RH). Its isostructural derivative K2(adp)[Zn2(ox)3]·3H2O was also measured to investigate the role of ammonium ions. (NH4)2(adp)[Zn2(ox)3]·3H2O and K2(adp)[Zn2(ox)3]·3H2O exhibit higher order transitions at 86 K and 138 K, respectively. From the magnitude of the transition entropy, the former is of an order-disorder type while the latter is of a displacive type. (NH4)2(adp)[Zn2(ox)3]·3H2O has four Debye-type relaxations and K2(adp)[Zn2(ox)3]·3H2O has two similar relaxations above each transition temperature. The two relaxations of (NH4)2(adp)[Zn2(ox)3]·3H2O with very small activation energies (?Ea < 5 kJ mol(-1)) are due to the rotational motions of ammonium ions and play important roles in the proton conduction mechanism. It was also found that the protons in (NH4)2(adp)[Zn2(ox)3]·3H2O are carried through a Grotthuss mechanism. We present a discussion on the proton conducting mechanism based on the present structural and dynamical information. PMID:25019223

Miyatsu, Satoshi; Kofu, Maiko; Nagoe, Atsushi; Yamada, Takeshi; Sadakiyo, Masaaki; Yamada, Teppei; Kitagawa, Hiroshi; Tyagi, Madhusudan; García Sakai, Victoria; Yamamuro, Osamu

2014-08-28

223

Novel 1D coordination polymer {Tm(Piv)3}n: Synthesis, structure, magnetic properties and thermal behavior  

NASA Astrophysics Data System (ADS)

The new 1D coordination polymer {Tm(Piv)3}n (1), where Piv=OOCBut-, was synthesized in high yield (>95%) by the reaction of thulium acetate with pivalic acid in air at 100 °C. According to the X-ray diffraction data, the metal atoms in compound 1 are in an octahedral ligand environment unusual for lanthanides. The magnetic and luminescence properties of polymer 1, it's the solid-phase thermal decomposition in air and under argon, and the thermal behavior in the temperature range of -50…+50 °C were investigated. The vaporization process of complex 1 was studied by the Knudsen effusion method combined with mass-spectrometric analysis of the gas-phase composition in the temperature range of 570-680 K.

Fomina, Irina; Dobrokhotova, Zhanna; Aleksandrov, Grygory; Emelina, Anna; Bykov, Mikhail; Malkerova, Irina; Bogomyakov, Artem; Puntus, Lada; Novotortsev, Vladimir; Eremenko, Igor

2012-01-01

224

Effect of different carboxylates on two Ag(I) coordination polymers with 2,5-dimethylpyrazine ligand  

NASA Astrophysics Data System (ADS)

Two new metal-organic framework namely, [(btc)]n (1), and [ (2), have been synthesized and structurally characterized. Compound 1 is a 3D structure incorporating ?5-(?1,?1):(?1,?1):(?1,?1) btc and ?2-N1,N1,?2-N2,N3 dmpyz ligands. In compound 2, the ?5-?1:?2:?3:?1 pta and the dmpyz ligands link the [Ag4O2] units into a 2D structure. It is noteworthy that the Ag⋯Ag interactions were observed in the two coordination polymers. The results show that the structural diversity of the polymers is mainly attributed to the usage of diverse ancillary carboxylate ligands. The thermal stabilities and photoluminescence behaviors were addressed.

Wang, Zhan-Hui; Wang, Dan-Feng; Zhang, Ting; Huang, Rong-Bin; Zheng, Lan-Sun

2014-05-01

225

One-Dimensional Scanning Approach to Shock Sensing  

NASA Technical Reports Server (NTRS)

Measurement tools for high speed air flow are sought both in industry and academia. Particular interest is shown in air flows that exhibit aerodynamic shocks. Shocks are accompanied by sudden changes in density, pressure, and temperature. Optical detection and characterization of such shocks can be difficult because the medium is normally transparent air. A variety of techniques to analyze these flows are available, but they often require large windows and optical components as in the case of Schlieren measurements and/or large operating powers which precludes their use for in-flight monitoring and applications. The one-dimensional scanning approach in this work is a compact low power technique that can be used to non-intrusively detect shocks. The shock is detected by analyzing the optical pattern generated by a small diameter laser beam as it passes through the shock. The optical properties of a shock result in diffraction and spreading of the beam as well as interference fringes. To investigate the feasibility of this technique a shock is simulated by a 426 m diameter optical fiber. Analysis of results revealed a direct correlation between the optical fiber or shock location and the beam s diffraction pattern. A plot of the width of the diffraction pattern vs. optical fiber location reveals that the width of the diffraction pattern was maximized when the laser beam is directed at the center of the optical fiber. This work indicates that the one-dimensional scanning approach may be able to determine the location of an actual shock. Near and far field effects associated with a small diameter laser beam striking an optical fiber used as a simulated shock are investigated allowing a proper one-dimensional scanning beam technique.

Tokars, Roger; Adamovsky, Girgory; Floyd, Bertram

2009-01-01

226

Resonant states in an attractive one dimensional cusp potential  

E-print Network

We solve the two-component Dirac equation in the presence of a spatially one dimensional symmetric attractive cusp potential. The components of the spinor solution are expressed in terms of Whittaker functions. We compute the bound states solutions and show that, as the potential amplitude increases, the lowest energy state sinks into the Dirac sea becoming a resonance. We characterize and compute the lifetime of the resonant state with the help of the phase shift and the Breit-Wigner relation. We discuss the limit when the cusp potential reduces to a delta point interaction.

Victor M. Villalba; Luis A. Gonzalez-Diaz

2007-02-22

227

One-dimensional ultracold medium of extreme optical depth.  

PubMed

We report on the preparation of a one-dimensional ultracold medium in a hollow-core photonic crystal fiber, reaching an effective optical depth of 1000(150). We achieved this extreme optical depth by transferring atoms from a magneto-optical trap into a far-detuned optical dipole trap inside the hollow-core fiber, yielding up to 2.5(3)×10(5) atoms inside the core with a loading efficiency of 2.5(6)%. The preparation of an ultracold medium of such huge optical depth paves the way toward new applications in quantum optics and nonlinear optics. PMID:24487836

Blatt, Frank; Halfmann, Thomas; Peters, Thorsten

2014-02-01

228

Parallel solution of sparse one-dimensional dynamic programming problems  

NASA Technical Reports Server (NTRS)

Parallel computation offers the potential for quickly solving large computational problems. However, it is often a non-trivial task to effectively use parallel computers. Solution methods must sometimes be reformulated to exploit parallelism; the reformulations are often more complex than their slower serial counterparts. We illustrate these points by studying the parallelization of sparse one-dimensional dynamic programming problems, those which do not obviously admit substantial parallelization. We propose a new method for parallelizing such problems, develop analytic models which help us to identify problems which parallelize well, and compare the performance of our algorithm with existing algorithms on a multiprocessor.

Nicol, David M.

1989-01-01

229

One-dimensional intense laser pulse solitons in a plasma  

SciTech Connect

A general analytical framework is developed for the nonlinear dispersion relations of a class of large amplitude one-dimensional isolated envelope solitons for modulated light pulse coupled to electron plasma waves, previously investigated numerically [Kozlov {ital et al.}, Zh. Eksp. Teor. Fiz. {bold 76}, 148 (1979); Kaw {ital et al.}, Phys. Rev. Lett. {bold 68}, 3172 (1992)]. The analytical treatment of weakly nonlinear solitons [Kuehl and Zhang, Phys. Rev. E {bold 48}, 1316 (1993)] is extended to the strongly nonlinear limit. {copyright} {ital 1997 American Institute of Physics.}

Sudan, R.N.; Dimant, Y.S.; Shiryaev, O.B. [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)] [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)

1997-05-01

230

Temporal coherence of one-dimensional nonequilibrium quantum fluids  

NASA Astrophysics Data System (ADS)

We theoretically investigate the time dependence of the first-order coherence function for a one-dimensional driven dissipative nonequilibrium condensate. Simulations on the generalized Gross-Pitaevskii equation show that the characteristic time scale of exponential decay agrees with the linearized Bogoliubov theory in the regime of large interaction energy. For very weak interactions, the temporal correlation deviates from the linear theory, and instead respects the dynamic scaling of the Kardar-Parisi-Zhang universality class. This nonlinear dynamics is found to be quantitatively captured by a noisy Kuramoto-Sivashinsky equation for the phase dynamics.

Ji, Kai; Gladilin, Vladimir N.; Wouters, Michiel

2015-01-01

231

Quantum Criticality of Quasi-One-Dimensional Topological Anderson Insulators  

NASA Astrophysics Data System (ADS)

We present an analytic theory of quantum criticality in the quasi-one-dimensional topological Anderson insulators of class AIII and BDI. We describe the systems in terms of two parameters (g, ?) representing localization and topological properties, respectively. Surfaces of half-integer valued ? define phase boundaries between distinct topological sectors. Upon increasing system size, the two parameters exhibit flow similar to the celebrated two-parameter flow describing the class A quantum Hall insulator. However, unlike the quantum Hall system, an exact analytical description of the entire phase diagram can be given. We check the quantitative validity of our theory by comparison to numerical transfer matrix computations.

Altland, Alexander; Bagrets, Dmitry; Fritz, Lars; Kamenev, Alex; Schmiedt, Hanno

2014-05-01

232

Programmers manual for a one-dimensional Lagrangian transport model  

USGS Publications Warehouse

A one-dimensional Lagrangian transport model for simulating water-quality constituents such as temperature, dissolved oxygen , and suspended sediment in rivers is presented in this Programmers Manual. Lagrangian transport modeling techniques, the model 's subroutines, and the user-written decay-coefficient subroutine are discussed in detail. Appendices list the program codes. The Programmers Manual is intended for the model user who needs to modify code either to adapt the model to a particular need or to use reaction kinetics not provided with the model. (Author 's abstract)

Schoellhamer, D.H.; Jobson, H.E.

1986-01-01

233

End states in one-dimensional atom chains.  

PubMed

End states--the zero-dimensional analogs of the two-dimensional states that occur at a crystal surface--were observed at the ends of one-dimensional atom chains that were self-assembled by depositing gold on the vicinal Si(553) surface. Scanning tunneling spectroscopy measurements of the differential conductance along the chains revealed quantized states in isolated segments with differentiated states forming over end atoms. A comparison to a tight-binding model demonstrated how the formation of electronic end states transforms the density of states and the energy levels within the chains. PMID:15692047

Crain, J N; Pierce, D T

2005-02-01

234

Electronic properties of a one-dimensional hierarchical system  

NASA Astrophysics Data System (ADS)

The electronic properties of a one-dimensional hierarchical system are studied using a new type of tight-binding model with a hierarchical array of hopping-matrix elements. By means of a renormalization-group approach the energy spectrum and wave functions are obtained. The spectrum constitutes a Cantor set whose global scaling properties are calculated. A multifractal analysis of the wave functions at the center and at the edge of the spectrum is performed. The relevance of the present work to other models is discussed.

Roman, H. Eduardo

1987-11-01

235

Breakdown of Thermalization in Finite One-Dimensional Systems  

SciTech Connect

We use quantum quenches to study the dynamics and thermalization of hard core bosons in finite one-dimensional lattices. We perform exact diagonalizations and find that, far away from integrability, few-body observables thermalize. We then study the breakdown of thermalization as one approaches an integrable point. This is found to be a smooth process in which the predictions of standard statistical mechanics continuously worsen as the system moves toward integrability. We establish a direct connection between the presence or absence of thermalization and the validity or failure of the eigenstate thermalization hypothesis, respectively.

Rigol, Marcos [Department of Physics, Georgetown University, Washington, D.C. 20057 (United States)

2009-09-04

236

Decay of fermionic quasiparticles in one-dimensional quantum liquids.  

PubMed

The low-energy properties of one-dimensional quantum liquids are commonly described in terms of the Tomonaga-Luttinger liquid theory, in which the elementary excitations are free bosons. To this approximation, the theory can be alternatively recast in terms of free fermions. In both approaches, small perturbations give rise to finite lifetimes of excitations. We evaluate the decay rate of fermionic excitations and show that it scales as the eighth power of energy, in contrast to the much faster decay of bosonic excitations. Our results can be tested experimentally by measuring the broadening of power-law features in the density structure factor or spectral functions. PMID:24483750

Matveev, K A; Furusaki, A

2013-12-20

237

One-dimensional Coulomb problem in Dirac materials  

E-print Network

We investigate the one-dimensional Coulomb potential with application to a class of quasirelativistic systems, so-called Dirac-Weyl materials, described by matrix Hamiltonians. We obtain the exact solution of the shifted and truncated Coulomb problems, with the wavefunctions expressed in terms of special functions (namely Whittaker functions), whilst the energy spectrum must be determined via solutions to transcendental equations. Most notably, there are critical bandgaps below which certain low-lying quantum states are missing in a manifestation of atomic collapse.

C. A. Downing; M. E. Portnoi

2014-11-21

238

Fast numerical method for modelling one-dimensional diffraction gratings  

SciTech Connect

Based on the generalised source method, a new method for calculating the light diffraction on one-dimensional dielectric diffraction gratings with an arbitrary profile is proposed. The method is an alternative to the widely used Fourier modal method because it possesses the same possibilities in defining different grating profiles; however, it has a significant advantage in calculating complex-shaped gratings because it requires many fewer mathematical operations. The applicability of the method is shown by comparing the calculation results by this method with the results obtained by the conventional methods of light diffraction calculation on the gratings. (laser applications and other topics in quantum electronics)

Shcherbakov, A A; Tishchenko, A V [MEPhI National Research Nuclear University, Moscow (Russian Federation)

2010-08-27

239

Lateral shift in one-dimensional quasiperiodic chiral photonic crystal  

NASA Astrophysics Data System (ADS)

We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.

Da, Jian; Mo, Qi; Cheng, Yaokun; Liu, Taixiang

2015-02-01

240

Computer model of one-dimensional equilibrium controlled sorption processes  

USGS Publications Warehouse

A numerical solution to the one-dimensional solute-transport equation with equilibrium-controlled sorption and a first-order irreversible-rate reaction is presented. The computer code is written in FORTRAN language, with a variety of options for input and output for user ease. Sorption reactions include Langmuir, Freundlich, and ion-exchange, with or without equal valance. General equations describing transport and reaction processes are solved by finite-difference methods, with nonlinearities accounted for by iteration. Complete documentation of the code, with examples, is included. (USGS)

Grove, D.B.; Stollenwerk, K.G.

1984-01-01

241

Bosonization approach to the one-dimensional Kondo lattice model  

E-print Network

The one-dimensional Kondo lattice model is investigated by using bosonization techniques and conformal field theory. In the half-filled band, the charge and spin gaps open for the anti-ferromagnetic Kondo coupling. Away from half-filling, the paramagnetic metallic state is characterized by the fixed point of Tomonaga-Luttinger liquid with the {\\it large} Fermi surface in accordance with known results. It is suggested that as the electron density approaches half-filling, both of spin and charge susceptibilities may show a divergence property.

S. Fujimoto; N. Kawakami

1994-10-18

242

One-dimensional model for the fractional quantum Hall effect  

NASA Astrophysics Data System (ADS)

A simple one-dimensional model is proposed, in which N spinless repulsively interacting fermions occupy M>N degenerate states. It is argued that the energy spectrum and the wavefunctions of this system strongly resemble the spectrum and wavefunctions of 2D electrons in the lowest Landau level (the problem of the Fractional Quantum Hall Effect). In particular, Laughlin-type wavefunctions describe ground states at filling factors v = N/M = 1/q, q odd.. Within this model the complimentary wavefunction for v=1-1/q is found explicitly, and extremely simple ground state wavefunctions for arbitrary odd-denominator filling factors are proposed.

Dyakonov, M. I.

2013-08-01

243

Electronic averaging of one-dimensional television pictures.  

PubMed

Often the data which one would like to record by means of a television system are only one-dimensional, for example, optical spectra or, in this case, picosecond light pulse measurement by the nonlinear photoelectric effect. For such data, a significant increase in signal-to-noise ratio and dynamic range can be obtained by averaging over the redundant dimension. A box-car system has been developed for performing such an average using the standard television raster. Particular attention was paid to the problem of accurate dc restoration of the video signal. PMID:20094307

Burnham, D C

1970-11-01

244

Constraint and gauge shocks in one-dimensional numerical relativity  

E-print Network

We study how different types of blow-ups can occur in systems of hyperbolic evolution equations of the type found in general relativity. In particular, we discuss two independent criteria that can be used to determine when such blow-ups can be expected. One criteria is related with the so-called geometric blow-up leading to gradient catastrophes, while the other is based upon the ODE-mechanism leading to blow-ups within finite time. We show how both mechanisms work in the case of a simple one-dimensional wave equation with a dynamic wave speed and sources, and later explore how those blow-ups can appear in one-dimensional numerical relativity. In the latter case we recover the well known ``gauge shocks'' associated with Bona-Masso type slicing conditions. However, a crucial result of this study has been the identification of a second family of blow-ups associated with the way in which the constraints have been used to construct a hyperbolic formulation. We call these blow-ups ``constraint shocks'' and show that they are formulation specific, and that choices can be made to eliminate them or at least make them less severe.

Bernd Reimann; Miguel Alcubierre; José A. González; Darío Núñez

2005-03-03

245

Dislocation-mediated melting of one-dimensional Rydberg crystals  

SciTech Connect

We consider cold Rydberg atoms in a one-dimensional optical lattice in the Mott regime with a single atom per site at zero temperature. An external laser drive with Rabi frequency {Omega} and laser detuning {Delta} creates Rydberg excitations whose dynamics is governed by an effective spin-chain model with (quasi) long-range interactions. This system possesses intrinsically a large degree of frustration resulting in a ground-state phase diagram in the ({Delta},{Omega}) plane with a rich topology. As a function of {Delta}, the Rydberg blockade effect gives rise to a series of crystalline phases commensurate with the optical lattice that form a so-called devil's staircase. The Rabi frequency {Omega}, on the other hand, creates quantum fluctuations that eventually lead to a quantum melting of the crystalline states. Upon increasing {Omega}, we find that generically a commensurate-incommensurate transition to a floating Rydberg crystal that supports gapless phonon excitations occurs first. For even larger {Omega}, dislocations within the floating Rydberg crystal start to proliferate and a second, Kosterlitz-Thouless-Nelson-Halperin-Young dislocation-mediated melting transition finally destroys the crystalline arrangement of Rydberg excitations. This latter melting transition is generic for one-dimensional Rydberg crystals and persists even in the absence of an optical lattice. The floating phase and the concomitant transitions can, in principle, be detected by Bragg scattering of light.

Sela, Eran; Garst, Markus [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, DE-50937 Koeln (Germany); Punk, Matthias [Physik Department, Technische Universitaet Muenchen, James-Franck-Strasse, DE-85748 Garching (Germany); Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-08-15

246

Metal coordination architectures of triazole-based ligands: Effect of the backbone of bridging ligands on the construction of polymers  

NASA Astrophysics Data System (ADS)

In our efforts to investigate the influence of the backbone of different triazole-based bridging ligands on the structure of their metal complexes, four new coordination polymers, {[Cu(L1)2(H2O)2]Cl2}n (1), [Cu(L2)2Cl2]n (2), [Co(L2)2(SCN)2]n (3), and [Cu(L3)2(NO3)2]n (4), (L1 = 1,2-bis(triazol-1-ylmethyl)benzene, L2 = 1,3-bis(triazol-1-ylmethyl)benzene, L3 = 1,4-bis(triazol-1-ylmethyl)benzene), have been synthesized. All the complexes have been structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Structural analyses show that 1 and 4 possess 2D coordination networks with (4,4) topology, and 1 shows a diagonal-diagonal inclined interpenetration. 2 and 3 are isostructural and feature 1D double chain, which further connected by C-H···Cl or ?···? weak interactions to form 2D supramolecular frameworks. The results show that the structures of ligands (with different non-coordination backbone spacers) play important roles in the formation of such coordination architectures. Furthermore, EPR (Electron Paramagnetic Resonance) spectra of CuII complexes (1, 2, and 4) have been investigated in the solid state at room temperature.

Du, Jian-Long; Hu, Tong-Liang; Bu, Xian-He

2012-04-01

247

Hydrothermal syntheses and structures of first examples of lanthanide 7,8,4?-tricarboxymethoxyisoflavone coordination polymers  

NASA Astrophysics Data System (ADS)

Two novel isostructure open frameworks of Ln(III), [Ln(L)(H 2O)·1.5H 2O] n, [Ln = Pr( 1), Eu( 2)], have been successfully synthesized using multifunctional organic compound 7,8,4'-tricarboxymethoxyisoflavone (L) as a linker through hydrothermal technique. Compounds 1 and 2 consist of 2D networks, which are further assembled into 3D architecture with 1D channels constructed by coordination bonds and the lattice water molecules array in lines occupying these voids via hydrogen bonds. In these compounds, L only exhibit one coordination mode coordinating to Ln(III), and four oxygen atoms from two carboxylate groups and two carboxymethoxy groups of one L coordinate to one Ln(III), simultaneously. The thermogravimetric analyses of these compounds show that the coordinated water and lattice water are lost in two steps, and the final residues are lanthanide oxides.

Wang, Yibo; Gao, Lihua; Han, Lijun; Zhang, Suojiang; Feng, Lujia

2009-12-01

248

Effect of substituent on dimensionality and properties in divalent metal isophthalate coordination polymers with a conformationally flexible dipyridylamide coligand  

NASA Astrophysics Data System (ADS)

Hydrothermal reaction of divalent metal nitrates and 3-pyridylmethylnicotinamide (3-pmna) with either isophthalic acid (H2iph) or 5-nitroisophthalic acid (H2nip) has afforded a series of four coordination polymer solids that were structurally characterized via single-crystal X-ray crystallography. [Ni(iph)(3-pmna)]n (1) and [Cd(iph)(3-pmna)]n (2) both exhibit a {M2(OCO)2} dimer-based 1-D ribbon topology with metal-metal contacts bridged by both ip and 3-pmna ligands. [Ni(nip)(3-pmna)]n (3) has the same topology as its unsubstituted congener 1, showing a null effect on the part of the nip nitro group. On the other hand [Cd(nip)(3-pmna)]n (4) exhibits a {Cd2O2} dimer-based 2-D (4,4) layer topology, a rare example of the nitro group imposing a higher dimensionality in the resulting coordination polymer. While 2 showed strong blue-violet luminescence, quenching mechanisms due to the nitro group rendered 4 non-luminescent. Thermal properties of these new materials are also investigated.

Torres Salgado, Maria D.; LaDuca, Robert L.

2015-01-01

249

Syntheses and structures of three heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid  

NASA Astrophysics Data System (ADS)

Three lanthanide-transition-metal coordination polymers, namely, [Er2L6(H2O)][Cu2I2] (1), [ErL3][CuI] (2), and [Dy2L6(BPDC)0.5(H2O)4][Cu3I2] (3) (HL=4-pyridin-3-yl-benzoic acid, H2BPDC=4,4?-biphenyldicarboxylic acid) have been made by reacting Ln2O3 and CuI with HL at different temperatures under hydrothermal conditions. All the complexes are characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1-3 all construct from dimeric {Ln2} and {Cu2} units and exhibit two types of the structural features: 1 is a two-dimensional layer, 2-3 are three-dimensional frameworks. Interestingly, the in situ formation of the BPDC ligand is found in the structure of 3. The distinct architectures of these complexes indicated that the reaction temperature plays an important role in the formation of higher dimensional coordination polymers.

Fang, Wei-Hui; Yang, Guo-Yu

2014-04-01

250

Synthesis, crystal structures and characterization of four coordination polymers based on 5-amino-2,4,6-triiodoisophthalic acid  

NASA Astrophysics Data System (ADS)

One homochiral 1D coordination polymer [Cu(ATIBDC)(2,2'-bipy)]·3H 2O·CH 3OH ( 1) and three achiral 1D coordination polymers: [Cd(ATIBDC)(2,2'-bipy)(H 2O)]·3H 2O ( 2), [Cd(ATIBDC)(phen)(H 2O)]·4H 2O ( 3), and [Mn(ATIBDC)(phen) 2]·5H 2O ( 4) have been synthesized and characterized (H 2ATIBDC=5-amino-2,4,6-triiodoisophthalic acid, 2,2'-bipy=2,2'-bipyridine, and phen=1,10-phenanthroline). Extended high dimensional network architectures are further constructed with the help of weak secondary interactions, such as hydrogen bonding, aromatic stacking, and halogen bonding (C-I… ? and C-I…N/O). Complex 1 crystallizes in the monoclinic system with chiral space group P2(1) and exhibits a right-handed 2 1 helical chain structure. The homochirality of 1 was confirmed by CD spectrum. Interestingly, two new configurations of decameric water cluster are found in 3 and 4. The acyclic tetrameric cluster (H 2O) 3(CH 3OH) in 1 and (H 2O) 4 in 2 array into highly ordered helical infinite chains. Thermal stabilities of all the complexes have been studied. Solid state fluorescent properties of the Cd(II) complexes have been explored.

Zhang, Kou-Lin; Chang, Yan; Zhang, Jing-Bo; Yuan, Li-Min; Deng, Ye; Diao, Guo-Wang; Ng, Seik Weng

2011-05-01

251

Four linear Cu(II)3 subunit-based coordination polymers with various inter-subunit connections, spin ground-states and intra-/inter-subunit magnetic couplings.  

PubMed

Four new 4-amino-1,2,4-triazole (atr)-based coordination polymers, {[Cu2(atr)(H2O)(?-OH)2(pa)]·H2O}n (), {[Cu3(atr)2(H2O)2(?-OH)2(npa)2]·2H2O}n (), {[Cu3(atr)5(dca)(?-OH)(ClO4)2](ClO4)2}n () and {[Cu3(atr)2(H2O)(?3-OH)(?-OH)2(spa)]·1.5H2O}n () (pa(2-) = phthalate, npa(2-) = 3-nitrophthalate, dca(-) = dicyanamide and spa(3-) = 4-sulfophthalate), were successfully obtained by varying the carboxylate- and cyanide-modified magnetic bridges. Structural determinations reveal that the former three samples are bent one-dimensional chains constructed from linear Cu(II)3 subunits and different inter-subunit connections. In , linear {Cu3(?-N1,N2-atr)2(?-OH)2}(4+) and {Cu3(?-COO)2(?-OH)2}(4+) subunits are alternately connected in a sharing-vertex manner to give a ferrimagnetic S = 1/2 spin ground-state. The linear {Cu3(?-N1,N2-atr)2(?-OH)2}(4+) building block of is repeatedly bridged by pairs of single-atom bridging carboxylate groups of the npa(2-) ligand leading to a paramagnetic S = 1/2 spin ground-state. By contrast, each linear {Cu3(?-N1,N2-atr)4}(6+) core in is periodically propagated by four-fold heterobridges (?-OH(-), ?-ClO4(-), ?-N1,N2-atr and ?-dca(-)) to generate an overall diamagnetic S = 0 spin ground-state. Complex is a three-dimensional pillared-layer framework composed of linear {Cu3(?-N1,N2-atr)2(?-OH)2}(4+)-based layers and ditopic spa(3-) connectors, which exhibits a ferrimagnetic S = 1/2 spin ground-state and a metamagnetic transition resulting from the competition between the weak interchain/interlayer antiferromagnetic interaction and the enhanced external magnetic field. In addition, different intra- and inter-subunit magnetic strengths are observed in with the coupling constants 182 < -Jintra < 43 and -127 < Jinter < 51.2 cm(-1). These interesting magnetostructural results are significant and helpful for the cyclic polyazolate-based magnetic materials. PMID:25581907

Yang, En-Cui; Liu, Zhong-Yi; Chen, Si-Hang; Su, Yan-Hong; Zhang, Yan-Yan; Zhao, Xiao-Jun

2015-02-01

252

Strongly-Refractive One-Dimensional Photonic Crystal Prisms  

NASA Technical Reports Server (NTRS)

One-dimensional (1D) photonic crystal prisms can separate a beam of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a ID photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1 D photonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The ID photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

Ting, David Z. (Inventor)

2004-01-01

253

Out-of-equilibrium one-dimensional disordered dipole chain  

NASA Astrophysics Data System (ADS)

We consider a chain of one-dimensional dipole moments connected to two thermal baths with different temperatures. The system is in nonequilibrium steady state and heat flows through it. Assuming that fluctuation of the dipole moment is a small parameter, we develop an analytically solvable model for the problem. The effect of disorder is introduced by randomizing the positions of the dipole moments. We show that the disorder leads to Anderson-like transition from conducting to a thermal insulating state of the chain. It is shown that considered chain supports both ballistic and diffusive heat transports depending on the strength of the disorder. We demonstrate that nonequilibrium leads to the emergence of the long-range order between dipoles along the chain and make the conjecture that the interplay between nonequilibrium and next-to-nearest-neighbor interactions results in the emergence of long-range correlations in low-dimensional classical systems.

Dolgikh, Anton V.; Kosov, Daniel S.

2013-07-01

254

Magnons in one-dimensional k-component Fibonacci structures  

SciTech Connect

We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: S{sub n}{sup (k)}=S{sub n?1}{sup (k)}S{sub n?k}{sup (k)}?(n?k=0,1,2,…), where S{sub n}{sup (k)} is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.

Costa, C. H., E-mail: carloshocosta@hotmail.com [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M. S. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)

2014-05-07

255

Local characterization of one-dimensional topologically ordered states  

NASA Astrophysics Data System (ADS)

We consider one-dimensional Hamiltonian systems whose ground states display symmetry-protected topological order. We show that ground states within the topological phase cannot be connected with each other through local operations and classical communication between a bipartition of the system. Our claim is demonstrated by analyzing the entanglement spectrum and Rényi entropies of different physical systems that provide examples for symmetry-protected topological phases. Specifically, we consider the spin-1/2 cluster-Ising model and a class of spin-1 models undergoing quantum phase transitions to the Haldane phase. Our results provide a probe for symmetry-protected topological order. Since the picture holds even at the system's local scale, our analysis can serve as a local experimental test for topological order.

Cui, Jian; Amico, Luigi; Fan, Heng; Gu, Mile; Hamma, Alioscia; Vedral, Vlatko

2013-09-01

256

Magnons in one-dimensional k-component Fibonacci structures  

NASA Astrophysics Data System (ADS)

We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: Sn(k)=Sn-1(k)Sn-k(k) (n ?k=0,1,2,…), where Sn(k) is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.

Costa, C. H.; Vasconcelos, M. S.

2014-05-01

257

Nonlinearity effects on conductance statistics in one dimensional disordered systems  

NASA Astrophysics Data System (ADS)

We investigate numerically the effect of non-linear interaction on conductance statistics in one dimensional disordered systems with ? peak potentials. It is shown that the non-linearity can either localize or delocalize the electronic states depending on its sign. For an attractive nonlinear interaction, we found that the mean conductance decays as g?L. The exponent ? is found to be sensitive to the kind of the potential. It seems to be independent of the strength of the non-linearity in the case of disordered barrier potentials, while it varies with this strength for well and mixed potentials. The conductance probability distribution shows a deviation from its log-normal form (linear case) when the nonlinearity is increased and the fluctuations of conductance decrease indicating the delocalization of the eigenstates.

Senouci, Khaled

2014-11-01

258

Loschmidt echo in one-dimensional interacting Bose gases  

SciTech Connect

We explore Loschmidt echo in two regimes of one-dimensional interacting Bose gases: the strongly interacting Tonks-Girardeau (TG) regime, and the weakly interacting mean-field regime. We find that the Loschmidt echo of a TG gas decays as a Gaussian when small (random and time independent) perturbations are added to the Hamiltonian. The exponent is proportional to the number of particles and the magnitude of a small perturbation squared. In the mean-field regime the Loschmidt echo shows richer behavior: it decays faster for larger nonlinearity, and the decay becomes more abrupt as the nonlinearity increases; it can be very sensitive to the particular realization of the noise potential, especially for relatively small nonlinearities.

Lelas, K.; Seva, T.; Buljan, H. [Faculty of Electrical Engineering Mechanical Engineering and Naval Architecture, University of Split, Rudjera Boskovica BB, 21000 Split (Croatia); Department of Physics, University of Zagreb, Bijenicka c. 32, 10000 Zagreb (Croatia)

2011-12-15

259

Luminescent one-dimensional nanostructures of perylene bisimides  

NASA Astrophysics Data System (ADS)

Perylene bisimides form a unique class of organic semiconductors, in this investigation two symmetrical perylene bisimides caped with 1-butyl (B-PTCDI) and 4,4-diethoxybutyl (DB-PTCDI) have been synthesized and characterized. The compounds self-assembled as a network of nanobelts and nanorods in the solution based self-assembly process. Morphologies of these self-assembled structures were characterized by optical, fluorescence, scanning and transmission electronic microscopic techniques. One-dimensional self-assemblies of B-PTCDI and DB-PTCDI molecules are due to the strong ?-? stacking ability of perylene core and assistance given by the side chains and solvent. Observed molecular self-assembly and electronic properties of the molecules. The observed self-assembly was supported by molecular modeling studies using density functional theory.

Boobalan, G.; Imran, P. K. M.; Nagarajan, S.

2013-09-01

260

Luminescent one-dimensional nanostructures of perylene bisimides.  

PubMed

Perylene bisimides form a unique class of organic semiconductors, in this investigation two symmetrical perylene bisimides caped with 1-butyl (B-PTCDI) and 4,4-diethoxybutyl (DB-PTCDI) have been synthesized and characterized. The compounds self-assembled as a network of nanobelts and nanorods in the solution based self-assembly process. Morphologies of these self-assembled structures were characterized by optical, fluorescence, scanning and transmission electronic microscopic techniques. One-dimensional self-assemblies of B-PTCDI and DB-PTCDI molecules are due to the strong ?-? stacking ability of perylene core and assistance given by the side chains and solvent. Observed molecular self-assembly and electronic properties of the molecules. The observed self-assembly was supported by molecular modeling studies using density functional theory. PMID:23743040

Boobalan, G; Imran, P K M; Nagarajan, S

2013-09-01

261

Users manual for a one-dimensional Lagrangian transport model  

USGS Publications Warehouse

A Users Manual for the Lagrangian Transport Model (LTM) is presented. The LTM uses Lagrangian calculations that are based on a reference frame moving with the river flow. The Lagrangian reference frame eliminates the need to numerically solve the convective term of the convection-diffusion equation and provides significant numerical advantages over the more commonly used Eulerian reference frame. When properly applied, the LTM can simulate riverine transport and decay processes within the accuracy required by most water quality studies. The LTM is applicable to steady or unsteady one-dimensional unidirectional flows in fixed channels with tributary and lateral inflows. Application of the LTM is relatively simple and optional capabilities improve the model 's convenience. Appendices give file formats and three example LTM applications that include the incorporation of the QUAL II water quality model 's reaction kinetics into the LTM. (Author 's abstract)

Schoellhamer, D.H.; Jobson, H.E.

1986-01-01

262

Numerical method of characteristics for one-dimensional blood flow  

E-print Network

Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally intensive methods like finite elements and discontinuous Galerkin, while some recent applications require more efficient approaches (e.g. for real-time clinical decision support, phenomena occurring over multiple cardiac cycles, iterative solutions to optimization/inverse problems, and uncertainty quantification). Further, the high speed of pressure waves in blood vessels greatly restricts the time-step needed for stability in explicit schemes. We address both cost and stability by presenting an efficient and unconditionally stable method for approximating solutions to diagonal nonlinear hyperbolic systems. Theoretical analysis of the algorithm is given along with a comparison of our method to a discontinuous Galerkin implementation. Lastly, we demonstrate the ...

Acosta, Sebastian; Riviere, Beatrice; Penny, Daniel J; Rusin, Craig G

2014-01-01

263

One-dimensional photonic crystal fishbone hybrid nanocavity with nanoposts  

SciTech Connect

We propose and investigate a one-dimensional photonic crystal (PhC) fishbone (FB) hybrid nanocavity lying on silver substrate with a horizontal air slot. With very few PhC periods, the confined transverse-magnetic, TM{sub 10} hybrid mode concentrated within the air slot shows high quality factor over effective mode volume ratio larger than 10{sup 5}?{sup ?3}. Most importantly, this FB hybrid nanocavity allows formation of low-index nanoposts within the air slot without significantly affecting the mode properties. These nanoposts guarantee the structural stabilities under different environmental perturbations. Furthermore, capabilities of our proposed design in serving as optical sensors and tweezers for bio-sized nanoparticles are also investigated.

Lu, Tsan-Wen; Lin, Pin-Tso; Lee, Po-Tsung, E-mail: potsung@mail.nctu.edu.tw [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Rm. 413 CPT Building, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan (China)

2014-05-12

264

Transport through quasi-one-dimensional wires with correlated disorder.  

PubMed

We study transport properties of bulk-disordered quasi-one-dimensional (Q1D) wires paying main attention to the role of long-range correlations embedded into the disorder. First, we show that for stratified disorder for which the disorder is the same for all individual chains forming the Q1D wire, the transport properties can be analytically described provided the disorder is weak. When the disorder in every chain is not the same, however it has the same binary correlator, the general theory is absent. Thus, we consider the case when only one channel is open and all others are closed. For this situation we suggest a semianalytical approach which is quite effective for the description of the total transmission coefficient. Our numerical data confirm the validity of this approach. PMID:25375446

Herrera-González, I F; Méndez-Bermúdez, J A; Izrailev, F M

2014-10-01

265

One-dimensional relativistic dynamics with scaling formalism  

NASA Astrophysics Data System (ADS)

In one dimension, we investigate dynamics using special relativity only, but make no statement regarding any particular insight into the nature of the spacetime continuum. Indeed, we do away completely with any kind of formal tensor algebra or differential topology, but do incorporate scaling into our calculations. The purpose here is primarily pedagogical, as an extension to the standard undergraduate treatment of special relativity, but it is also a calculational tool, to be able to determine the motion of objects in a one-dimensional case even with accelerations and forces, without having to use the full general relativistic treatment. To illustrate this, we directly compare relativistic to Newtonian or non-relativistic motions for particularly instructive selected systems.

Asadi-Zeydabadi, Masoud; Sadun, Alberto C.

2013-01-01

266

Experiment and simulation on one-dimensional plasma photonic crystals  

SciTech Connect

The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5?Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range.

Zhang, Lin; Ouyang, Ji-Ting, E-mail: jtouyang@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

2014-10-15

267

Slow-light transmission in one-dimensional periodic structures  

SciTech Connect

We have analyzed the transmission properties of pulses through one-dimensional periodic structures in order to systematically explore the best conditions to achieve the maximum delay with the minimum possible distortion. In the absence of absorption and no layer variation, the transmission coefficient t{sub N} can be well approximated by a sum of Lorentzian resonances. The ratio between their width {Gamma}{sub r} and their separation {Delta}{omega}{sub r} is a crucial parameter to characterize the distortion of the transmitted pulse. For typical values of the parameters used in telecommunications and high index of refraction contrasts n{sub 2}/n{sub 1}, the distortion of the transmitted pulse is unacceptably large for frequencies near the edge of the transmission window. We estimate fractional delays achievables in terms of the central frequency used and the pulse bandwidth.

Barco, O. del; Ortuno, M. [Departamento de Fisica-CIOyN, Universidad de Murcia (Spain)

2010-02-15

268

ICARUS: A general one-dimensional heat conduction code  

NASA Astrophysics Data System (ADS)

A computer code for calculating one dimensional planar, cylindrical or spherical conduction heat transfer is described. The model can account for material phase change (solidification or melting, multiple material regions, temperature dependent material properties and time or temperature dependent boundary conditions. Finite difference techniques are used to discretize the differential equations. The resulting system of tri-diagonal equations are solved using a standard tri-diagonal reduction method. The equations are formulated so that the solution can be fully implicit, fully explicit or a user specified degree of mix. Six sample problems that compare numerical predictions to analytical solutions are discussed. Operation of the computer code and all input variables are described. Input file listings and typical edits for the six sample problems are given.

Sutton, S. B.

1984-07-01

269

One-dimensional plasma photonic crystals with sinusoidal densities  

SciTech Connect

Properties of electromagnetic waves with normal and oblique incidence have been studied for one-dimensional plasma layers with sinusoidal densities. Wave transmittance as a function of wave frequency exhibits photonic band gaps characteristic of photonic crystals. For periodic structures, increasing collision frequency is demonstrated to lead to greater absorption, increasing the modulation factor enlarges the gap width, and increasing incidence angle can change the gap locations of the two polarizations. If a defect layer is introduced by inserting a new plasma layer in the center, a defect mode may appear within the gap. Periodic number, collision frequency, and modulation factor can affect magnitude of the defect mode. The incidence angle enables the frequency to be tuned. Defect layer thickness affects both frequency and number of defect modes. These results may provide theoretical guidance in designing tunable narrow-band filters.

Qi, L., E-mail: qilimei1204@163.com; Shang, L.; Zhang, S. [College of Physics and Engineering, Qufu Normal University, No. 57, West Jingxuan Road, Qufu 273165 (China)] [College of Physics and Engineering, Qufu Normal University, No. 57, West Jingxuan Road, Qufu 273165 (China)

2014-01-15

270

One-dimensional vertical dust strings in a glass box  

SciTech Connect

The oscillation spectrum of a one-dimensional vertical dust string formed inside a glass box on top of the lower electrode in a gaseous electronics conference (GEC) reference cell was studied. A mechanism for creating a single vertical dust string is described. It is shown that the oscillation amplitudes, resonance frequencies, damping coefficients, and oscillation phases of the dust particles separate into two distinct groups. One group exhibits low damping coefficients, increasing amplitudes, and decreasing resonance frequencies for dust particles closer to the lower electrode. The other group shows high damping coefficients but anomalous resonance frequencies and amplitudes. At low oscillation frequencies, the two groups are also separated by a {pi} phase difference. One possible cause for the difference in behavior between the two groups is discussed.

Kong, Jie; Hyde, Truell W.; Matthews, Lorin; Qiao Ke; Zhang Zhuanhao; Douglass, Angela [Center for Astrophysics, Space Physics, and Engineering Research (CASPER) Baylor University Waco, Texas 76798-7310 (United States)

2011-07-15

271

Solution of a one-dimensional ablation model  

NASA Astrophysics Data System (ADS)

Ablation in multilayered one-dimensional media is studied. A finite element technique using a Streamline Upwind/Petrov-Galerkin (SU/PG) formulation is employed with a moving mesh which adapts itself to the moving boundary at each time step. The SU/PG formulation is used to avoid oscillations caused by first order derivatives in the energy equation. Ablation problems with time-dependent heat fluxes and a typical example in aerospace thermal protection applications are solved. Critical comparisons are made with finite differences results recently obtained through the control volume approach with exponential differencing. The generalized integral transform technique (GITT) is used as an alternative solution to ablation in multilayered media and to validate the results obtained by the finite element method. The eigenvalues needed in the GITT solution are determined simultaneously with the tansformed temperatures by rewriting the associated transcedental equations into ordinary differential equations.

Rupertijunior, Nerbe Jose

1991-11-01

272

Growth of One-Dimensional MnO2 Nanostructure  

NASA Astrophysics Data System (ADS)

Large scale MnO2 nanorods were controllably synthesized from the inexpensive precursors (e.g., manganese acetate, ammonium persulfate) via a facile one-step low temperature hydrothermal strategy. The crystal phase and microscopic morphology of the as-prepared MnO2 nanorods were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). Through investigating the morphology evolution of MnO2 products in the whole synthesis process, a novel growth mechanism of these MnO2 nanorods was proposed, which may be efficiently extended to other material systems as a general approach towards one-dimensional nanostructures. The obtained MnO2 nanorods may have potential applications in Li-ion batteries and supercapacitors.

Lu, Pai; Xue, Dongfeng

273

Negative refraction in one-dimensional photonic crystals  

NASA Astrophysics Data System (ADS)

Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here, we discuss recent theoretical and simulation results that showed that negative refraction could be present near the low frequency edge of at least the second, fourth and sixth bandgaps of a lossless one-dimensional photonic crystals (1DPC) structure. That is, negative refraction is a multiband phenomenon. We also discuss the negative refraction correctness condition that gives the angular region where negative refraction occurs. We compare two current negative refraction theoretical models with recent experimental results. In order to succeed, an output refraction correction is utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theoretical models in the negative refraction zone.

Lugo, J. E.; Doti, Rafael; Faubert, J.

2012-10-01

274

Luttinger-liquid behavior of one-dimensional 3He  

NASA Astrophysics Data System (ADS)

The ground-state properties of one-dimensional 3He are studied using quantum Monte Carlo methods. The equation of state is calculated in a wide range of physically relevant densities and is well interpolated by a power-series fit. The Luttinger liquid theory is found to describe the long-range properties of the correlation functions. The density dependence of the Luttinger parameter is explicitly found, and interestingly it shows a nonmonotonic behavior. Depending on the density, the static structure factor can be a smooth function of the momentum or might contain a peak of a finite or infinite height. Although no phase transitions are present in the system, we identify a number of physically different regimes, including an ideal Fermi gas, a "Bose gas." a "super-Tonks-Girardeau" regime, and a "quasicrystal." The obtained results are applicable to unpolarized, partially, or fully polarized 3He.

Astrakharchik, G. E.; Boronat, J.

2014-12-01

275

Quasi one dimensional transport in individual electrospun composite nanofibers  

SciTech Connect

We present results of transport measurements of individual suspended electrospun nanofibers Poly(methyl methacrylate)-multiwalled carbon nanotubes. The nanofiber is comprised of highly aligned consecutive multiwalled carbon nanotubes. We have confirmed that at the range temperature from room temperature down to ?60 K, the conductance behaves as power-law of temperature with an exponent of ? ? 2.9?10.2. The current also behaves as power law of voltage with an exponent of ? ? 2.3?8.6. The power-law behavior is a footprint for one dimensional transport. The possible models of this confined system are discussed. Using the model of Luttinger liquid states in series, we calculated the exponent for tunneling into the bulk of a single multiwalled carbon nanotube ?{sub bulk} ? 0.06 which agrees with theoretical predictions.

Avnon, A., E-mail: avnon@phys.fu-berlin.de; Datsyuk, V.; Trotsenko, S. [Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)] [Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Wang, B.; Zhou, S. [Research Center of Microperipheric Technologies, Technische Universität Berlin, TiB4/2-1, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)] [Research Center of Microperipheric Technologies, Technische Universität Berlin, TiB4/2-1, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Grabbert, N.; Ngo, H.-D. [Microsystem Engineering (FB I), University of Applied Sciences, Wilhelminenhofstr. 74 (C 525), 12459 Berlin (Germany)] [Microsystem Engineering (FB I), University of Applied Sciences, Wilhelminenhofstr. 74 (C 525), 12459 Berlin (Germany)

2014-01-15

276

Stepwise nanopore evolution in one-dimensional nanostructures.  

PubMed

We report that established simple lithium (Li) ion battery cycles can be used to produce nanopores inside various useful one-dimensional (1D) nanostructures such as zinc oxide, silicon, and silver nanowires. Moreover, porosities of these 1D nanomaterials can be controlled in a stepwise manner by the number of Li-battery cycles. Subsequent pore characterization at the end of each cycle allows us to obtain detailed snapshots of the distinct pore evolution properties in each material due to their different atomic diffusion rates and types of chemical bonds. Also, this stepwise characterization led us to the first observation of pore size increases during cycling, which can be interpreted as a similar phenomenon to Ostwald ripening in analogous nanoparticle cases. Finally, we take advantage of the unique combination of nanoporosity and 1D materials and demonstrate nanoporous silicon nanowires (poSiNWs) as excellent supercapacitor (SC) electrodes in high power operations compared to existing devices with activated carbon. PMID:20334444

Choi, Jang Wook; McDonough, James; Jeong, Sangmoo; Yoo, Jee Soo; Chan, Candace K; Cui, Yi

2010-04-14

277

Experiment and simulation on one-dimensional plasma photonic crystals  

NASA Astrophysics Data System (ADS)

The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5 Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range.

Zhang, Lin; Ouyang, Ji-Ting

2014-10-01

278

Laughlin wave function and one-dimensional free fermions  

SciTech Connect

Making use of the well-known phase-space reduction in the lowest Landau level, we show that the Laughlin wave function for the {nu}=1/{ital m} case can be obtained exactly as a coherent-state representation of a one-dimensional (1D) wave function. The 1D system consists of {ital m} copies of free fermions associated with each of the {ital N} electrons, confined in a common harmonic well potential. Interestingly, the condition for this exact correspondence is found to incorporate Jain`s parton picture. We argue that this correspondence between the free fermions and quantum Hall effect is due to the mapping of the 1D system under consideration to the Gaussian unitary ensemble in the random matrix theory.

Panigrahi, P.K.; Sivakumar, M. [School of Physics, University of Hyderabad, Hyderabad-500 134 (India)] [School of Physics, University of Hyderabad, Hyderabad-500 134 (India)

1995-11-15

279

One-dimensional cloud fluid model for propagating star formation  

NASA Technical Reports Server (NTRS)

The aim of this project was to study the propagation of star formation (SF) with a self-consistent deterministic model for the interstellar gas. The questions of under what conditions does star formation propagate in this model and what are the mechanisms of the propagation are explored. Here, researchers used the deterministic Oort-type cloud fluid model of Scalo and Struck-Marcell (1984, also see the review of Struck-Marcell, Scalo and Appleton 1987). This cloud fluid approach includes simple models for the effects of cloud collisional coalescence or disruption, collisional energy dissipation, and cloud disruption and acceleration as the result of young star winds, HII regions and supernovae. An extensive one-zone parameter study is presented in Struck-Marcell and Scalo (1987). To answer the questions above, researchers carried out one-dimensional calculations for an annulus within a galactic disk, like the so-called solar neighborhood of the galactic chemical evolution. In the calculations the left-hand boundary is set equal to the right hand boundary. The calculation is obviously idealized; however, it is computationally convenient to study the first order effects of propagating star formation. The annulus was treated as if it were at rest, i.e., in the local rotating frame. This assumption may remove some interesting effects of a supersonic gas flow, but was necessary to maintain a numerical stability in the annulus. The results on the one-dimensional propagation of SF in the Oort cloud fluid model follow: (1) SF is propagated by means of hydrodynamic waves, which can be generated by external forces or by the pressure generated by local bursts. SF is not effectively propagated via diffusion or variation in cloud interaction rates without corresponding density and velocity changes. (2) The propagation and long-range effects of SF depend on how close the gas density is to the critical threshold value, i.e., on the susceptibility of the medium.

Titus, Timothy N.; Struck-Marcell, Curtis

1990-01-01

280

A One-Dimensional Synthetic-Aperture Microwave Radiometer  

NASA Technical Reports Server (NTRS)

A proposed one-dimensional synthetic- aperture microwave radiometer could serve as an alternative to either the two-dimensional synthetic-aperture radiometer described in the immediately preceding article or to a prior one-dimensional one, denoted the Electrically Scanned Thinned Array Radiometer (ESTAR), mentioned in that article. The proposed radiometer would operate in a pushbroom imaging mode, utilizing (1) interferometric cross-track scanning to obtain cross-track resolution and (2) the focusing property of a reflector for along-track resolution. The most novel aspect of the proposed system would be the antenna (see figure), which would include a cylindrical reflector of offset parabolic cross section. The reflector could be made of a lightweight, flexible material amenable to stowage and deployment. Other than a stowage/deployment mechanism, the antenna would not include moving parts, and cross-track scanning would not entail mechanical rotation of the antenna. During operation, the focal line, parallel to the cylindrical axis, would be oriented in the cross-track direction, so that placement of receiving/radiating elements at the focal line would afford the desired along-track resolution. The elements would be microwave feed horns sparsely arrayed along the focal line. The feed horns would be oriented with their short and long cross-sectional dimensions parallel and perpendicular, respectively, to the cylindrical axis to obtain fan-shaped beams having their broad and narrow cross-sectional dimensions parallel and perpendicular, respectively, to the cylindrical axis. The interference among the beams would be controlled in the same manner as in the ESTAR to obtain along-cylindrical- axis (cross-track) resolution and cross-track scanning.

Doiron, Terence; Piepmeier, Jeffrey

2010-01-01

281

Lanthanide coordination polymers based on multi-donor ligand containing pyridine and phthalate moieties: Structures, luminescence and magnetic properties  

SciTech Connect

A new family of five lanthanide-organic coordination polymers incorporating multi-functional N-hetrocyclic dicarboxylate ligand, namely, [Ln{sub 2}(Hdpp){sub 2}(dpp){sub 2}]{sub n}Ln=Pr(1), Eu(2), Gd(3), Dy(4), Er(5) (H{sub 2}dpp=1-(3, 4-dicarboxyphenyl) pyridin-4-ol) have been fabricated successfully through solvothermal reaction of 1-(3,4-dicarboxyphenyl)-4-hydroxypyridin-1-ium chloride with trivalent lanthanide salts, and have been characterized systematically. The complexes 1–5 are isomorphous and isostructural. They all feature three dimensional (3D) frameworks based on the interconnection of 1D double chains composed of the binuclear moiety [Ln{sub 2}(Hdpp){sub 2}]{sup 4+} basic carboxylate as secondary building unit (SBU). The results of magnetic analysis shows the same bridging fashion of carboxylic group in this case results in the different magnetic properties occurring within lanthanide polymers. Moreover, the Eu(III) and Dy(III) complexes display characteristic luminescence emission in the visible regions. - Graphical abstract: A new family of lanthanide-organic frameworks incorporating multi-donor twisted ligand has been fabricated successfully, and has been characterized systematically. The complexes 1–5 are isostructural, and all feather three dimensional (3D) frameworks based on the interconnection of 1D double stride chains composed of the binuclear moiety [Ln{sub 2}(Hdpp){sub 2}]{sup 2+} basic carboxylate as secondary building unit (SBU). Display Omitted - Highlights: • New family of lanthanide–organic coordination polymers incorporating multifunctional N-hetrocyclic dicarboxylate ligand has been fabricated. • They have been characterized systematically. • They all feather three dimensional frameworks based on the binuclear moiety of [Ln{sub 2}(Hdpp){sub 2}]{sup 2+}. • The Eu(III) and Dy(III) analogues exhibit intense photoluminescence.

Feng, Xun [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Liu, Lang [College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002 (China); College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Wang, Li-Ya, E-mail: wlya@lynu.edu.cn [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang 473601 (China); Song, Hong-Liang; Qiang Shi, Zhi; Wu, Xu-Hong [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Ng, Seik-Weng [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 80203 (Saudi Arabia)

2013-10-15

282

Copper(II)-lanthanide(III) coordination polymers constructed from pyridine-2,5-dicarboxylic acid: Preparation, crystal structure and photoluminescence  

SciTech Connect

A series of 3d-4f heterometallic coordination polymers, formulated as {l_brace} [Cu{sub 3}Ln{sub 2}(pydc){sub 6}(H{sub 2}O){sub 12}]{center_dot}4H{sub 2}O{r_brace} {sub n} [Ln=Tb (1), Eu (2), Dy (3), Ho (4), Lu (5)], {l_brace} [CuNd{sub 2}(pydc){sub 4}(H{sub 2}O){sub 3}]{center_dot}H{sub 2}O{r_brace} {sub n} (6) and {l_brace} [Cu{sub 3}Pr{sub 2}(pydc){sub 6}(H{sub 2}O){sub 13}]{center_dot}4H{sub 2}O{r_brace} {sub n} (7) (where H{sub 2}pydc=pyridine-2,5-dicarboxylic acid), have been hydrothermally prepared by reactions of H{sub 2}pydc ligand with lanthanide ions in the presence of Cu(II) ion. X-ray crystal structure analysis reveals that these compounds exhibit rich structural chemistry. 1-5 are isomorphous and present a two-dimensional network constructed from Ln{sub 2}Cu{sub 2}L{sub 2}(H{sub 2}O){sub 2} SBU rings and CuL{sub 2}(H{sub 2}O) building blocks. In 6, two-dimensional ladder-like layers based on Nd(III) belts and CuL{sub 2}O{sub 2} units are assembled by H{sub 2}pydc ligands into a three-dimensional open framework. Polymer 7 displays a two-dimensional wave-like layer structure containing two distinct ring units, in which a new coordination mode of the pydc{sup 2-} ligand is observed. The results indicate that the coordination flexibility of the pydc{sup 2-} ligand and lanthanide contraction effect play cooperative roles in the formation of coordination polymers with different polymeric architectures. Compounds 1-2 exhibit intense green and red luminescence emission characteristics of Tb(III) and Eu(III), respectively. Furthermore, elemental analyses (EA), infrared spectra (IR) and thermogravimetric analyses (TGA) of these compounds were also studied. - Graphical abstract: Seven 3d-4f heterometallic coordination polymers were synthesized by reactions of H{sub 2}pydc with lanthanide metal ions in the presence of Cu{sup 2+}, the effects of Cu{sup 2+} on the structures and photoluminescent properties of Ln-pydc{sup 2-} systems were investigated. Highlights: Black-Right-Pointing-Pointer Seven 3d-4f heterometallic compounds have been prepared and characterized. Black-Right-Pointing-Pointer 1-5 and 7 are constructed from Ln{sub 2}Cu{sub 2}L{sub 2}(H{sub 2}O){sub 2} rings and CuL{sub 2}(H{sub 2}O) building blocks. Black-Right-Pointing-Pointer One new coordination mode of the pydc{sup 2-} ligand is first observed. Black-Right-Pointing-Pointer 1-2 exhibit intense characteristic luminescence emission spectra of lanthanide ions.

Xia Zhengqiang; Wei Qing [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China); Chen Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China); Feng Xinming; Xie Gang [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China); Qiao Chengfang [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China); Department of Chemistry and Chemical Engineering, Shangluo University, Shangluo 726000 (China); Zhang Guochun [Department of Chemistry and Chemical Engineering, Shangluo University, Shangluo 726000 (China); Gao Shengli [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069 (China)

2013-01-15

283

Modular, homochiral, porous coordination polymers: rational design, enantioselective guest exchange sorption and ab initio calculations of host-guest interactions.  

PubMed

Two new, homochiral, porous metal-organic coordination polymers [Zn(2)(ndc){(R)-man}(dmf)]?3DMF and [Zn(2)(bpdc){(R)-man}(dmf)]?2DMF (ndc=2,6-naphthalenedicarboxylate; bpdc=4,4'-biphenyldicarboxylate; man=mandelate; dmf=N,N'-dimethylformamide) have been synthesized by heating Zn(II) nitrate, H(2)ndc or H(2)bpdc and chiral (R)-mandelic acid (H(2)man) in DMF. The colorless crystals were obtained and their structures were established by single-crystal X-ray diffraction. These isoreticular structures share the same topological features as the previously reported zinc(II) terephthalate lactate [Zn(2)(bdc){(S)-lac}(dmf)]?DMF framework, but have larger pores and opposite absolute configuration of the chiral centers. The enhanced pores size results in differing stereoselective sorption properties: the new metal-organic frameworks effectively and stereoselectively (ee up to 62?%) accommodate bulkier guest molecules (alkyl aryl sulfoxides) than the parent [Zn(2)(bdc){(S)-lac}(dmf)]?DMF, while the latter demonstrates decent enantioselectivity toward precursor of chiral anticancer drug sulforaphane, CH(3)SO(CH(2))(4)OH. The new homochiral porous metal-organic coordination polymers are capable of catalyzing a highly selective oxidation of bulkier sulfides (2-NaphSMe (2-C(10)H(7)SMe) and PhSCH(2)Ph) that could not be achieved by the smaller-pore [Zn(2)(bdc){(S)-lac}(dmf)]?DMF. The sorption of different guest molecules (both R and S isomers) into the chiral pores of [Zn(2)(bdc){(S)-lac}(dmf)]?DMF was modeled by using ab initio calculations that provided a qualitative explanation for the observed sorption enantioselectivity. The high stereo-preference is accounted for by the presence of coordinated inner-pore DMF molecule that forms a weak C-H...O bond between the DMF methyl group and the (S)-PhSOCH(3) sulfinyl group. PMID:20730747

Dybtsev, Danil N; Yutkin, Maxim P; Samsonenko, Denis G; Fedin, Vladimir P; Nuzhdin, Alexey L; Bezrukov, Andrey A; Bryliakov, Konstantin P; Talsi, Evgeniy P; Belosludov, Rodion V; Mizuseki, Hiroshi; Kawazoe, Yoshiyuki; Subbotin, Oleg S; Belosludov, Vladimir R

2010-09-10

284

A pillared-layer coordination polymer with a rotatable pillar acting as a molecular gate for guest molecules.  

PubMed

The design of pore properties utilizing flexible motifs and functional groups is of importance to obtain porous coordination polymers with desirable functions. We have prepared a 3D pillared-layer coordination polymer, {[Cd(2)(pzdc)(2)L(H(2)O)(2)].5(H(2)O).(CH(3)CH(2)OH)}(n) (1, H(2)pzdc = 2,3-pyrazinedicarboxylic acid; L = 2,5-bis(2-hydroxyethoxy)-1,4-bis(4-pyridyl)benzene) showing (i) a rotatable pillar bearing ethylene glycol side chains acting as a molecular gate with locking/unlocking interactions triggered by guest inclusion between the side chains, (ii) framework flexibility with slippage of the layers, and (iii) coordinatively unsaturated metal centers as guest accessible sites through the removal of the water coligands. The framework clearly shows reversible single-crystal-to-single-crystal transformations in response to the removal and rebinding of guest molecules, the observation of these processes has provided fundamental clues to the understanding of the sorption profiles. The X-ray structures indicate that the 3D host framework is retained during the transformations, involving mainly rotation of the pillars and slippage of the layers. The structure of dried form 2, [Cd(2)(pzdc)(2)L](n), has no void volume and no water coligands. Interestingly, the adsorption isotherm of water for 2 at 298 K exhibits three distinct steps coinciding with the framework functions. Compound 2 favors the uptake of CO(2) (195 K) over N(2) (77 K) and O(2) (77 K). Above all, we report on a molecular gate with a rotational module exhibiting a locking/unlocking system which accounts for gate-opening type sorption profiles. PMID:19681608

Seo, Joobeom; Matsuda, Ryotaro; Sakamoto, Hirotoshi; Bonneau, Charlotte; Kitagawa, Susumu

2009-09-01

285

Ag(I) and Zn(II) coordination polymers with a bulky naphthalene-based dicarboxyl tecton and different 4,4'-bipyridyl-like bridging co-ligands: structural regulation and properties.  

PubMed

A series of six Ag(I) and Zn(II) coordination polymers, namely, [Ag(2)(ndc)](?) (1), {[Zn(ndc)(H(2)O)](H(2)O)}(?) (2), {[Ag(2)(ndc)(4bpy)(2)][Ag(4bpy)(H(2)O)](ClO(4))(H(2)O)(2)}(?) (3), [Zn(5)(ndc)(4)(4bpy)(2)(?(3)-OH)(2)](?) (4), {[Ag(ndc)(abp)][Ag(abp)](H(2)O)(3)}(?) (5), and {[Zn(2)(ndc)(2)(abp)(H(2)O)(2)](H(2)O)(2)}(?) (6), have been prepared by using 2,3-naphthalenedicarboxylic acid (H(2)ndc), an analogue of 1,2-benzenedicarboxylic acid (H(2)bdc), and different 4,4'-bipyridyl-like bridging co-ligands 4,4'-bipyridine (4bpy) and trans-4,4'-azobis(pyridine) (abp). The initial complexes 1 and 2 display the unusual two-dimensional (2-D) five-connected (4(8).6(2)) and the 2-D three-connected (4.8(2)) coordination networks, respectively. When two comparable rod-like linkers 4bpy and abp (with different N,N'-donor separations of the molecular backbones of ca. 7 and 9 Å) are further introduced, two one-dimensional (1-D) complexes 3 and 5, a three-dimensional (3-D) coordination framework 4 with (4(3))(4(3).6(3))(4(3).6(5).8(2))(4(4).6(4).8(2))(4(10).6(5)) topology and a 2-D 6(3) layered coordination polymer 6 are constructed. A structural comparison of these complexes with those based on the structurally related bdc ligand suggests that the extended ?-conjugated system of ndc with different electronic nature and steric bulk play an important role in constructing the supramolecular architectures for 1-6, which are also regulated by different bridging N-donor co-ligands and metal ions. Moreover, complexes 1-6 show strong solid-state luminescence emissions at room temperature that mainly originate from the intraligand transitions of ndc. PMID:21431216

Fang, Shao-Ming; Hu, Min; Zhang, Qiang; Du, Miao; Liu, Chun-Sen

2011-05-01

286

The use of contact transformations of the inhomogeneous Monge-Ampere equation in one-dimensional gas dynamics  

NASA Astrophysics Data System (ADS)

An approach to solving equations of one-dimensional gas dynamics is proposed which provides an alternative to the use of Euler and Lagrange coordinates. The approach uses Martin's substitution, which leads to the inhomogeneous Monger-Ampere equation. In this case, there are equations of state for which the contact symmetries of the equation form an infinite pseudogroup. The approach makes it possible to obtain solutions that are dependent on arbitrary functions and to write an infinite number of new conservation laws.

Khabirov, S. V.

287

Two Ag(I) coordination polymers derived from melamine and dicarboxylates: Syntheses, crystal structures and thermal stabilities  

NASA Astrophysics Data System (ADS)

Two mixed-ligand Ag(I) coordination polymers (CPs), [(NH 4)Ag 3(MA) 2(suc) 2] n ( 1), [Ag 2(MA) 2(adip)·CH 3OH·H 2O] n ( 2), (where MA = melamine, H 2suc = succinic acid, H 2adip = adipic acid) have been synthesized and structurally characterized by element analysis, IR and X-ray single-crystal diffraction. The CP 1 is a three-dimensional (3D) framework in which the MA acts as a tridentate ligand and suc 2- anion shows three types of coordination modes. Each Ag(I) ion acts as a 4-connected node to generate three- and six-membered cycles, as a result, the network can be simplified to be an overall multi-layered Kagomé topology. The CP 2 is a 2D single-layer structure constructed by tridentate MA ligands and adip 2- anions. The adjacent single-layers are inter-linked to form a double-layer 2D structure through the Ag⋯Ag interactions. Two CPs structurally vary from 2D sheet to 3D framework, which indicates that the different dicarboxylates and coordination modes of MA ligand have significant influence on the final structures. Moreover, the thermal stabilities of them were also discussed.

Li, Yun-Hua; Sun, Di; Luo, Geng-Geng; Liu, Fu-Jing; Hao, Hong-Jun; Wen, Yi-Mei; Zhao, Yang; Huang, Rong-Bin; Zheng, Lan-Sun

2011-08-01

288

Studies of the structural and magnetic properties of an unsymmetrical ligand 1,2,4-benzenetricarboxylic acid based chiral 3-D trinickel coordination polymer as an alkali base-influenced hydrothermal reaction product  

NASA Astrophysics Data System (ADS)

The reaction of 1,2,4-benzenetricarboxylic acid (H3btc), as a ligand, under pH-controlled hydrothermal conditions with nickel salts leads to the formation of a coordination polymer of {CsNi3(OH)(H2O)3[C6H3(CO2)3]2·3H2O}n (1). The subunit of compound 1 contains a hydroxide- and carboxylate-bridged trinickel clusters that are linked by an unsymmetrical organic carboxylate spacer to form a chiral three-dimensional anionic framework, in which cesium cations and guest water molecules are located in one-dimensional channels. The presence of a hydroxide ion serves both as a deprotonation agent and a cation source during the hydrothermal reaction, thus permitting the extent of deprotonation of the unsymmetrical ligand H3btc to be controlled, which is essential for the successful formation of compound 1. The magnetic properties of compound 1 were analyzed. Both dc and ac magnetic susceptibility as well as reduced magnetization measurements confirmed the spin-frustration nature of 1.

Peng, Yi-Ru; Chien, Po-Hsiu; Chung, Huey-Ting; Pan, Pei-Yun; Liu, Yen-Hsiang; Yang, En-Che

2014-04-01

289

Polymer translocation through a nanopore - a showcase of anomalous diffusion  

E-print Network

The translocation dynamics of a polymer chain through a nanopore in the absence of an external driving force is analyzed by means of scaling arguments, fractional calculus, and computer simulations. The problem at hand is mapped on a one dimensional {\\em anomalous} diffusion process in terms of reaction coordinate $s$ (i.e. the translocated number of segments at time $t$) and shown to be governed by an universal exponent $\\alpha = 2/(2\

J. L. A. Dubbeldam; A. Milchev; V. G. Rostiashvili; T. A. Vilgis

2007-01-26

290

Hydrothermal synthesis, crystal structure, and catalytic potential of a one-dimensional molybdenum oxide/bipyridinedicarboxylate hybrid.  

PubMed

The reaction of MoO3, 2,2'-bipyridine-5,5-dicarboxylic acid (H2bpdc), water, and dimethylformamide in the mole ratio 1:1:1730:130 at 150 °C for 3 days in a rotating Teflon-lined digestion bomb leads to the isolation of the molybdenum oxide/bipyridinedicarboxylate hybrid material (DMA)[MoO3(Hbpdc)]·nH2O (1) (DMA = dimethylammonium). Compound 1 was characterized by scanning electron microscopy, FT-IR and (13)C{(1)H} CP MAS NMR spectroscopies, and elemental and thermogravimetric analyses. The solid state structure of 1 was solved and refined through Rietveld analysis of high resolution synchrotron X-ray powder diffraction data in conjunction with information derived from the above techniques. The material, crystallizing in the noncentrosymmetric monoclinic space group Pc, is composed of an anionic one-dimensional organic-inorganic hybrid polymer, ?(1)[MoO3(Hbpdc)](-), formed by corner-sharing distorted {MoO4N2} octahedra, which cocrystallizes with charge-balancing DMA(+) cations and one water molecule per metal center. In the crystal structure of 1, the close packing of individual anionic polymers, DMA(+) cations, and water molecules is mediated by a series of supramolecular contacts, namely strong (O-H···O, N(+)-H···O(-)) and weak (C-H···O) hydrogen bonding interactions, and ?-? contacts involving adjacent coordinated Hbpdc(-) ligands. The catalytic potential of 1 was investigated in the epoxidation reactions of the bioderived olefins methyl oleate (Ole) and DL-limonene (Lim) using tert-butylhydroperoxide (TBHP) as the oxygen donor and 1,2-dichloroethane (DCE) or (trifluoromethyl)benzene (BTF) as cosolvent, at 55 or 75 °C. Under these conditions, 1 acts as a source of active soluble species, leading to epoxide yields of up to 98% for methyl 9,10-epoxystearate (BTF, 75 °C, 100% conversion of Ole) and 89% for 1,2-epoxy-p-menth-8-ene (DCE, 55 °C, 95% conversion of Lim). Catalytic systems employing the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as solvent could be effectively recycled. PMID:23531277

Amarante, Tatiana R; Neves, Patrícia; Valente, Anabela A; Paz, Filipe A Almeida; Fitch, Andrew N; Pillinger, Martyn; Gonçalves, Isabel S

2013-04-15

291

A string reaction coordinate for the folding of a polymer chain  

E-print Network

We investigate the crystallization mechanism of a single, flexible homopolymer chain with short range attractions. For a sufficiently narrow attractive well, the system undergoes a first-order like freezing transition from an expanded disordered coil to a compact crystalline state. Based on a maximum likelihood analysis of committor values computed for configurations obtained by Wang-Landau sampling, we construct a non-linear string reaction coordinate for the coil-to-crystal transition. In contrast to a linear reaction coordinate, the string reaction coordinate captures the effect of different degrees of freedom controlling different stages of the transition. Our analysis indicates that a combination of the energy and the global crystallinity parameter Q6 provide the most accurate measure for the progress of the transition. While the crystallinity parameter Q6 is most relevant in the initial stages of the crystallization, the later stages are dominated by a decrease in the potential energy.

Christian Leitold; Wolfgang Lechner; Christoph Dellago

2015-01-16

292

A string reaction coordinate for the folding of a polymer chain  

E-print Network

We investigate the crystallization mechanism of a single, flexible homopolymer chain with short range attractions. For a sufficiently narrow attractive well, the system undergoes a first-order like freezing transition from an expanded disordered coil to a compact crystalline state. Based on a maximum likelihood analysis of committor values computed for configurations obtained by Wang-Landau sampling, we construct a non-linear string reaction coordinate for the coil-to-crystal transition. In contrast to a linear reaction coordinate, the string reaction coordinate captures the effect of different degrees of freedom controlling different stages of the transition. Our analysis indicates that a combination of the energy and the global crystallinity parameter Q6 provide the most accurate measure for the progress of the transition. While the crystallinity parameter Q6 is most relevant in the initial stages of the crystallization, the later stages are dominated by a decrease in the potential energy.

Leitold, Christian; Dellago, Christoph

2015-01-01

293

An adaptive grid algorithm for one-dimensional nonlinear equations  

NASA Technical Reports Server (NTRS)

Richards' equation, which models the flow of liquid through unsaturated porous media, is highly nonlinear and difficult to solve. Step gradients in the field variables require the use of fine grids and small time step sizes. The numerical instabilities caused by the nonlinearities often require the use of iterative methods such as Picard or Newton interation. These difficulties result in large CPU requirements in solving Richards equation. With this in mind, adaptive and multigrid methods are investigated for use with nonlinear equations such as Richards' equation. Attention is focused on one-dimensional transient problems. To investigate the use of multigrid and adaptive grid methods, a series of problems are studied. First, a multigrid program is developed and used to solve an ordinary differential equation, demonstrating the efficiency with which low and high frequency errors are smoothed out. The multigrid algorithm and an adaptive grid algorithm is used to solve one-dimensional transient partial differential equations, such as the diffusive and convective-diffusion equations. The performance of these programs are compared to that of the Gauss-Seidel and tridiagonal methods. The adaptive and multigrid schemes outperformed the Gauss-Seidel algorithm, but were not as fast as the tridiagonal method. The adaptive grid scheme solved the problems slightly faster than the multigrid method. To solve nonlinear problems, Picard iterations are introduced into the adaptive grid and tridiagonal methods. Burgers' equation is used as a test problem for the two algorithms. Both methods obtain solutions of comparable accuracy for similar time increments. For the Burgers' equation, the adaptive grid method finds the solution approximately three times faster than the tridiagonal method. Finally, both schemes are used to solve the water content formulation of the Richards' equation. For this problem, the adaptive grid method obtains a more accurate solution in fewer work units and less computation time than required by the tridiagonal method. The performance of the adaptive grid method tends to degrade as the solution process proceeds in time, but still remains faster than the tridiagonal scheme.

Gutierrez, William E.; Hills, Richard G.

1990-01-01

294

Linear Coordination Fullerene C60 Polymer [{Ni(Me3P)2}(?-?(2),?(2)-C60)]? Bridged by Zerovalent Nickel Atoms.  

PubMed

Coordination nickel-bridged fullerene polymer [{Ni(Me3P)2}(?-?(2),?(2)-C60)]? (1) has been obtained via reduction of a Ni(II)(Me3P)2Cl2 and C60 mixture. Each nickel atom is linked in the polymer with two fullerene units by ?(2)-type Ni-C(C60) bonds of 2.087(8)-2.149(8) Å length. Nickel atoms are coordinated to the 6-6 bonds of C60 as well as two trimethylphosphine ligands to form a four-coordinated environment around the metal centers. Fullerene cages approach very close to each other in the polymer with a 9.693(3) Å interfullerene center-to-center distance, and two short interfullerene C-C contacts of 2.923(7) Å length are formed. Polymer chains are densely packed in a crystal with interfullerene center-to-center distances between fullerenes from neighboring polymer chains of 9.933(3) Å and multiple interfullerene C···C contacts. As a result, three-dimensional dense fullerene packing is formed in 1. According to optical and electron paramagnetic resonance spectra, fullerenes are neutral in 1 and nickel atoms have a zerovalent state with a diamagnetic d(10) electron configuration. The density functional theory calculations prove the diamagnetic state of the polymer with a singlet-triplet gap wider than 1.37 eV. PMID:25369115

Konarev, Dmitri V; Khasanov, Salavat S; Nakano, Yoshiaki; Otsuka, Akihiro; Yamochi, Hideki; Saito, Gunzi; Lyubovskaya, Rimma N

2014-11-17

295

Synthesis, crystal structure and magnetic properties of the triply bridged one-dimensional polymers [ Cu 2( ClO 4)( OAc) 2( bppz)( H 2 O) 2]( ClO 4)( H 2 O) n and [ Cu 2( OBz) 3( bppz)]( ClO 4)( H 2 O) 2 n ; bppz=2,5-bis(2-pyridyl)pyrazine  

Microsoft Academic Search

Compounds [Cu2(ClO4)(OAc)2(bppz)(H2O)2](ClO4)(H2O)n (1) and [Cu2(OBz)3(bppz)](ClO4) (H2O)2n (2), where bppz is 2,5-bis(2-pyridyl)pyrazine. OAc acetate and OBz benzoate, have been synthesized and characterized crystallographically. Polymer 1 crystallized in the monoclinic system, space group P21\\/m, a=8.305(1), b=10.747(2), c=15.320(2) A?, ?=101.02(1)°, Z=2, R1 for 1837 observed reflections [1>2?(J)], measured at 213 K, was 0.0374. The structure consists of centrosymmetric dinuclear copper bppz units bridged

Antonia Neels; Helen Stoeckli-Evans; Albert Escuer; Ramon Vicente

1997-01-01

296

Gas adsorption/separation properties of metal directed self-assembly of two coordination polymers with 5-nitroisophthalate  

SciTech Connect

Two new coordination polymers, namely, [Co(µ-nip)(µ-bpe)]{sub n} (1) and [Zn(µ-nip)(µ-bpe)]{sub n} (2) (nip: 5-nitroisophthalate, bpe: 1,2-bis(4-pyridyl)ethane) were hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and thermal analysis. Moreover, atomically detailed simulation studies of complex 2 for CO{sub 2}/CH{sub 4} adsorption and separation were performed. Complex 1 consists of two dimensional (2D) (4,4) grid networks with the point symbol of 4{sup 4}.6{sup 2}. Complex 2 exhibits a 3-fold interpenetrating 3D framework with 6{sup 5}.8-dmp topology. Thermal properties of the complexes showed that both complexes were stable over 320 °C. Simulation studies demonstrated that complex 2 can separate CO{sub 2} from CH{sub 4} at low pressures at 273 K. - Graphical abstract: In this study, two new coordination polymers, namely, [Co(µ-nip)(µ-bpe)]{sub n} (1) and [Zn(µ-nip)(µ-bpe)]{sub n} (2) (nip: 5-nitroisophthalate, bpe: 1,2-bis(4-pyridyl)ethane) were hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and thermal analysis. Moreover, atomically detailed simulation studies of complex 2 for CO{sub 2}/CH{sub 4} adsorption and separation were performed. Complex 1 consists of two dimensional (2D) (4,4) grid networks with the point symbol of 4{sup 4}.6{sup 2}. Complex 2 exhibits a 3-fold interpenetrating 3D framework with 6{sup 5}.8-dmp topology. Simulation studies demonstrated that complex 2 can separate CO{sub 2} from CH{sub 4} at low pressures at 273 K. Display Omitted - Highlights: • Two new coordination polymers with 5-nitroisophthalate and 1,2-bis(4-pyridyl)ethane. • Atomically detailed simulation studies of the complexes. • Complex 2 can be proposed as molecular sieve to separate CO{sub 2} from CH{sub 4} at low pressures.

Ar?c?, Mürsel [Department of Chemistry, Faculty of Arts and Sciences, Eski?ehir Osmangazi University, 26480 Eski?ehir (Turkey); Ye?ilel, Okan Zafer, E-mail: yesilel@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eski?ehir Osmangazi University, 26480 Eski?ehir (Turkey); Keskin, Seda [Department of Chemical and Biological Engineering, Koç University, ?stanbul (Turkey); ?ahin, Onur [Scientific and Technological Research Application and Research Center, Sinop University, 57010 Sinop (Turkey)

2014-02-15

297

Homoleptic ligands vs heteroleptic ligands on coordination polymerizations: Construction and properties of silver(I) coordination polymers containing dialkylbis(4-pyridy)silanes  

NASA Astrophysics Data System (ADS)

Investigations into pure bidentate ligand vs mixed bidentate ligands on self-assembly of AgPF6 with the respective L1, L2, L3, L1/L2, L1/L3, and L2/L3 (L1 = diethylbis(4-pyridyl)silane; L2 = ethylmethylbis(4-pyridyl)silane; L3 = cyclotetramethylenebis(4-pyridyl)silane) were carried out. The self-assembly reactions of AgPF6 with the respective ligand system produce desirable homoleptic or heteroleptic silver(I) coordination polymers. [Ag(L1)2](PF6) gives rise to a tubular loop chain whereas the other five products lead to a twofold interpenetration diamonoid structure. [Ag(L1)2](PF6) shows a strong blue luminescence at 453 nm (?ex = 270 nm), which is useful to recognize alcohols. All products were characterized by thermal analyses, and in particular, calcination of [Ag(L3)2](PF6)?CH3OH at 600 °C finally produces silver(0) microcrystalline morphology.

Park, Minwoo; Jang, Jaeseong; Moon, So Yun; Jung, Ok-Sang

2014-03-01

298

Moment-Preserving SN Discretizations for the One-Dimensional Fokker-Planck Equation  

SciTech Connect

The Fokker-Planck equation: (1) Describes the transport and interactions of charged particles, (2) Many small-angle scattering collisions, (3) Asymptotic limit of the Boltzmann equation (Pomraning, 1992), and (4) The Boltzmann collision operator becomes the angular Laplacian. SN angular discretization: (1) Angular flux is collocated at the SN quadrature points, (2) The second-order derivatives in the Laplacian term must be discretized, and (3) Weighted finite-difference method preserves zeroth and first moments (Morel, 1985). Moment-preserving methods: (1) Collocate the Fokker-Planck operator at the SN quadrature points, (2) Develop several related and/or equivalent methods, and (3) Motivated by discretizations for the angular derivative appearing in the transport equation in one-dimensional spherical coordinates.

Warsa, James S. [Los Alamos National Laboratory; Prinja, Anil K. [Los Alamos National Laboratory

2012-06-14

299

Characterization of Thermal Transport in One-dimensional Solid Materials.  

PubMed

The TET (transient electro-thermal) technique is an effective approach developed to measure the thermal diffusivity of solid materials, including conductive, semi-conductive or nonconductive one-dimensional structures. This technique broadens the measurement scope of materials (conductive and nonconductive) and improves the accuracy and stability. If the sample (especially biomaterials, such as human head hair, spider silk, and silkworm silk) is not conductive, it will be coated with a gold layer to make it electronically conductive. The effect of parasitic conduction and radiative losses on the thermal diffusivity can be subtracted during data processing. Then the real thermal conductivity can be calculated with the given value of volume-based specific heat (?cp), which can be obtained from calibration, noncontact photo-thermal technique or measuring the density and specific heat separately. In this work, human head hair samples are used to show how to set up the experiment, process the experimental data, and subtract the effect of parasitic conduction and radiative losses. PMID:24514072

Liu, Guoqing; Lin, Huan; Tang, Xiaoduan; Bergler, Kevin; Wang, Xinwei

2014-01-01

300

Design and evaluation of omnidirectional one-dimensional photonic crystals  

NASA Astrophysics Data System (ADS)

We have theoretically and experimentally studied a wide range of realistic fabrication parameters for the formation of omnidirectional photonic band gaps (PBGs) in one-dimensional photonic crystals (1D PCs). Photonic band structures in 1D PCs have been analyzed for the cases with and without a defect layer. It is shown that a defect state in the defect-mode PBG behaves like an electronic impurity level in the gap with a change in thickness (i.e., optical path) of the defect layer. Three types of 1D PC structures (Te/polystyrene, Si/SiO2, and ZnS/SiO2), which are designed for applications in the infrared region (especially for the wavelength of 1.55 ?m) and in the visible region, are proposed and demonstrated their high reflectance (R) properties experimentally. For example, a six-pair Si/SiO2 1D PC fabricated with a structure parameter (period=388.5 nm, filling factor=0.406) exhibits a wide range omni-PBGs in the wavelength range of 1310-1742 nm. The measured R spectra are in very good agreement with calculated results. In particular, the R spectra of a ZnS/SiO2 1D PC in the wavelength range of 190-800 nm are almost the same as those calculated using complex refractive indices. We also propose conditions to obtain omni-PBGs and band structures for a high refractive-index ambient medium (n).

Lee, Hyun-Yong; Yao, Takafumi

2003-01-01

301

Drag dynamics in one-dimensional Fermi systems  

E-print Network

We study drag dynamics of several fermions in a fermion cloud in one-dimensional continuous systems, with particular emphasis on the non-trivial quantum many-body effects in systems whose parameters change gradually in real time. We adopt the Fermi--Hubbard model and the time-dependent density matrix renormalization group method to calculate the drag force on a trapped fermion cluster in a cloud of another fermions species with contact interaction. A non-trivial peak in the resistance force is observed in the large cloud density region, and it is suggested that some momentum redistribution processes have a crucial role in the excitation process. We propose a simplified model which explains the detail of the excitation process and also the origin of the resistance peak. This model emphasizes the difference between the full-quantum calculation and the semiclassical calculation, which is the quantum effects, in slow dynamics of many-body systems bound in a fermion cloud.

Jun'ichi Ozaki; Masaki Tezuka; Norio Kawakami

2014-05-02

302

Electronic effects of defects in one-dimensional channels  

NASA Astrophysics Data System (ADS)

As electronic devices shrink to the one-dimensional limit, unusual device physics can result, even at room temperature. Nanoscale conductors like single-walled carbon nanotubes (SWNTs) are particularly useful tools for experimentally investigating these effects. Our characterization of point defects in SWNTs has focused on these electronic consequences. A single scattering site in an otherwise quasi-ballistic SWNT introduces resistance, transconductance, and chemical sensitivity, and here we investigate these contributions using a combination of transport and scanning probe techniques. The transport measurements determine the two-terminal contributions over a wide range of bias, temperature, and environmental conditions, while the scanning probe work provides complementary confirmation that the effects originate at a particular site along the conduction path in a SWNT. Together, the combination proves that single point defects behave like scattering barriers having Poole-Frenkel transport characteristics. The Poole-Frenkel barriers have heights of 10 - 30 meV and gate-dependent widths that grow as large as 1 ?m due to the uniquely poor screening in one dimension. Poole-Frenkel characteristics suggest that the barriers contain at least one localized electronic state, and that this state primarily contributes to conduction under high bias or high temperature conditions. Because these localized states vary from one device to another, we hypothesize that each might be unique to a particular defect's chemical type.

Fuller, Elliot J.; Pan, Deng; Corso, Brad L.; Gul, O. Tolga; Collins, Philip G.

2013-09-01

303

Digital noise generators using one-dimensional chaotic maps  

NASA Astrophysics Data System (ADS)

This work shows how to improve the statistical distribution of signals produced by digital noise generators designed with one-dimensional (1-D) chaotic maps. It also shows that in a digital electronic design the piecewise linear chaotic maps (PWLCM) should be considered because they do not have stability islands in its chaotic behavior region, as it occurs in the case of the logistic map, which is commonly used to build noise generators. The design and implementation problems of the digital noise generators are analyzed and a solution is proposed. This solution relates the output of PWLCM, usually defined in the real numbers' domain, with a codebook of S elements, previously defined. The proposed solution scheme produces digital noise signals with a statistical distribution close to a uniform distribution. Finally, this work shows that it is possible to have control over the statistical distribution of the noise signal by selecting the control parameter of the PWLCM and using, as a design criterion, the bifurcation diagram.

Martínez-Íonthe, J. A.; Palacios-Luengas, L.; Cruz-Irisson, M.; Díaz Méndez, J. A.; Vazquez Medina, R.

2014-05-01

304

`Quantum explosion' of a trapped one-dimensional Bose gas  

E-print Network

We analyze free expansion of a trapped one-dimensional Bose gas after a sudden release from the confining trap potential. By using the stationary phase and local density approximations, we show that the long-time asymptotic density profile and the momentum distribution of the gas are determined by the initial distribution of Bethe rapidities (quasimomenta) and hence can be obtained from the solutions to the thermodynamic Bethe ansatz equations. For expansion from a harmonic trap, and in the limits of very weak and very strong interactions, we recover the known scaling solutions of the hydrodynamic approach corresponding to self-similar expansion. For all other power-law traps and arbitrary interaction strengths, the expansion is not self-similar and shows strong dependence on the trap anharmonicity of the shape variation of the density profile during evolution. We also characterize dynamical fermionization of an expanding cloud in terms of its first- and second-order coherences describing phase and density fluctuations.

A. S. Campbell; D. M. Gangardt; K. V. Kheruntsyan

2015-01-08

305

Statistical properties of one-dimensional parametrically kicked Hamilton systems  

NASA Astrophysics Data System (ADS)

We study the one-dimensional Hamiltonian systems and their statistical behavior, assuming the initial microcanonical distribution and describing its change under a parametric kick, which by definition means a discontinuous jump of a control parameter of the system. Following a previous work by Papamikos and Robnik [J. Phys. A: Math. Theor. 44, 315102 (2011), 10.1088/1751-8113/44/31/315102], we specifically analyze the change of the adiabatic invariant (the action) of the system under a parametric kick: A conjecture has been put forward that the change of the action at the mean energy always increases, which means, for the given statistical ensemble, that the Gibbs entropy in the mean increases. By means of a detailed analysis of a great number of case studies, we show that the conjecture largely is satisfied, except if either the potential is not smooth enough or if the energy is too close to a stationary point of the potential (separatrix in the phase space). Very fast changes in a time-dependent system quite generally can be well described by such a picture and by the approximation of a parametric kick, if the change of the parameter is sufficiently fast and takes place on the time scale of less than one oscillation period. We discuss our work in the context of the statistical mechanics in the sense of Gibbs.

Andresas, Dimitris; Batisti?, Benjamin; Robnik, Marko

2014-06-01

306

Negative Refraction Angular Characterization in One-Dimensional Photonic Crystals  

PubMed Central

Background Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. Methodology/Principal Findings By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Conclusions/Significance Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications. PMID:21494332

Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

2011-01-01

307

Screw dislocation-driven growth of one-dimensional nanomaterials  

NASA Astrophysics Data System (ADS)

Nanoscience and nanotechnology are impacting our lives in many ways, from electronic and photonic devices to biosensors. They also hold the promise of tackling the renewable energy challenges facing us. However, one limiting scientific challenge is the effective and efficient bottom-up synthesis of nanomaterials. In this thesis, we discuss the fundamental theories of screw dislocation-driven growth of various nanostructures including one-dimensional nanowires and nanotubes, two-dimensional nanoplates, and three-dimensional hierarchical tree-like nanostructures. We then introduce the transmission electron microscopy (TEM) techniques to structurally characterize the dislocation-driven nanomaterials for future searching and identifying purposes. We summarize the guidelines for rationally designing the dislocation-driven growth and discuss specific examples to illustrate how to implement the guidelines. We also show that dislocation growth is a general and versatile mechanism that can be used to grow a variety of nanomaterials via distinct reaction chemistry and synthetic methods. The fundamental investigation and development of dislocation-driven growth of nanomaterials will create a new dimension to the rational design and synthesis of increasingly complex nanomaterials.

Meng, Fei

308

Interaction quenches in the one-dimensional Bose gas  

NASA Astrophysics Data System (ADS)

The nonequilibrium dynamics of integrable systems are highly constrained by the conservation of certain charges. There is substantial evidence that after a quantum quench they do not thermalize but their asymptotic steady state can be described by a generalized Gibbs ensemble (GGE) built from the conserved charges. Most of the studies on the GGE so far have focused on models that can be mapped to quadratic systems, while analytic treatment in nonquadratic systems remained elusive. We obtain results on interaction quenches in a nonquadratic continuum system, the one-dimensional (1D) Bose gas described by the integrable Lieb-Liniger model. The direct implementation of the GGE prescription is prohibited by the divergence of the conserved charges, which we conjecture to be endemic to any continuum integrable systems with contact interactions undergoing a sudden quench. We compute local correlators for a noninteracting initial state and arbitrary final interactions as well as two-point functions for quenches to the Tonks-Girardeau regime. We show that in the long time limit integrability leads to significant deviations from the predictions of the grand canonical ensemble, allowing for an experimental verification in cold-atom systems.

Kormos, Márton; Shashi, Aditya; Chou, Yang-Zhi; Caux, Jean-Sébastien; Imambekov, Adilet

2013-11-01

309

Interspecies tunneling in one-dimensional Bose mixtures  

SciTech Connect

We study the ground-state properties and quantum dynamics of few-boson mixtures with strong interspecies repulsion in one-dimensional traps. If one species localizes at the center, e.g., due to a very large mass compared to the other component, it represents an effective barrier for the latter, and the system can be mapped onto identical bosons in a double well. For weaker localization, the barrier atoms begin to respond to the light component, leading to an induced attraction between the mobile atoms that may even outweigh their bare intraspecies repulsion. To explain the resulting effects, we derive an effective Hubbard model for the lighter species accounting for the back action of the barrier in correction terms to the lattice parameters. Also the tunneling is drastically affected: by varying the degree of localization of the 'barrier' atoms, the dynamics of intrinsically noninteracting bosons can change from Rabi oscillations to effective pair tunneling. For identical fermions (or fermionized bosons), this leads to the tunneling of attractively bound pairs.

Pflanzer, Anika C. [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Zoellner, Sascha [Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Koebenhavn O (Denmark); Schmelcher, Peter [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Theoretische Chemie, Universitaet Heidelberg, INF 229, D-69120 Heidelberg (Germany)

2010-02-15

310

Superconductor-Insulator Transition in One Dimensional Josephson Junction Arrays.  

NASA Astrophysics Data System (ADS)

Small capacitance Josephson junctions were fabricated in a one dimensional series array such that the charging energy associated with the capacitance between nearest neighbors, E_C=e^2/2C, was the order of the Josephson Coupling energy. The later could be modulated in a periodic fashion with an externally applied magnetic flux. The electrodes were closely spaced so that the stray capacitance to ground, C0 << C. At low temperatures k_BT << EC , E_J, for certain array parameters, it was possible to tune current-voltage characteristic from Josephson-like behavior (sharp critical current), to Coulomb-blockade-like behavior (sharp critical voltage) with the magnetic field. As the temperature was raised this transition from the superconducting to insulating behavior became less distinct. The temperature dependence of the zero bias resistance, R0 ? dV_rms/dI_rms, measured with a minimal excitation power, dI_rms dV_rms = 10-16 Watt, displayed a clear transition to insulating behavior when R0 > h/4e^2. The work was supported by the Swedish NFR, TFR and the Wallenberg Foundation.

Haviland, D. B.; Delsing, P.; Persson, S. H. M.

1996-03-01

311

Statistical properties of one-dimensional parametrically kicked Hamilton systems.  

PubMed

We study the one-dimensional Hamiltonian systems and their statistical behavior, assuming the initial microcanonical distribution and describing its change under a parametric kick, which by definition means a discontinuous jump of a control parameter of the system. Following a previous work by Papamikos and Robnik [J. Phys. A: Math. Theor. 44, 315102 (2011)], we specifically analyze the change of the adiabatic invariant (the action) of the system under a parametric kick: A conjecture has been put forward that the change of the action at the mean energy always increases, which means, for the given statistical ensemble, that the Gibbs entropy in the mean increases. By means of a detailed analysis of a great number of case studies, we show that the conjecture largely is satisfied, except if either the potential is not smooth enough or if the energy is too close to a stationary point of the potential (separatrix in the phase space). Very fast changes in a time-dependent system quite generally can be well described by such a picture and by the approximation of a parametric kick, if the change of the parameter is sufficiently fast and takes place on the time scale of less than one oscillation period. We discuss our work in the context of the statistical mechanics in the sense of Gibbs. PMID:25019871

Andresas, Dimitris; Batisti?, Benjamin; Robnik, Marko

2014-06-01

312

Conductance distribution in quasi-one-dimensional disordered quantum wires  

NASA Astrophysics Data System (ADS)

We develop a simple systematic method, valid for all strengths of disorder, to obtain analytically the full distribution of conductances P( g) for a quasi-one-dimensional wire within the model of non-interacting fermions. The method has been used in [Phys. Rev. Lett. 83 (1999) 3013; Ann. Phys. (Leipzig) 8 (1999) 753; Phys. Rev. B 66 (2002) 174204; Europhys. Lett. 61 (2003) 95] to predict sharp features in P( g) near g=1 and the existence of non-analyticity in the conductance distribution in the insulating and crossover regimes, as well as to show how P( g) changes from Gaussian to log-normal behavior as the disorder strength is increased. Here we provide many details of the method, including intermediate results that offer much insight into the nature of the solutions. In addition, we show within the same framework that while for metals P( g) is a Gaussian around < g>?1, there exists a log-normal tail for g?1, consistent with earlier field theory calculations. We also obtain several other results that compare very well with available exact results in the metallic and insulating regimes.

Muttalib, K. A.; Wölfle, P.; Gopar, V. A.

2003-11-01

313

Fractal spectra in generalized Fibonacci one-dimensional magnonic quasicrystals  

NASA Astrophysics Data System (ADS)

In this work we carry out a theoretical analysis of the spectra of magnons in quasiperiodic magnonic crystals arranged in accordance with generalized Fibonacci sequences in the exchange regime, by using a model based on a transfer-matrix method together random-phase approximation (RPA). The generalized Fibonacci sequences are characterized by an irrational parameter ?(p,q), which rules the physical properties of the system. We discussed the magnonic fractal spectra for first three generalizations, i.e., silver, bronze and nickel mean. By varying the generation number, we have found that the fragmentation process of allowed bands makes possible the emergence of new allowed magnonic bulk bands in spectra regions that were magnonic band gaps before, such as which occurs in doped semiconductor devices. This interesting property arises in one-dimensional magnonic quasicrystals fabricated in accordance to quasiperiodic sequences, without the need to introduce some deferent atomic layer or defect in the system. We also make a qualitative and quantitative investigations on these magnonic spectra by analyzing the distribution and magnitude of allowed bulk bands in function of the generalized Fibonacci number Fn and as well as how they scale as a function of the number of generations of the sequences, respectively.

Costa, C. H. O.; Vasconcelos, M. S.; Barbosa, P. H. R.; Barbosa Filho, F. F.

2012-07-01

314

Dynamic response of one-dimensional bosons in a trap  

SciTech Connect

We calculate the dynamic structure factor S(q,{omega}) of a one-dimensional (1D) interacting Bose gas confined in a harmonic trap. The effective interaction depends on the strength of the confinement enforcing the (1D) motion of atoms; interaction may be further enhanced by superimposing an optical lattice on the trap potential. In the compressible state, we find that the smooth variation in the gas density around the trap center leads to softening of the singular behavior of S(q,{omega}) at the first Lieb excitation mode compared to the behavior predicted for homogeneous 1D systems. Nevertheless, the density-averaged response S(q,{omega}) remains a nonanalytic function of q and {omega} at the first Lieb excitation mode in the limit of weak trap confinement. The exponent of the power-law nonanalyticity is modified due to the inhomogeneity in a universal way and thus bears unambiguously the information about the (homogeneous) Lieb-Liniger model. A strong optical lattice causes formation of Mott phases. Deep in the Mott regime, we predict a semicircular peak in S(q,{omega}) centered at the on-site repulsion energy, {omega}=U. Similar peaks of smaller amplitudes exist at multiples of U as well. We explain the suppression of the dynamic response with entering into the Mott regime, observed recently by Clement et al. [Phys. Rev. Lett. 102, 155301 (2009)], based on an f-sum rule for the Bose-Hubbard model.

Golovach, Vitaly N. [Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universitaet, 80333 Munich (Germany); Minguzzi, Anna [Laboratoire de Physique et de Modelisation des Milieux Condenses, C.N.R.S., Universite Joseph Fourier, BP 166, 38042 Grenoble (France); Glazman, Leonid I. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States)

2009-10-15

315

One-dimensional surface phonon polaritons in boron nitride nanotubes.  

PubMed

Surface polaritons, which are electromagnetic waves coupled to material charge oscillations, have enabled applications in concentrating, guiding and harvesting optical energy below the diffraction limit. Surface plasmon polaritons involve oscillations of electrons and are accessible in noble metals at visible and near-infrared wavelengths, whereas surface phonon polaritons (SPhPs) rely on phonon resonances in polar materials, and are active in the mid-infrared. Noble metal surface plasmon polaritons have limited applications in the mid-infrared. SPhPs at flat interfaces normally possess long polariton wavelengths and provide modest field confinement/enhancement. Here we demonstrate propagating SPhPs in a one-dimensional material consisting of a boron nitride nanotube at mid-infrared wavelengths. The observed SPhP exhibits high field confinement and enhancement, and a very high effective index (neff~70). We show that the modal and propagation length characteristics of the SPhPs may be controlled through the nanotube size and the supporting substrates, enabling mid-infrared applications. PMID:25154586

Xu, Xiaoji G; Ghamsari, Behnood G; Jiang, Jian-Hua; Gilburd, Leonid; Andreev, Gregory O; Zhi, Chunyi; Bando, Yoshio; Golberg, Dmitri; Berini, Pierre; Walker, Gilbert C

2014-01-01

316

Characterization of Thermal Transport in One-dimensional Solid Materials  

PubMed Central

The TET (transient electro-thermal) technique is an effective approach developed to measure the thermal diffusivity of solid materials, including conductive, semi-conductive or nonconductive one-dimensional structures. This technique broadens the measurement scope of materials (conductive and nonconductive) and improves the accuracy and stability. If the sample (especially biomaterials, such as human head hair, spider silk, and silkworm silk) is not conductive, it will be coated with a gold layer to make it electronically conductive. The effect of parasitic conduction and radiative losses on the thermal diffusivity can be subtracted during data processing. Then the real thermal conductivity can be calculated with the given value of volume-based specific heat (?cp), which can be obtained from calibration, noncontact photo-thermal technique or measuring the density and specific heat separately. In this work, human head hair samples are used to show how to set up the experiment, process the experimental data, and subtract the effect of parasitic conduction and radiative losses. PMID:24514072

Liu, Guoqing; Lin, Huan; Tang, Xiaoduan; Bergler, Kevin; Wang, Xinwei

2014-01-01

317

A one-dimensional model of Nucleosome distribution in DNA  

NASA Astrophysics Data System (ADS)

Nucleosome positioning along DNA is neither random nor precisely regular. Genome-wide maps of nucleosome positions in various eukaryotes have revealed a common pattern around transcription start sites, involving a nucleosome-free region flanked by a periodic pattern in the average nucleosome density. We take a quantitative mathematical description of the nucleosome pattern, and incorporate specifically bound transcription factors. Our model assumes a dense, one-dimensional gas of particles, however, instead of previous work which assumes fixed-size particles interacting only by exclusion, our model explicitly accounts for transient unwrapping of short segments of nucleosomal DNA. Hence, such particles no longer have a fixed size, but interact by an effective repulsive potential. This model has been succesfully used, by us, to provide a unified description of 12 Hemiascomycota yeast species with a single unified set of model parameters. We incorporate into this model, specifically bound particles, or transcription factors (TF), which serve an important role in gene regulation. Nucleosome distribution patterns have an important influence on TF binding, and can even mediate interactions between transcription factors at a distance. This interaction can account for cooperative or competitive binding between these proteins, and we will discuss the implications this can have on gene regulation.

Osberg, Brendan; Moebius, Wolfram; Nguyen, Kien; Gerland, Ulrich

2012-02-01

318

Digital noise generators using one-dimensional chaotic maps  

SciTech Connect

This work shows how to improve the statistical distribution of signals produced by digital noise generators designed with one-dimensional (1-D) chaotic maps. It also shows that in a digital electronic design the piecewise linear chaotic maps (PWLCM) should be considered because they do not have stability islands in its chaotic behavior region, as it occurs in the case of the logistic map, which is commonly used to build noise generators. The design and implementation problems of the digital noise generators are analyzed and a solution is proposed. This solution relates the output of PWLCM, usually defined in the real numbers' domain, with a codebook of S elements, previously defined. The proposed solution scheme produces digital noise signals with a statistical distribution close to a uniform distribution. Finally, this work shows that it is possible to have control over the statistical distribution of the noise signal by selecting the control parameter of the PWLCM and using, as a design criterion, the bifurcation diagram.

Martínez-Ñonthe, J. A; Palacios-Luengas, L.; Cruz-Irisson, M.; Vazquez Medina, R. [Instituto Politécnico Nacional, ESIME-Culhuacan, Santa Ana 1000, 04430, D.F. (Mexico); Díaz Méndez, J. A. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro 1, Tonantzintla, Puebla (Mexico)

2014-05-15

319

Using the NASA GRC Sectored-One-Dimensional Combustor Simulation  

NASA Technical Reports Server (NTRS)

The document is a user manual for the NASA GRC Sectored-One-Dimensional (S-1-D) Combustor Simulation. It consists of three sections. The first is a very brief outline of the mathematical and numerical background of the code along with a description of the non-dimensional variables on which it operates. The second section describes how to run the code and includes an explanation of the input file. The input file contains the parameters necessary to establish an operating point as well as the associated boundary conditions (i.e. how it is fed and terminated) of a geometrically configured combustor. It also describes the code output. The third section describes the configuration process and utilizes a specific example combustor to do so. Configuration consists of geometrically describing the combustor (section lengths, axial locations, and cross sectional areas) and locating the fuel injection point and flame region. Configuration requires modifying the source code and recompiling. As such, an executable utility is included with the code which will guide the requisite modifications and insure that they are done correctly.

Paxson, Daniel E.; Mehta, Vishal R.

2014-01-01

320

Traveling waves in a one-dimensional model of hemodynamics  

NASA Astrophysics Data System (ADS)

We consider a one-dimensional model of hemodynamics—blood flow in the blood vessels—which is based on the Navier-Stokes equations averaged over the cross section of the vessel, and conjugate with a linear or nonlinear model for the elastic wall of the vessel. The objective is to study traveling wave solutions using this model. For such solutions, the system of partial differential equations reduces to an ordinary differential equation of the fourth order. The only singular point of the corresponding system of differential equations is found. It is established that at the singular point, the linearization matrix of the system has real or complex roots for different values of the parameters of the problem. With a special choice of the parameters, it has four complex conjugate roots with a nonzero real part or purely imaginary roots. For this case, the effect of the model parameter corresponding to the viscoelastic response of the vessel wall on the solution is investigated. Numerical experiments are performed to verify and analyze the results, and various modes of blood movement are discussed.

Barlukova, A. M.; Cherevko, A. A.; Chupakhin, A. P.

2014-11-01

321

Aromatic N-oxides in construction of different carboxylate coordination polymers of zinc(II), cadmium(II) and mercury(II)  

NASA Astrophysics Data System (ADS)

The coordination polymers [Zn(C 6H 5COO) 2(PNO)] n ( 1), [Zn 2(C 6H 5COO) 4(4,4'-BPNO)] n ( 2), [Zn 4(C 6H 4C 2O 4) 4(4,4'-BPNO) 2(H 2O) 5] n· nH 2O ( 3), [Cd(C 6H 5COO) 2(PNO)] n ( 4), [Cd 3(C 6H 5COO) 6(4,4'-BPNO) 2] n·2 nH 2O ( 5), [Cd(C 6H 4C 2O 4)(4,4'-BPNO)(H 2O)] n ( 6) and [Hg(C 6H 5COO) 2(4,4'-BPNO) 2] n ( 7), (where PNO = pyridine N-oxide, 4,4'-BPNO = 4,4'-bipyridyl- N,N'-dioxide) are synthesized and structurally characterized. The structures of these coordination polymers exhibit mononuclear to trinuclear nodes built by ligation of carboxylate to metal ions connected by N-oxide ligands. Pyridine N-oxide interconnects metal nodes by acting as ? 2-bridging ligand in complexes 1, and 4. In the linear coordination polymer 2, the paddle wheel structure of zinc(II) benzoate units are interconnected by 4,4'-bipyridyl- N,N'-dioxide which acts as a bidentate spacer ligand adopting a trans ? 2-? 1 : ? 1 coordination mode. The polymeric structure of 3 formed by terephthalate and 4,4'-bipyridyl- N,N'-dioxide with zinc(II) contains self-assembled dinuclear Zn 2O 2 type of carboxylate cores, with 4,4'-bipyridyl- N,N'-dioxide coordinating through cis ? 2-? 1 : ? 1 coordination mode. The cadmium coordination polymer 5, comprising of 4,4'-bipyridyl- N,N'-dioxide and benzoate, has trinuclear cadmium benzoate cores wherein the terminal cadmium ions are interconnected by monodentate 4,4'-bipyridyl- N,N'-dioxide bridges. The coordination polymer 6 comprises of mononuclear cadmium nodes independently bridged by terephthalate and 4,4'-bipyridyl- N,N'-dioxide thereby leading to a 3-fold interpenetrated three dimensional network. Double helical polymeric structure is observed in the coordination polymer 7 derived from mononuclear mercury(II) benzoate nodes bridged by 4,4'-bipyridyl- N,N'-dioxide with cis ? 2-? 1 : ? 1 coordination mode.

Sarma, Rupam; Baruah, Jubaraj B.

2011-09-01

322

One-Dimensional Titanium Dioxide Nanomaterials: Nanowires, Nanorods, and Nanobelts  

E-print Network

Cells X 5.2.2. Polymer-Based Solar Cells AB 5.2.3. Quantum Dot Solar Cells AC 5.3. 1D TiO2-based, and quantum dot (QD) solar cells have all been built on TiO2-based electrodes, which offered the most stable.2. Oriented Attachment (Surfactants Free) D 3.3. Surfactant-Controlled Growth D 3.4. Surface Reaction

Wang, Xudong

323

CuII coordination polymers based on 5-methoxyisophthalate and flexible N-donor ligands: Structures and magnetic properties  

NASA Astrophysics Data System (ADS)

Three CuII coordination polymers, {[Cu2(CH3O-ip)2(bmib)]}n (1), {[Cu2(CH3O-ip)2(bmib)2]}n (2) and {[Cu(CH3O-ip)(bbip)]•2H2O}n (3) (CH3O-H2ip is 5-methoxyisophthalic acid, bmib is 1,4-bis(2-methylimidazol-1-yl)butane and bbip is 1,3-bis(1H-benzimidazolyl)propane), have been synthesized by hydrothermal methods. Complexes 1-3 were structurally characterized by elemental analysis, infrared (IR) spectra and X-ray single-crystal diffraction. Complex 1 shows a 3D six-connected self-penetrating network based on paddlewheel secondary building units. Complex 2 has a 3-fold interpenetrating 3D diamond framework. Complex 3 possesses a 1D tube-like chain. Thermo-gravimetric and magnetic properties of 1-3 were also investigated.

Chang, Xin-Hong; Qin, Jian-Hua; Ma, Lu-Fang; Wang, Li-Ya

2014-04-01

324

Tuning the spin-crossover behaviour of a hydrogen-accepting porous coordination polymer by hydrogen-donating guests.  

PubMed

A Hoffman-like coordination polymer with appreciable porosity and uncoordinated pyridyl groups, namely, [Fe(2,5-bpp){Au(CN)2 }2 ]?x?Solv (2,5-bpp=2,5-bis(pyrid-4-yl)pyridine; Solv=solvent), was synthesised and characterised. A series of fascinating spin-crossover behaviours with abrupt, stepwise and hysteretic features were obtained by exchange with a range of protic solvents (ethanol, n-propanol, isopropyl alcohol, sec-butanol and isobutanol). Guest-host hydrogen-bonding interactions involving the H-accepting site of the framework are primarily responsible for the pronounced cooperativity of these spin-crossover behaviours. Meanwhile, the tunable critical temperatures over a range of about 130?K are presumably attributable to a certain degree of competition between internal pressure and local electronic influences of solvents. PMID:25428657

Li, Jin-Yan; Chen, Yan-Cong; Zhang, Ze-Min; Liu, Wei; Ni, Zhao-Ping; Tong, Ming-Liang

2015-01-19

325

Two new silver(I) coordination polymers with 4,4?-bipyridine and two perfluoro-?-diketonates  

NASA Astrophysics Data System (ADS)

Two coordination polymers (CPs) based on a Ag I/perfluoro-?-diketonate/N-donor ligand, [Ag(4,4'-bpy)(hfa)] n, ( 1) and [Ag(4,4'-bpy)(ttfa)] n ( 2), where 4,4'-bpy is 4,4'-bipyridine, Hhfa is hexafluoroacetylacetone, and Httfa is thenoyltrifluoracetylacetone, were prepared and characterized by elemental analysis, IR and 1H NMR spectroscopy as well as X-ray crystallography and electrochemical properties were studied. The complexes display 1D CPs structurally quite similar to another. The adjacent chains are further interlinked via Ag···Ag, Ag···O contacts to generate 1D ladder (double chains) structures. Abundant weak interactions, such as ?···?, C sbnd H···F, C sbnd H···O and F···F interactions, provide additional assembly forces, leading to 3D supramolecular networks for 1 and 2.

Marandi, Farzin; Ghadermazi, Mohammad; Marandi, Afsaneh; Pantenburg, Ingo; Meyer, Gerd

2011-12-01

326

Synthesis, crystal structure and properties of the novel chiral 3D coordination polymer with S-carboxymethyl- l-cysteine  

Microsoft Academic Search

Reaction of fresh Mn(OH)2 precipitate and S-carboxymethyl-l-cysteine (H2SCMC) in aqueous solution afforded a novel chiral 3D coordination polymer Mn(H2O)(SCMC) 1, which crystallizes in the acentric polar space group P21 with cell constants a=5.079(1)Å, b=9.617(2)Å, c=8.649(2)Å, ?=94.40(3)°, V=421.2(1)Å3, Z=2, and exhibit a SHG effect and ferroelectricity (a remnant polarization Pr=0.0159uCcm?2, coercive field Ec=0.83kVcm?2, saturation of the spontaneous polarization Ps=0.234uCcm?2). To the

Wei Xu; Wen Liu; Fang-Yang Yao; Yue-Qing Zheng

2011-01-01

327

Syntheses, crystal structures and properties of series of 4d-4f ln(III)-Ag(I) heterometallic coordination polymers  

NASA Astrophysics Data System (ADS)

By control of the experimental parameters such as ligands, pH value and reacting temperature, series of three-dimensional (3D) 4d-4f Ln(III)-Ag(I) porous coordination polymers (PCPs) with interesting chain-layer construction, namely, {[LnIIIAgI(na)(ina)(ox)]·2(H2O)}n [Ln=Sm(1), Eu(2), Gd(3), Tb(4), Dy(5), Ho(6), Y(7), Yb(8)], have been successfully synthesized under hydrothermal conditions and structurally characterized. All the complexes are characterized by elemental analyses, FT-IR spectroscopy, Powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Furthermore, the luminescence properties of compounds 2 and 4 and the magsnetic properties of complexes 3 and 5 were also investigated in detail.

Ran, Xing-Rui; Wang, Ning; Xie, Wei-Ping; Xiong, Yan-Ju; Cheng, Qian; Long, Yi; Yue, Shan-Tang; Liu, Ying-Liang

2015-05-01

328

Pressure and Temperature Control of Spin-Switchable Metal-Organic Coordination Polymers from Ab Initio Calculations  

NASA Astrophysics Data System (ADS)

We explore a combination of density-functional theory with supplemented Coulomb U (DFT+U) and ab initio molecular dynamics simulations to investigate the spin-crossover (SCO) phenomenon in coordination polymers. We demonstrate the applicability of the method for the case of bimetallic metal-organic framework Fe2[Nb(CN)8]·(4-pyridinealdoxime)8·2H2O [see S. Ohkoshi et al. Nat. Chem. 3, 564 (2011)NCAHBB1755-433010.1038/nchem.1067]. Our study shows that this approach is capable of capturing the SCO transitions driven by pressure as well as temperature. In addition to discovering novel spin-state transitions, magnetic states involving changes in the long-range magnetic ordering pattern are achieved, thereby offering the tunability of spin states as well as the long-range order of the spins. We compare the SCO transition in the Fe-based framework with a computer designed Mn-based variant.

Tarafder, K.; Kanungo, S.; Oppeneer, P. M.; Saha-Dasgupta, T.

2012-08-01

329

Construction of 1-D 4f and 3d-4f coordination polymers with flexible Schiff base ligands.  

PubMed

Three new lanthanide 1-D coordination polymers ({[Ln(2)(H(2)L)(OAc)(6)]·EtOH·2H(2)O}(n) (Ln = Eu (1), Er (2)) and {YbNiLCl(OAc)(2)(H(2)O)}(n) (3)) and a heterobinuclear complex [YbNiLCl(3)(H(2)O)(3)] (4) are reported which are formed from salen type Schiff-base ligands H(2)L (H(2)L = N,N'-bis(3-methoxysalicylidene)butane-1,4-diamine). The polymeric structures are formed by bridging H(2)L units in the case of 1 and 2, and by acetate groups in 3. The structures of 1-4 were determined by single crystal X-ray crystallographic studies and their luminescence properties in MeCN solution were determined. PMID:21874186

Yang, Xiaoping; Lam, Daniel; Chan, Christopher; Stanley, Julie M; Jones, Richard A; Holliday, Bradley J; Wong, Wai-Kwok

2011-10-14

330

One-dimensional SiOC/C composite nanofibers as binder-free anodes for lithium-ion batteries  

NASA Astrophysics Data System (ADS)

One-dimensional silicon oxycarbide (SiOC)/C composite nanofibers were fabricated by electrospinning and subsequent heat treatment. Introducing carbon matrix to SiOC anode material is an efficient way to accommodate the large volume changes during cycling and also increase the amount of free carbon, which is beneficial for improving the reversible capacity. These SiOC/C composite nanofibers form free-standing conductive membranes that can be used directly as battery electrodes without adding carbon black or polymer binder. Results show that after 80 cycles, the discharge capacity of SiOC/C composite nanofiber anodes is 70% higher than that of Si/C nanofiber anodes and more than 1.5 times larger than those of commercial anodes made from graphite. It is, therefore, demonstrated that one-dimensional SiOC/C nanofibers are promising anode material with large capacities and good cycling stability.

Li, Ying; Hu, Yi; Lu, Yao; Zhang, Shu; Xu, Guanjie; Fu, Kun; Li, Shuli; Chen, Chen; Zhou, Lan; Xia, Xin; Zhang, Xiangwu

2014-05-01

331

Lanthanide coordination polymers based on multi-donor ligand containing pyridine and phthalate moieties: Structures, luminescence and magnetic properties  

NASA Astrophysics Data System (ADS)

A new family of five lanthanide-organic coordination polymers incorporating multi-functional N-hetrocyclic dicarboxylate ligand, namely, [Ln2(Hdpp)2(dpp)2]nLn=Pr(1), Eu(2), Gd(3), Dy(4), Er(5) (H2dpp=1-(3, 4-dicarboxyphenyl) pyridin-4-ol) have been fabricated successfully through solvothermal reaction of 1-(3,4-dicarboxyphenyl)-4-hydroxypyridin-1-ium chloride with trivalent lanthanide salts, and have been characterized systematically. The complexes 1-5 are isomorphous and isostructural. They all feature three dimensional (3D) frameworks based on the interconnection of 1D double chains composed of the binuclear moiety [Ln2(Hdpp)2]4+ basic carboxylate as secondary building unit (SBU). The results of magnetic analysis shows the same bridging fashion of carboxylic group in this case results in the different magnetic properties occurring within lanthanide polymers. Moreover, the Eu(III) and Dy(III) complexes display characteristic luminescence emission in the visible regions.

Feng, Xun; Liu, Lang; Wang, Li-Ya; Song, Hong-Liang; Qiang Shi, Zhi; Wu, Xu-Hong; Ng, Seik-Weng

2013-10-01

332

Small-molecule dynamics and mechanisms underlying the macroscopic mechanical properties of coordinatively cross-linked polymer networks.  

PubMed

Specific metal-ligand coordination between bis-Pd(II) and Pt(II) organometallic cross-linkers and poly(4-vinylpyridine) in DMSO defines a three-dimensional associative polymer network. Frequency-dependent dynamic mechanical moduli of a series of four different bulk materials, measured across several decades of oscillatory strain rates, are found to be quantitatively related through the pyridine exchange rates measured on model Pd(II) and Pt(II) complexes. Importantly, the mechanism of ligand exchange in the networks is found to be the same solvent-assisted pathway observed in the model complexes, and so the bulk mechanical properties are determined by relaxations that occur when the cross-links are dissociated from the polymer backbone. It is how often the cross-links dissociate, independently of how long they remain dissociated, that determines the bulk mechanical properties. The quantitative relationship between bulk materials properties and the kinetics and mechanisms observed in model compounds holds promise for the rational, molecular design of materials with tailored mechanical properties. PMID:16218645

Yount, Wayne C; Loveless, David M; Craig, Stephen L

2005-10-19

333

One dimensional blood flow in a planetocentric orbit  

NASA Astrophysics Data System (ADS)

All life on earth is accustomed to the presence of gravity. When gravity is altered, biological processes can go awry. It is of great importance to ensure safety during a spaceflight. Long term exposure to microgravity can trigger detrimental physiological responses in the human body. Fluid redistribution coupled with fluid loss is one of the effects. In particular, in microgravity blood volume is shifted towards the thorax and head. Sympathetic nervous system-induced vasoconstriction is needed to maintain arterial pressure, while venoconstriction limits venous pooling of blood prevents further reductions in venous return of blood to the heart. In this paper, we modify an existing one dimensional blood flow model with the inclusion of the hydrostatic pressure gradient that further depends on the gravitational field modified by the oblateness and rotation of the Earth. We find that the velocity of the blood flow VB is inversely proportional to the blood specific volume d, also proportional to the oblateness harmonic coefficient J2, the angular velocity of the Earth ?E, and finally proportional to an arbitrary constant c. For c = -0.39073 and ?H = -0.5 mmHg, all orbits result to less blood flow velocities than that calculated on the surface of the Earth. From all considered orbits, elliptical polar orbit of eccentricity e = 0.2 exhibit the largest flow velocity VB = 1.031 m/s, followed by the orbits of inclination i = 45°and 0°. The Earth's oblateness and its rotation contribute a 0.7% difference to the blood flow velocity.

Haranas, Ioannis; Gkigkitzis, Ioannis

2012-05-01

334

One Dimensional Advancing Solidification Front in the Hydrate System  

NASA Astrophysics Data System (ADS)

We use a simplified one dimensional model to study the advancing solidification front of a methane hydrate system fed by gas from below for a laboratory scale problem. We assume the system is initially fully saturated with water, no long range transport of salt by diffusion or advection, and equal density of hydrate and liquid. We express the velocity of the solidification front as a function of the gas supply rate when hydrate formation is not limited by formation kinetics. When the hydrate formation is only limited by formation kinetics, we express the velocity of the solidification front as a function of the methane consumption rate, which is described by an Arrhenius-type equation. By comparing these two types of advancing solidification fronts, we find that the advance of the solidification front will be limited by hydrate formation kinetics if the gas supply rate is greater than 0.2 kg m-2 hour-1. Our analysis is based on the porosity of 0.4, the permeability of 10-13 m2, the temperature of 5 oC, the pressure of 7 MPa and the salinity of 3.5 wt.%. For the same settings, if the gas supply rate is less than 0.2 kg m-2 hour-1, the advancing of the solidification front will be limited by methane advection. We also compare the velocity of the solidification front with the salt diffusion transport. We find that if the gas supply rate is greater than 0.002 kg m-2 hour-1, the advancing of the solidification front will not be influenced by salt diffusion.

You, K.; Flemings, P. B.; Darnell, K.

2013-12-01

335

A novel molecular ladder structure of Cu(II)Ba(II) coordination polymer exhibiting ferromagnetic coupling  

E-print Network

­Ba compound {[Ba(H2O)3(CuL)2]·2H2O}n (H3L = Glycylglycine, N- [1-(2-hydroxyphenyl)propylidene]), has been and structure of a novel molecular ladder [Ba(H2O)3- (CuL)2]·2H2O which exhibits ferromagnetic coupling structure [CuL]2. Barium(II) is 8-coordinated by three water molecules (O(9) to O(11)), three carboxylic

Gao, Song

336

Crystal structures of three lead(II) acetate-bridged di-amino-benzene coordination polymers.  

PubMed

Poly[tris-(acetato-?(2) O,O')(?2-acetato-?(3) O,O':O)tetra-kis-(?3-acetato-?(4) O,O':O:O')bis-(benzene-1,2-di-amine-?N)tetra-lead(II)], [Pb4(CH3COO)8(C6H8N2)2] n , (I), poly[(acetato-?(2) O,O')(?3-acetato-?(4) O,O':O:O')(4-chloro-benzene-1,2-diamine-?N)lead(II)], [Pb(CH3COO)2(C6H7ClN2)] n , (II), and poly[(?(2) O,O')(?3-acetato-?(4) O,O':O:O')(3,4-di-amino-benzo-nitrile-?N)lead(II)], [Pb(CH3COO)2(C7H7N3)] n , (III), have polymeric structures in which monomeric units are joined by bridging acetate ligands. All of the Pb(II) ions exhibit hemidirected coordination. The repeating unit in (I) is composed of four Pb(II) ions having O6, O6N, O7 and O6N coordination spheres, respectively, where N represents a monodentate benzene-1,2-di-amine ligand and O acetate O atoms. Chains along [010] are joined by bridging acetate ligands to form planes parallel to (10-1). (II) and (III) are isotypic and have one Pb(II) ion in the asymmetric unit that has an O6N coordination sphere. Pb2O2 units result from a symmetry-imposed inversion center. Polymeric chains parallel to [100] exhibit hydrogen bonding between the amine and acetate ligands. In (III), additional hydrogen bonds between cyano groups and non-coordinating amines join the chains by forming R 2 (2)(14) rings. PMID:25552994

Geiger, David K; Parsons, Dylan E; Zick, Patricia L

2014-12-01

337

Crystal structures of three lead(II) acetate-bridged di­amino­benzene coordination polymers  

PubMed Central

Poly[tris­(acetato-?2 O,O?)(?2-acetato-?3 O,O?:O)tetra­kis­(?3-acetato-?4 O,O?:O:O?)bis­(benzene-1,2-di­amine-?N)tetra­lead(II)], [Pb4(CH3COO)8(C6H8N2)2]n, (I), poly[(acetato-?2 O,O?)(?3-acetato-?4 O,O?:O:O?)(4-chloro­benzene-1,2-diamine-?N)lead(II)], [Pb(CH3COO)2(C6H7ClN2)]n, (II), and poly[(?2 O,O?)(?3-acetato-?4 O,O?:O:O?)(3,4-di­amino­benzo­nitrile-?N)lead(II)], [Pb(CH3COO)2(C7H7N3)]n, (III), have polymeric structures in which monomeric units are joined by bridging acetate ligands. All of the PbII ions exhibit hemidirected coordination. The repeating unit in (I) is composed of four PbII ions having O6, O6N, O7 and O6N coordination spheres, respectively, where N represents a monodentate benzene-1,2-di­amine ligand and O acetate O atoms. Chains along [010] are joined by bridging acetate ligands to form planes parallel to (10-1). (II) and (III) are isotypic and have one PbII ion in the asymmetric unit that has an O6N coordination sphere. Pb2O2 units result from a symmetry-imposed inversion center. Polymeric chains parallel to [100] exhibit hydrogen bonding between the amine and acetate ligands. In (III), additional hydrogen bonds between cyano groups and non-coordinating amines join the chains by forming R 2 2(14) rings. PMID:25552994

Geiger, David K.; Parsons, Dylan E.; Zick, Patricia L.

2014-01-01

338

Synthesis of microcrystals of the [Fe(L)(bipy)] spin crossover coordination polymer in a poly-4-vinylpyridine matrix.  

PubMed

Microcrystals of the spin-crossover coordination polymer [FeL(bipy)] (L=[3,3']-[1,2-phenylenebis(iminoethylidyne)]bis-(2,4-pentanedionato)(2-), bipy=4,4'-bipyridine) have been prepared in a poly(4-vinylpyridine) (P4VP) matrix. This was done by sequential addition of the iron(II) precursor complex and the bridging ligand bipy to a P4VP matrix, and by repetition of this cycle. The obtained composite material was characterized using TEM, SEM, XRPD, and SQUID measurements, and Mössbauer spectroscopy. With repeating cycles, the size of the [FeL(bipy)] crystals in the P4VP matrix increases from submicrometer to micrometer dimensions. A strong dependence on the number of cycles is observed. Above a critical size and concentration, the microcrystals show the same cooperative spin transition as the bulk material. No indication for a gradual spin transition is observed, but the remaining iron centers are either high-spin or low-spin depending on the coordination environment. PMID:24938532

Göbel, Christoph; Palamarciuc, Tatiana; Lochenie, Charles; Weber, Birgit

2014-08-01

339

When Cu4I4 cubane meets Cu3(pyrazolate)3 triangle: dynamic interplay between two classical luminophores functioning in a reversibly thermochromic coordination polymer.  

PubMed

A supramolecular dual emissive system incorporating two classical copper(I)-cluster-based luminophores, namely, Cu(4)I(4) and Cu(3)Pz(3) (Pz = pyrazolate), is reported. The targeted luminescent coordination polymer exhibits reversible thermochromism spanning from green to orange-red. PMID:21892509

Zhan, Shun-Ze; Li, Mian; Zhou, Xiao-Ping; Wang, Jun-Hao; Yang, Ju-Rong; Li, Dan

2011-12-14

340

Size effect of the effective temperature in one-dimensional material  

NASA Astrophysics Data System (ADS)

Thermal radiation properties of non-uniform temperature distribution for one-dimensional materials are investigated. The effective temperature is derived for non-uniform temperature distribution and the size effect of the effective temperature is derived in one-dimensional material. The effective temperature of one-dimensional material is shown as a function of the length.

Kim, Heetae; Kim, Woo Kang; Park, Gunn-Tae; Park, Chang-Soo; Cho, Hak Dong

2014-11-01

341

Syntheses, structures and magnetic properties of four coordination polymers based on nitrobenzene dicarboxylate and various N-donor coligands  

NASA Astrophysics Data System (ADS)

Four new coordination polymers {[Ni(4-Nbdc)(bpa)(H2O)]}n (1), {[Co(4-Nbdc)(bpp) (H2O)]}n (2), {[Ni(4-Nbdc)(bpp)(H2O)]·H2O}n (3), and {[Mn2(3-Nbdc)2(bib)3]·2H2O}n (4) (4-Nbdc=4-nitrobenzene-1,2-dicarboxylate, 3-Nbdc=3-nitrobenzene-1,2-dicarboxylate, bpa=1,2-bi(4-pyridyl)ethane, bpp=1,3-bis(4-pyridyl)propane, and bib=1,4-bis(1-imidazoly)benzene), were synthesized by hydrothermal reactions, and characterized by single-crystal X-ray diffractions, elemental analysis, FT-IR, PXRD, TGA and magnetic analysis. Complexes 1 and 2 display quasi-trapezoidal chain and brick-wall layer, and both of them contain metal-carboxylate binuclear units. Complexes 3 and 4 exhibit three-dimensional frameworks with the (66) dia topology and (44.610.8)(44.62) fsc topology, and both of them contain metal-carboxylate chains. The carboxyl groups with syn-anti coordination mode mediate effectively the weak ferromagnetic coupling interaction within Ni(II)-carboxylate binuclear in 1 (J=1.27 cm-1) and Ni(II)-carboxylate chain in 3 (J=1.44 cm-1), respectively, and the carboxyl groups with anti-anti coordination mode leads to the classic antiferromagnetic coupling interaction within Mn(II)-carboxylate chain in 4 (J=-0.77 cm-1).

Li, Gui-Lian; Yin, Wei-Dong; Liu, Guang-Zhen; Ma, Lu-Fang; Wang, Li-Ya

2014-12-01

342

Ultra-sensitive thermal conductance measurement of one-dimensional nanostructures enhanced by differential bridge  

NASA Astrophysics Data System (ADS)

Thermal conductivity of one-dimensional nanostructures, such as nanowires, nanotubes, and polymer chains, is of significant interest for understanding nanoscale thermal transport phenomena as well as for practical applications in nanoelectronics, energy conversion, and thermal management. Various techniques have been developed during the past decade for measuring this fundamental quantity at the individual nanostructure level. However, the sensitivity of these techniques is generally limited to 1 × 10-9 W/K, which is inadequate for small diameter nanostructures that potentially possess thermal conductance ranging between 10-11 and 10-10 W/K. In this paper, we demonstrate an experimental technique which is capable of measuring thermal conductance of ˜10-11 W/K. The improved sensitivity is achieved by using an on-chip Wheatstone bridge circuit that overcomes several instrumentation issues. It provides a more effective method of characterizing the thermal properties of smaller and less conductive one-dimensional nanostructures. The best sensitivity experimentally achieved experienced a noise equivalent temperature below 0.5 mK and a minimum conductance measurement of 1 × 10-11 W/K. Measuring the temperature fluctuation of both the four-point and bridge measurements over a 4 h time period shows a reduction in measured temperature fluctuation from 100 mK to 0.6 mK. Measurement of a 15 nm Ge nanowire and background conductance signal with no wire present demonstrates the increased sensitivity of the bridge method over the traditional four-point I-V measurement. This ultra-sensitive measurement platform allows for thermal measurements of materials at new size scales and will improve our understanding of thermal transport in nanoscale structures.

Wingert, Matthew C.; Chen, Zack C. Y.; Kwon, Shooshin; Xiang, Jie; Chen, Renkun

2012-02-01

343

Ultra-sensitive thermal conductance measurement of one-dimensional nanostructures enhanced by differential bridge.  

PubMed

Thermal conductivity of one-dimensional nanostructures, such as nanowires, nanotubes, and polymer chains, is of significant interest for understanding nanoscale thermal transport phenomena as well as for practical applications in nanoelectronics, energy conversion, and thermal management. Various techniques have been developed during the past decade for measuring this fundamental quantity at the individual nanostructure level. However, the sensitivity of these techniques is generally limited to 1 × 10(-9) W?K, which is inadequate for small diameter nanostructures that potentially possess thermal conductance ranging between 10(-11) and 10(-10) W?K. In this paper, we demonstrate an experimental technique which is capable of measuring thermal conductance of ?10(-11) W?K. The improved sensitivity is achieved by using an on-chip Wheatstone bridge circuit that overcomes several instrumentation issues. It provides a more effective method of characterizing the thermal properties of smaller and less conductive one-dimensional nanostructures. The best sensitivity experimentally achieved experienced a noise equivalent temperature below 0.5 mK and a minimum conductance measurement of 1 × 10(-11) W?K. Measuring the temperature fluctuation of both the four-point and bridge measurements over a 4 h time period shows a reduction in measured temperature fluctuation from 100 mK to 0.6 mK. Measurement of a 15 nm Ge nanowire and background conductance signal with no wire present demonstrates the increased sensitivity of the bridge method over the traditional four-point I-V measurement. This ultra-sensitive measurement platform allows for thermal measurements of materials at new size scales and will improve our understanding of thermal transport in nanoscale structures. PMID:22380117

Wingert, Matthew C; Chen, Zack C Y; Kwon, Shooshin; Xiang, Jie; Chen, Renkun

2012-02-01

344

Derivation and Testing of Explicit Equations of Motion for Polymers Described by Internal Coordinates  

NASA Astrophysics Data System (ADS)

General Lagrange's equations of motion for a system of polymeric molecules are obtained in an explicit form. They can be used for simulating molecular dynamics of large molecules. The molecular conformations are described by internal coordinates, i.e., bond lengths, valence angles, and torsion angles. The equations derived permit any internal degrees of freedom to be frozen. The method is applied to an oligopeptide in an ?-helical conformation. Three models of the molecule with different degrees of fixation are compared. It is shown that the method permits one to increase significantly the time step in molecular dynamics calculations.

Mazur, A. K.; Dorofeev, V. E.; Abagyan, R. A.

1991-02-01

345

Design and solvothermal synthesis of luminescent copper(I)-pyrazolate coordination oligomer and polymer frameworks.  

PubMed

Two luminescent coordination compounds, [Cu(Pz)]3 (1) and [Cu2(Bpz)]n (2), were isolated from solvothermal reactions of Cu(NO3)2 with 3,5-dimethylpyrazole (HPz) and 3,3',5,5'-tetra-methyl-4,4'-bipyrazole (H2Bpz) respectively in the presence of NH3, of which 1 was revealed to be a planar trimer and 2 a three-dimensional framework, presenting a rare 3-connected binodal (6(2).10)(6.10(2)) topology and eight-fold interpenetration. PMID:17007392

He, Jun; Yin, Ye-Gao; Wu, Tao; Li, Dan; Huang, Xiao-Chun

2006-07-21

346

A series of M-M' heterometallic coordination polymers: syntheses, structures and surface photoelectric properties (M=Ni/Co, M'=Cd/Zn)  

SciTech Connect

Four new heterometallic polymers, [NiCd(mal){sub 2}(H{sub 2}O){sub 2}]n.2nH{sub 2}O 1, [NiZn{sub 2}(Hcit){sub 2}(H{sub 2}O){sub 2}]n 2, [CoCd{sub 2}(Hcit){sub 2}(H{sub 2}O){sub 2}]n 3, [CoZn{sub 2}(Hcit){sub 2}(H{sub 2}O){sub 2}]n 4 (H{sub 2}mal=malonic acid, H{sub 4}cit=citric acid) were synthesized and characterized. The photoelectric properties of the polymers were discussed by the surface photovoltage spectroscopy (SPS). The structural analyses indicate 1 is a Ni-Cd heterometallic polymer with 3D structure bridged by the mal{sup 2-} group. 2-4 are all heterometallic polymers with 2D structures bridged by the Hcit{sup 3-} group. The results of SPS for the four polymers reveal that there are wide photovoltage response bands in the range of 300-800 nm, which indicates that they all possess photoelectric conversion properties. By the introduction of the other metals, the SPS of heterometallic polymers are broadened obviously than the SPS of monometallic complexes. Moreover, the relationships between SPS and UV-Vis absorption spectra have been discussed. -- Graphical Abstract: Four heterometallic polymers, Ni-Cd, Ni-Zn, Co-Cd, Co-Zn, were synthesized and characterized. The photoelectric properties of heterometallic polymers were discussed by SPS. The introduction of heterometallic ions will broaden the SPS of corresponded monometallic complexes. Display Omitted highlights: > Four new heterometallic coordination polymers were reported. > The surface photoelectric properties of heterometallic polymers were studied by SPS. > They all possess photoelectric conversion properties. > The SPS of heterometallic polymers are broadened than that of monometallic complexes.

Li, Lei [School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Niu, Shu-Yun, E-mail: syniu@sohu.co [School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Jin, Jing; Meng, Qin; Chi, Yu-Xian; Xing, Yong-Heng [School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Zhang, Guang-Ning [Institute of Chemistry for Functionalized Materials, Liaoning Normal University, Dalian 116029 (China)

2011-05-15

347

A renormalisation group study of one-dimensional contact processes  

NASA Astrophysics Data System (ADS)

In principle all phenomena in nature can be described by fundamental physical laws. For realistic macroscopic systems the number of degrees of freedom is often too high. Instead, statistical approximative techniques are used. The best known case is represented by models for thermal equilibrium described by the Gibbs ensemble. Most systems in nature are however not in thermal equilibrium . In this thesis one such type of systems is considered: reaction-diffusion systems. The main concept of reaction diffusion systems is that particles diffuse and/or react in a medium. In order to model the stochastic dynamics of these systems, a Markov process is used on a discrete configuration space. The master equation, describing the time evolution of such a process, can formally be interpreted as a Schrodinger equation in imaginary time. In this approach, the (non-Hermitian) generator of the process plays the role of the Hamiltonian. This mathematical equivalence permits the successful application to stochastic systems of a number of exact, approximative or numerical methods from quantum mechanics. In this thesis real-space renormalisation group techniques are applied to study stochastic models on a one-dimensional lattice. The critical behaviour and the universality of absorbing state phase transitions are studied. First, the standard renormalisation group ( SRG) is adapted to a stochastic context resulting in one of the few analytical techniques capable of producing approximations for systems that can not be solved exactly. The SRG is successfully applied to the contact process. Next a generalisation of the contact process to a model with several absorbing states is studied by means of the density matrix renormalisation group (DMRG) algorithm. Finally the experience of the previous two projects is used in the investigation of the quenched random contact process. In the limit of strong disorder exact results are derived for this model. It is the first time exact critical exponents are found for a phase transition out of an absorbing state. Moreover, the exponents are the same as those previously found in a class of disordered quantum chains, suggesting a new kind of universality for strongly disordered systems.

Hooyberghs, Jef J. D.

348

Molecular Self-Assembly into One-Dimensional Nanostructures  

PubMed Central

CONSPECTUS Self-assembly of small molecules into one-dimensional nanostructures offers many potential applications in electronically and biologically active materials. The recent advances discussed in this Account demonstrate how researchers can use the fundamental principles of supramolecular chemistry to craft the size, shape, and internal structure of nanoscale objects. In each system described here, we used atomic force microscopy (AFM) and transmission electron microscopy (TEM) to study the assembly morphology. Circular dichroism, nuclear magnetic resonance, infrared, and optical spectroscopy provided additional information about the self-assembly behavior in solution at the molecular level. Dendron rod–coil molecules self-assemble into flat or helical ribbons. They can incorporate electronically conductive groups and can be mineralized with inorganic semiconductors. To understand the relative importance of each segment in forming the supramolecular structure, we synthetically modified the dendron, rod, and coil portions. The self-assembly depended on the generation number of the dendron, the number of hydrogen-bonding functions, and the length of the rod and coil segments. We formed chiral helices using a dendron–rod–coil molecule prepared from an enantiomerically enriched coil. Because helical nanostructures are important targets for use in biomaterials, nonlinear optics, and stereoselective catalysis, researchers would like to precisely control their shape and size. Tripeptide-containing peptide lipid molecules assemble into straight or twisted nanofibers in organic solvents. As seen by AFM, the sterics of bulky end groups can tune the helical pitch of these peptide lipid nanofibers in organic solvents. Furthermore, we demonstrated the potential for pitch control using trans-to-cis photoisomerization of a terminal azobenzene group. Other molecules called peptide amphiphiles (PAs) are known to assemble in water into cylindrical nanostructures that appear as nanofiber bundles. Surprisingly, TEM of a PA substituted by a nitrobenzyl group revealed assembly into quadruple helical fibers with a braided morphology. Upon photocleavage of this the nitrobenzyl group, the helices transform into single cylindrical nanofibers. Finally, inspired by the tobacco mosaic virus, we used a dumbbell-shaped, oligo(phenylene ethynylene) template to control the length of a PA nanofiber self-assembly (<10 nm). AFM showed complete disappearance of long nanofibers in the presence of this rigid-rod template. Results from quick-freeze/deep-etch TEM and dynamic light scattering demonstrated the templating behavior in aqueous solution. This strategy could provide a general method to control size the length of non-spherical supramolecular nanostructures. PMID:18754628

PALMER, LIAM C.; STUPP, SAMUEL I.

2008-01-01

349

Bioinspired one-dimensional materials for directional liquid transport.  

PubMed

One-dimensional materials (1D) capable of transporting liquid droplets directionally, such as spider silks and cactus spines, have recently been gathering scientists' attention due to their potential applications in microfluidics, textile dyeing, filtration, and smog removal. This remarkable property comes from the arrangement of the micro- and nanostructures on these organisms' surfaces, which have inspired chemists to develop methods to prepare surfaces with similar directional liquid transport ability. In this Account, we report our recent progress in understanding how this directional transport works, as well our advances in the design and fabrication of bioinspired 1D materials capable of transporting liquid droplets directionally. To begin, we first discuss some basic theories on droplet directional movement. Then, we discuss the mechanism of directional transport of water droplets on natural spider silks. Upon contact with water droplets, the spider silk undergoes what is known as a wet-rebuilt, which forms periodic spindle-knots and joints. We found that the resulting gradient of Laplace pressure and surface free energy between the spindle-knots and joints account for the cooperative driving forces to transport water droplets directionally. Next, we discuss the directional transport of water droplets on desert cactus. The integration of multilevel structures of the cactus and the resulting integration of multiple functions together allow the cactus spine to transport water droplets continuously from tip to base. Based on our studies of natural spider silks and cactus spines, we have prepared a series of artificial spider silks (A-SSs) and artificial cactus spines (A-CSs) with various methods. By changing the surface roughness and chemical compositions of the artificial spider silks' spindle-knots, or by introducing stimulus-responsive molecules, such as thermal-responsive and photoresponsive molecules, onto the spindle-knots, we can reversibly manipulate the direction of water droplet's movement on the prepared A-SSs. In addition, the A-SSs with nonuniform spindle-knots, such as multilevel sized spindle-knots and gradient spindle-knots, further demonstrate integrated directional transport ability for water droplets. Through mimicking the main principle of cactus spines in transporting water droplets, we were able to fabricate both single and array A-CSs, which are able to transport liquid droplets directionally both in air and under water. Lastly, we demonstrated some applications of this directional liquid transport, from aspects of efficient fog collection to oil/water separation. In addition, we showed some potential applications in smart catalysis, tracer substance enrichment, smog removal, and drug delivery. PMID:25019657

Ju, Jie; Zheng, Yongmei; Jiang, Lei

2014-08-19

350

Time Dependent Monochromatic Scattering of Radiation in One Dimensional Media: Analytical and Numerical Solutions  

E-print Network

In order to choose a numerical method for solving the time dependent equations of radiative transport, we obtain an exact solution for the time dependent radiation field in a one dimensional infinite medium with monochromatic, isotropic scattering for sources with an arbitrary spatial distribution and an arbitrary time variation of their power. The Lax-Wendroff method seems to be the most suitable. Because it is assumed that radiation delay is caused by the finite speed of light, the following difficulty arises when the numerical method is used: the region of variation of the variables (dimensionless coordinate \\tau and time t) is triangular (the inequality \\tautime and coordinate. By comparing the numerical and exact solutions for a point source with a given time dependence for its power and with pure scattering, the steps in the variables required to obtain a desired accuracy are estimated. This numerical method can be used to calculate the intensity and polarization of the radiation from sources in the early universe during epochs close to the recombination epoch.

D. I. Nagirner; S. L. Kirusheva

2008-08-25

351

Propagation of Lamb waves in one-dimensional radial phononic crystal plates with periodic corrugations  

NASA Astrophysics Data System (ADS)

In this paper, we theoretically investigate the propagation characteristics of Lamb waves in one-dimensional radial phononic crystal plates with periodic corrugations. The dispersion relations, the power transmission spectra, and the displacement fields of the eigenmodes are calculated by using the finite element method based on two-dimensional axial symmetry models in cylindrical coordinates. The axial symmetry model is validated by three-dimensional finite element model in rectangular coordinates. The effects of the geometrical parameters on the band gaps are further explored numerically. Numerical results show that several complete band gaps with a variable bandwidth exist for Lamb waves in the proposed structures. The formation mechanism of opening the acoustic band gaps is attributed to the coupling between the Lamb modes and the corrugation mode. The band gaps are significantly dependent upon the geometrical parameters such as the corrugation height, the corrugation width, and the plate thickness. Significantly, as the increase of corrugation height, band width shifts, new band gaps appear, the bands become flat, and the corrugation mode plays a more prominent role in the opening of Lamb wave band gaps. These properties of Lamb waves in the radial phononic crystal plates can potentially be applied to optimize band gaps, generate filters, and design acoustic devices.

Li, Yinggang; Chen, Tianning; Wang, Xiaopeng; Yu, Kunpeng; Chen, Weihua

2014-02-01

352

High resolution scanning tunneling microscopy of a 1D coordination polymer with imidazole-based N,N,O ligands on HOPG.  

PubMed

Novel ?(3) -N,N,O ligands tend to form 1D coordination polymer strands. Deposition of 1D structures on highly oriented pyrolytic graphite (HOPG) was achieved from diluted solutions and polymer strands have been studied on HOPG by AFM/STM. Single strands were mapped by STM and their electronic properties were subsequently characterized by current imaging tunneling spectroscopy (CITS). Periodic density functional calculations simulating a polymer strand deposited on a HOPG surface are in agreement with the zig-zag structure indicated by experimental findings. Both the observed periodicity and the Zn-Zn distances can be reproduced in the simulations. Van der Waals interactions were found to play a major role for the geometry of the isolated polymer strand, for the adsorption geometry on HOPG, as well as for the adsorption energy. PMID:25077463

Fischer, Nina V; Mitra, Utpal; Warnick, Karl-Georg; Dremov, Viacheslav; Stocker, Michael; Wölfle, Thorsten; Hieringer, Wolfgang; Heinemann, Frank W; Burzlaff, Nicolai; Görling, Andreas; Müller, Paul

2014-09-01

353

Classical and quantum aspects of strongly interacting one-dimensional systems  

NASA Astrophysics Data System (ADS)

We present theoretical investigations of one-dimensional (1D) systems, both classical and quantum in the limit of very large repulsive interactions and low temperatures. We first focus on the influence of disorder on the classical plasma modes of a 1D array of charges or classical Wigner crystal. The dynamical matrix structure is a physical realization of a random Euclidian matrix, where the equilibrium coordinates of the particles are its Hessian stationary points. Calculations on finite-sized systems reveal a mobility edge of the plasma modes by which a spectral variable w2c separates extended and localized plasma modes. This disorder-induced criticality can be placed in the context of a more general set of 1D models that exhibit delocalization due to the interplay of disorder and long-range interactions. However, our 1D Wigner crystal model represents a new symmetry class of random matrices. Furthermore, a complete localization transition consistent with Anderson localization is observed at a critical value of the relative disorder strength kappac. Remarkably, a structural transition into an amorphous solid occurs in the immediate neighborhood of this particular kappac. We develop a phase diagram that outlines the existence of a localized, glassy regime divided from a quasi-long range crystalline ordered regime with a plasmon mobility edge. In our investigations of the quantum aspects strongly interacting 1D systems we combine the first-quantized path-integral formalism and bosonization to develop a phenomenological theory for spin-charge coupled dynamics in one-dimensional ferromagnetic systems with strong interparticle repulsion, at low temperatures. Our theory assumes an initial spin-charge separation where Luttinger-liquid plasmons are explicitly coupled to Heisenberg ferromagnetic spin-waves. The dynamic spin structure severely suppresses the plasmon peak in the single-particle propagator, in both fermionic and bosonic systems. Our analysis provides an effective theory for the new universality class of one-dimensional ferromagnetic systems, capturing both the trapped spin and propagating spin-wave regimes of the long-time behavior.

Akhanjee, Shimul

354

Assembling supramolecular networks by halogen bonding in coordination polymers driven by 5-bromonicotinic acid  

NASA Astrophysics Data System (ADS)

A series of six coordination compounds {[Zn(5-Brnic)2]·1.5H2O}n (1), [Cd(5-Brnic)2]n (2), [Co(5-Brnic)2(H2O)2]n (3), [Zn(5-Brnic)2(H2biim)]n (4), {[Cd(5-Brnic)2(phen)]·H2O}n (5), and [Pb(5-Brnic)2(phen)] (6) have been generated by the hydrothermal method from the metal(II) nitrates, 5-bromonicotinic acid (5-BrnicH), and an optional ancillary 1,10-phenanthroline (phen) or 2,2?-biimidazole (H2biim) ligand. All the products 1-6 have been characterized by IR spectroscopy, elemental, thermal, powder and single-crystal X-ray diffraction analyses. Their 5-bromonicotinate-driven structures vary from the 3D metal-organic framework with the seh-3,5-P21/c topology (in 2) and the 2D interdigitated layers with the sql topology (in 1 and 3), to the 1D chains (in 4 and 5) and the 0D discrete monomers (in 6). The 5-bromonicotinate moiety acts as a versatile building block and its tethered bromine atom plays a key role in reinforcing and extending the structures into diverse 3D supramolecular networks via the various halogen bonding Br⋯O, Br⋯Br, and Br⋯? interactions, as well as the N-H⋯O and C-H⋯O hydrogen bonds. The obtained results demonstrate a useful guideline toward engineering the supramolecular architectures in the coordination network assembly under the influence of various halogen bonding interactions. The luminescent (for 1, 2, 4, 5, and 6) and magnetic (for 3) properties have also been studied and discussed in detail.

Gu, Jin-Zhong; Wu, Jiang; Kirillov, Alexander M.; Lv, Dong-Yu; Tang, Yu; Wu, Jin-Cai

2014-05-01

355

Applications of One-Dimensional Nanomaterials for Stretchable Electronics  

NASA Astrophysics Data System (ADS)

Electronics that can be stretched and/or conformal to curvilinear surfaces has recently attracted broad attention. Success of stretchable electronics depends on the availability of electronic materials and structures that can be highly stretched, compressed, bent, and twisted. One-dimensional (1D) nanomaterials are expected to aid the development of the stretchable electronic systems by improving performance, expanding integration possibilities, and potentially lowering cost, due to their superior mechanical/electronic/optical properties, high aspect ratios, and compatibility with bulk synthesis. This dissertation is primarily focused on the application of 1D nanomaterials, including silicon nanowires (SiNWs), carbon nanotubes (CNTs) and silver nanowires (AgNWs) for stretchable electronics. The mechanical properties of SiNWs, grown by the vapor-liquid-solid process, were first studied with in situ tensile tests inside a scanning electron microscope (SEM). It was found that the fracture strain increased from 2.7% to about 12% when the NW diameter decreased from 60 to 15 nm. The Young's modulus decreased while the fracture strength increased up to 12.2 GPa, as the nanowire diameter decreased. The fracture strength also increased with the decrease of the side surface area. Repeated loading and unloading during tensile tests demonstrated that the nanowires are linear elastic until fracture without appreciable plasticity. Then, SiNW coils were fabricated on elastomeric substrates by a controlled buckling process. SiNWs were first transferred onto prestrained and ultraviolet/ozone (UVO)-treated poly(dimethylsiloxane) (PDMS) substrates and buckled upon release of the prestrain. Two buckling modes (the in-plane wavy mode and the three-dimensional coiled mode) were found; a transition between them was achieved by controlling the UVO treatment of PDMS. Structural characterization revealed that the NW coils were oval-shaped. The oval-shaped NW coils exhibited very large stretchability up to the failure strain of PDMS (˜104% in our study). Such a large stretchability relies on the effectiveness of the coil shape in mitigating the maximum local strain, with a mechanics that is similar to the motion of a coil spring. Single NW devices based on coiled NWs were demonstrated with a nearly constant electrical response in a large strain range. In addition to the wavy shape, the coil shape represents an effective architecture in accommodating large tension, compression, bending, and twist, which may find important applications for stretchable electronics and other stretchable technologies. For CNTs, wavy CNT ribbons coated with a thin layer of Au/Pd film were fabricated on PDMS substrates through mechanical buckling. Covered with a top layer of PDMS, the wavy CNT ribbons are able to accommodate large stretching (up to 100%) with little change in resistance. Significantly, a new manufacturing strategy for buckling of aligned CNTs was developed, which does not involve prestretching the substrate but relies on the interface interaction between the CNTs and the substrate. More specifically, upon stretching the substrate the CNTs slide on the substrate, but upon releasing the CNTs buckle. Following this manufacturing strategy, stretchable conductors based on aligned CNTs were demonstrated. At last, a highly conductive and stretchable conductor with AgNWs embedded just below the surface of PDMS was fabricated. Stable conductivity of 5,285 S cm-1 was achieved in a large range of tensile strain (0-50%) after a few cycles of stretching/releasing of the substrate. This stable electric response is due to buckling of the AgNW/PDMS thin layer, which is attributed to irreversible sliding of the AgNWs in the PDMS matrix. AgNWs can be printed to fabricate patterned stretchable conductors with feature size as small as 50 microm. Furthermore, a stretchable light emitting diode (LED) circuit and a capacitive strain sensor were demonstrated using the AgNW-based stretchable conductors as interconnects or electrodes.

Xu, Feng

356

A novel two-dimensional Cd(II) coordination polymer: poly[aqua[??-2-(4-carboxylatobenzoyl)benzoato]cadmium(II)].  

PubMed

The title Cd(II) coordination framework, [Cd(C15H8O5)(H2O)]n or [Cd(bpdc)(H2O)]n [H2bpdc is 2-(4-carboxybenzoyl)benzoic acid], has been prepared and characterized using IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. Each Cd(II) centre is six-coordinated by two O atoms from one 2-(4-carboxylatobenzoyl)benzoate (bpdc(2-)) ligand in chelating mode, three O-donor atoms from three other bpdc(2-) anions and one O atom from a coordinated water molecule in an octahedral coordination environment. Two crystallographically equivalent Cd(II) cations are bridged by one O atom of the 2-carboxylate group of one bpdc(2-) ligand and by both O atoms of the 4-carboxylate group of a second bpdc(2-) ligand to form a binuclear [(Cd)2(O)(OCO)] secondary building unit. Adjacent secondary building units are interlinked to form a one-dimensional [Cd(OCO)2]n chain. The bpdc(2-) ligands link these rod-shaped chains to give rise to a complex two-dimensional [Cd(bpdc)]n framework with a 4,4-connected binodal net topology of point symbol {4(3).6(2).8}. The compound exhibits a strong fluorescence emission and typical ferroelectric behaviour in the solid state at room temperature. PMID:25370111

Chen, Hui-Ru; Zhang, Wen-Wen

2014-11-01

357

Syntheses, crystal structures, and water adsorption behaviors of jungle-gym-type porous coordination polymers containing nitro moieties  

SciTech Connect

NO{sub 2} containing dicarboxylate bridging ligands, nitroterephthalate (bdc-NO{sub 2}) and 2,5-dinitroterephthalate (bdc-(NO{sub 2}){sub 2}), afford porous coordination polymers, {l_brace}[Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)].solvents{r_brace}{sub n} (2 contains solvents) and {l_brace}[Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)].solvents{r_brace}{sub n} (3 contains solvents). Both compounds form jungle-gym-type regularities, where a 2D square grid composed of dinuclear Zn{sub 2} units and dicarboxylate ligands is bridged by dabco molecules to extend the 2D layers into a 3D structure. In 2 contains solvents and 3 contains solvents, a rectangle pore surrounded by eight Zn{sub 2} corners contains two and four NO{sub 2} moieties, respectively. Thermal gravimetry (TG) and X-ray powder diffraction (XRPD) measurements reveal that both compounds maintain the frameworks regularities without guest molecules and with solvents such as MeOH, EtOH, i-PrOH, and Me{sub 2}CO. Adsorption measurements reveal that dried 2 and 3 adsorb H{sub 2}O molecules to be {l_brace}[Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)].4H{sub 2}O{r_brace}{sub n} (2 contains 4H{sub 2}O) and {l_brace}[Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)].6H{sub 2}O{r_brace}{sub n} (3 contains 6H{sub 2}O), showing the pore hydrophilicity enhancement caused by NO{sub 2} group introduction. - Graphical abstract: Two hydrophilic porous coordination polymers, [Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)]{sub n} (2, bdc-NO{sub 2}=nitroterephthalate, dabco=1,4-diazabicyclo[2.2.2]octane) and [Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)]{sub n} (3, bdc-(NO{sub 2}){sub 2}=2,5-dinitroterephthalate), have been synthesized and characterized by single X-ray analyses, thermal gravimetry, and adsorption measurements.

Uemura, Kazuhiro, E-mail: k_uemura@gifu-u.ac.j [Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube-shi, Yamaguchi 755-8611 (Japan); Onishi, Fumiaki; Yamasaki, Yukari; Kita, Hidetoshi [Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube-shi, Yamaguchi 755-8611 (Japan)

2009-10-15

358

Two new pyridine-2,3-dicarboxylate coordination polymers prepared from zerovalent metal precursor: Syntheses, luminescent and magnetic properties  

SciTech Connect

Two new K{sup +}/Cu(II) and Zn(II) coordination polymers with pyridine-2,3-dicarboxylate (pydc), (K{sub 2}[Cu(?-pydc){sub 2}]·3H{sub 2}O){sub n} (1) and ([Zn(µ-pydc)(H{sub 2}O)(4-mim)]·H{sub 2}O){sub n} (2) (4-mim=4-methylimidazole) have been synthesized from zerovalent metal and characterized by IR, EPR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. In the sandwiched 3D anionic framework of 1, pydc ligands exhibit hexadentate coordination; tridentate coordination bond with Cu(II) and tridentate ionic interaction with K{sup +} ions. (K{sub 2}[Cu(?-pydc){sub 2}]·3H{sub 2}O){sub n} shows a rare topology consists of three dimensional (3,4,5)-connected network with the point symbol of (4{sup 2}.6){sub 2}(4{sup 2}.8{sup 4})(4{sup 3}.6.8{sup 6}){sub 2}. The distorted square pyramidal geometry of 2 is completed with an nitrogen atom from 4-mim and aqua ligand to form a 1D polynuclear structure. The hydrogen bonds link the 1D chains into 3D architecture. The temperature dependent magnetic property of complex 1 has been studied. Complex 2 exhibits unusual yellow luminescence in the solid state at room temperature. - Graphical abstract: Two new K{sup +}/Cu(II) and Zn(II) coordination polymers with pyridine-2,3-dicarboxylate (pydc), (K{sub 2}[Cu(?-pydc){sub 2}]·3H{sub 2}O){sub n} (1) and ([Zn(µ-pydc)(H{sub 2}O)(4-mim)]·H{sub 2}O){sub n} (2) (4-mim=4-methylimidazole) have been synthesized from zerovalent metal and characterized by IR, EPR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The water soluble (K{sub 2}[Cu(?-pydc){sub 2}]·3H{sub 2}O){sub n} shows three dimensional a rare 3,4,5-connected network with the point symbol of (4{sup 2}.6){sub 2}(4{sup 2}.8{sup 4})(4{sup 3}.6.8{sup 6}){sub 2}. The temperature dependent magnetic property of complex 1 has been studied. Complex 2 exhibits unusual yellow luminescence in the solid state at room temperature. Display Omitted - Highlights: • Water-soluble (K{sub 2}[Cu(?-pydc){sub 2}]·3H{sub 2}O){sub n} has synthesized. • Zerovalent metal precursors are utilized. • The temperature dependent magnetic properties have been studied.

Semerci, Fatih [Department of Chemistry, Faculty of Arts and Sciences, Eski?ehir Osmangazi University, 26480 Eski?ehir (Turkey); Department of Chemistry, Faculty of Arts and Sciences, K?rklareli University, K?rklareli (Turkey); Ye?ilel, Okan Zafer, E-mail: yesilel@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eski?ehir Osmangazi University, 26480 Eski?ehir (Turkey); Soylu, Mustafa Serkan [Department of Physics, Faculty of Arts and Sciences, Giresun University, Giresun (Turkey); Yerli, Yusuf [Department of Physics, Gebze Institute of Technology, 41400 Gebze (Turkey); Dal, Hakan [Department of Chemistry, Faculty of Sciences, Anadolu University, Eski?ehir (Turkey)

2014-02-15

359

Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers  

NASA Astrophysics Data System (ADS)

The organic ligand 2,5-piperazinedione-1,4-diacetic acid (H2PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P21/c monoclinic system as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric analysis. Two new coordination networks based on lanthanide ions were obtained with this ligand using hydrothermal reaction. In addition to single-crystal X-ray diffraction, the compounds were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis. Single-crystal XRD showed that the compounds are isostructural, crystallizing in P21/n monoclinic system with chemical formula [Ln(PDA)1.5(H2O)](H2O)3 (Ln=Gd3+(1) and Eu3+(2)).The luminescence properties of both compounds were studied. In the compound (1), a broad emission band was observed at 479 nm, redshifted by 70 nm in comparison of the free ligand. In (2), the typical f-f transition was observed with a maximum peak at 618 nm, related with the red emission of the europium ions. Computational methods were performed to simulate the crystal structure of (2). The theoretical calculations of the intensity parameters are in good agreement with the experimental values.

da Silva, Fausthon Fred; de Oliveira, Carlos Alberto Fernandes; Falcão, Eduardo Henrique Lago; Gatto, Claudia Cristina; da Costa, Nivan Bezerra; Freire, Ricardo Oliveira; Chojnacki, Jaros?aw; Alves Júnior, Severino

2013-11-01

360

Uranyl sensitization of samarium(III) luminescence in a two-dimensional coordination polymer.  

PubMed

Heterometallic carboxyphosphonates UO(2)(2+)/Ln(3+) have been prepared from the hydrothermal reaction of uranyl nitrate, lanthanide nitrate (Ln = Sm, Tb, Er, Yb), and phosphonoacetic acid (H(3)PPA). Compound 1, (UO(2))(2)(PPA)(HPPA)(2)Sm(H(2)O)·2H(2)O (1) adopts a two-dimensional structure in which the UO(2)(2+) metal ions bind exclusively to the phosphonate moiety, whereas the Ln(3+) ions are coordinated by both phosphonate and carboxylate functionalities. Luminescence studies of 1 show very bright visible and near-IR samarium(III)-centered emission upon direct excitation of the uranyl moiety. The Sm(3+) emissive state exhibits a double-exponential decay with lifetimes of 67.2 ± 6.5 and 9.0 ± 1.3 ?s as measured at 594 nm, after excitation at both 365 and 420 nm. No emission is observed in the region typical of the uranyl cation, indicating that all energy is either transferred to the Sm(3+) center or lost to nonradiative processes. Herein we report the synthesis, crystal structure, and luminescent behavior of 1, as well as those of the isostructural terbium, erbium, and ytterbium analogues. PMID:22171660

Knope, Karah E; de Lill, Daniel T; Rowland, Clare E; Cantos, Paula M; de Bettencourt-Dias, Ana; Cahill, Christopher L

2012-01-01

361

Influence of the co-ligand on the magnetic and relaxation properties of layered cobalt(II) thiocyanato coordination polymers.  

PubMed

Reaction of Co(NCS)2 with 1,2-bis(4-pyridyl)-ethane (bpa) leads to the formation of [Co(NCS)2(bpa)2]n, which, on heating, transforms into the new layered coordination polymer [Co(NCS)2(bpa)]n. This compound can also be prepared in solution, but because no reasonable single crystals are available, its crystal structure was determined from X-ray powder data from scratch. In the crystal structure of [Co(NCS)2(bpa)]n, the cobalt(II) cations are coordinated by two S-bonded and two N-bonded thiocyanato anions and two N atoms of the bpa co-ligands in a distorted octahedral geometry. The cobalt(II) cations are linked into chains by pairs of ?-1,3 bridging thiocyanato anions. These chains are further connected into layers by the 1,2-bis(4-pyridyl)-ethane ligand. The compound was magnetically characterized, and, for comparative purposes, the complementary magnetic study of a known and very similar compound, [Co(NCS)2(bpe)]n (bpe = 1,2-bis(4-pyridyl)-ethylene), was also undertaken. The compounds differ in their interchain interactions, which are antiferromagnetic but significantly greater for [Co(NCS)2(bpe)]n. Magnetic measurements indicate that [Co(NCS)2(bpa)]n is a canted antiferromagnet with Néel temperature TN = 3.1 K and that Co(NCS)2(bpe) is an antiferromagnet with TN = 4.0 K. Both compounds show a metamagnetic transition with a critical field HC ? 40 Oe and ? 400 Oe, respectively. Magnetic relaxations were studied by means of dc and ac methods and analyzed using the Argand diagrams. Except for the thermally activated single chain and domain wall relaxations observed for both compounds, temperature-independent slow relaxations were observed for [Co(NCS)2(bpa)]n. PMID:25080077

Wöhlert, Susanne; Tomkowicz, Zbigniew; Rams, Micha?; Ebbinghaus, Stefan G; Fink, Lothar; Schmidt, Martin U; Näther, Christian

2014-08-18

362

A novel polythreading Ag(I) coordination polymer with blue photoluminescence  

SciTech Connect

One new compound, [Ag(p-bix)]{sub 3}[Ag(Hbtc){sub 2}]·2H{sub 2}O (H{sub 3}btc=1,2,4-benzenetricarboxylate, p-bix=1,4-bis(imidazol-1-ylmethyl)-benzene), has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, PXRD, luminescent analysis, and single-crystal X-ray diffraction. X-ray structural analysis revealed that 0-D unit [Ag(Hbtc){sub 2}]{sup 3?} and two kinds of 1-D linear chain [Ag(p-bix)]{sub ?}{sup +}, can be found within the crystal structure. The combination of 0-D [Ag(Hbtc){sub 2}]{sup 3?} unit and 1-D undulated chain [Ag1(p{sub 1}-bix)]{sub ?}{sup +} through weak Ag–O bond gave rise to 2-D anionic supramolecular doublelayer. Then the grids of the 2-D layer are threaded by 1-D linear cationic chain [Ag2(p{sub 2}-bix)]{sub ?}{sup +} to generate entangled 3-D architecture with unusual poly(pseudo-rotaxane)-type arrangements. Luminescent properties of the title complex were also studied in this paper. - Graphical abstract: Novel 3D polythreading supramolecular architecture was constructed, in which 1D linear cationic chains [Ag(p{sub 2}-bix)]{sub ?}{sup +} threaded into the grid of weak Ag–O bonded anionic 2D sheet. Highlights: ? Novel 1D{sup +}+2D{sup ?}?3D polythreading coordination complex was reported. ? Diverse conformations of p-bix result in different 1D [Ag(p-bix)]{sub ?}{sup +} chains. ? The title complex displayed blue photoluminescence at room temperature.

Duan, Xian-Ying, E-mail: dxynumber@163.com [State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Institute of Chemistry, Henan Academy of Sciences, Zhengzhou 450002 (China); Yao, Jing; Lu, Chang-Sheng [State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Meng, Qing-Jin, E-mail: mengqj@nju.edu.cn [State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China)

2013-04-15

363

THz time domain spectroscopy of low-frequency vibrations in a quasi-one-dimensional system  

NASA Astrophysics Data System (ADS)

The mixed-valence halide-bridged transition metal linear chain (MX) complexes are prototypical quasi-one-dimensional systems, with a charge density wave ground state and localized electronic excitations analogous to those of conjugated organic polymers. In this work, we present studies of the low-frequency infrared-active vibrational modes of the MX complex [Pt(en)2][Pt(en)2I2](PF6)4 (en = ethylenediamine, C2H8N2) in the frequency range 0.3 - 3 THz using terahertz time-domain spectroscopic techniques. Distinct polarization-dependent complex refractive indices are observed in single-crystal samples of this highly anisotropic material. The measurements reveal a strong absorption at a frequency of 2.24 THz (75 cm-1) polarized along the chain axis, which we assign to the infrared-active ?3 vibrational mode, involving relative motion of the mixed-valence ions in the charge density wave structure. This work is supported by NSF grant DMR-0706407.

Bandyopadhyay, A.; Dexheimer, S. L.

2008-03-01

364

Syntheses, crystal structures, and water adsorption behaviors of jungle-gym-type porous coordination polymers containing nitro moieties  

NASA Astrophysics Data System (ADS)

NO 2 containing dicarboxylate bridging ligands, nitroterephthalate (bdc-NO 2) and 2,5-dinitroterephthalate (bdc-(NO 2) 2), afford porous coordination polymers, {[Zn 2(bdc-NO 2) 2(dabco)]· solvents} n ( 2? solvents) and {[Zn 2(bdc-(NO 2) 2) 2(dabco)]· solvents} n ( 3? solvents). Both compounds form jungle-gym-type regularities, where a 2D square grid composed of dinuclear Zn 2 units and dicarboxylate ligands is bridged by dabco molecules to extend the 2D layers into a 3D structure. In 2? solvents and 3? solvents, a rectangle pore surrounded by eight Zn 2 corners contains two and four NO 2 moieties, respectively. Thermal gravimetry (TG) and X-ray powder diffraction (XRPD) measurements reveal that both compounds maintain the frameworks regularities without guest molecules and with solvents such as MeOH, EtOH, i-PrOH, and Me 2CO. Adsorption measurements reveal that dried 2 and 3 adsorb H 2O molecules to be {[Zn 2(bdc-NO 2) 2(dabco)]·4H 2O} n ( 2?4H 2O) and {[Zn 2(bdc-(NO 2) 2) 2(dabco)]·6H 2O} n ( 3?6H 2O), showing the pore hydrophilicity enhancement caused by NO 2 group introduction.

Uemura, Kazuhiro; Onishi, Fumiaki; Yamasaki, Yukari; Kita, Hidetoshi

2009-10-01

365

Self-assembled nanoscale coordination polymers carrying oxaliplatin and gemcitabine for synergistic combination therapy of pancreatic cancer.  

PubMed

Gemcitabine has long been the standard of care for treating pancreatic ductal adenocarcinoma (PDAC), despite its poor pharmacokinetics/dynamics and rapid development of drug resistance. In this study, we have developed a novel nanoparticle platform based on nanoscale coordination polymer-1 (NCP-1) for simultaneous delivery of two chemotherapeutics, oxaliplatin and gemcitabine monophosphate (GMP), at 30wt.% and 12wt.% drug loadings, respectively. A strong synergistic therapeutic effect of oxaliplatin and GMP was observed in vitro against AsPc-1 and BxPc-3 pancreatic cancer cells. NCP-1 particles effectively avoid uptake by the mononuclear phagocyte system (MPS) in vivo with a long blood circulation half-life of 10.1±3.3h, and potently inhibit tumor growth when compared to NCP particles carrying oxaliplatin or GMP alone. Our findings demonstrate NCP-1 as a novel nanocarrier for the co-delivery of two chemotherapeutics that have distinctive mechanisms of action to simultaneously disrupt multiple anticancer pathways with maximal therapeutic efficacy and minimal side effects. PMID:25620067

Poon, Christopher; He, Chunbai; Liu, Demin; Lu, Kuangda; Lin, Wenbin

2015-03-10

366

Synthesis, crystal structures, luminescence and catalytic properties of two d(10) metal coordination polymers constructed from mixed ligands.  

PubMed

Two new coordination polymers [Cd(bmb)(hmph)]n (1), {[Ag(bmb)]·H2btc}n (2) (bmb=1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H2hmph=homophthalic acid, H3btc=1,3,5-benzenetetracarboxylic acid) were synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction methods, IR spectroscopy, TGA, XRPD and elemental analysis. Complex 1 features a 3D threefold interpenetrating dia array with a 4-connected 6(6) topology. Complex 2 shows a 1D helix chain structure connected by L1 ligands, which is finally extended into a rarely 2D 4L2 supramolecular network via C-H?O hydrogen bond interactions. In addition, the luminescence and catalytic properties of the two complexes for the degradation of the methyl orange azo dye in a Fenton-like process were presented. The degradation efficiency of the methyl orange azo dye for 1 and 2 are 56% and 96%, respectively. PMID:25576941

Wang, Xiao-Xiao; Zhang, Ming-Xi; Yu, Baoyi; Van Hecke, Kristof; Cui, Guang-Hua

2015-03-15

367

Syntheses, structures and properties of three cobalt coordination polymers based on flexible bis(triazole) and 5-nitroisophthalate coligands  

NASA Astrophysics Data System (ADS)

Three coordination polymers {[Co(bte)(NO2-1,3-bdc)(H2O)]?H2O}n (1), {[Co(btp)(NO2-1,3-bdc)(H2O)]?2H2O}n (2) and {[Co2(btb)2(NO2-1,3-bdc)2]?2H2O}n (3) were synthesized by the different spacer lengths and conformational flexibilities bte, btp, btb and the rigid NO2-1,3-bdc. 1 forms an independent 1D MONT and a (1D ? 2D) interdigitated array. In 2, two identical undulated (4,4) networks are parallel stacking to give a double-layer. In 3, the btb ligands connect the [Co2(NO2-1,3-bdc)2]n ladders to construct an unusual 3D network with point symbol 46?67?82 based on [Co2(COO)2] unit. The thermal stability and the UV-vis spectra of 1, 2 and 3 were investigated.

Chen, Qian; Zhu, Xia; Ding, Jian-Gang; Li, Bao-Long; Li, Hai-Yan

2013-04-01

368

Silver Coordination Polymers for Prevention of Implant Infection: Thiol Interaction, Impact on Respiratory Chain Enzymes, and Hydroxyl Radical Induction? †  

PubMed Central

Prosthetic joint replacements are used increasingly to alleviate pain and improve mobility of the progressively older and more obese population. Implant infection occurs in about 5% of patients and entails significant morbidity and high social costs. It is most often caused by staphylococci, which are introduced perioperatively. They are a source of prolonged seeding and difficult to treat due to antibiotic resistance; therefore, infection prevention by prosthesis coating with nonantibiotic-type anti-infective substances is indicated. A renewed interest in topically used silver has fostered development of silver nanoparticles, which, however, present a potential health hazard. Here we present new silver coordination polymer networks with tailored physical and chemical properties as nanostructured coatings on metallic implant substrates. These compounds exhibited strong biofilm sugar-independent bactericidal activity on in vitro-grown biofilms and prevented murine Staphylococcus epidermidis implant infection in vivo with slow release of silver ions and limited transient leukocyte cytotoxicity. Furthermore, we describe the biochemical and molecular mechanisms of silver ion action by gene screening and by targeting cell metabolism of S. epidermidis at different levels. We demonstrate that silver ions inactivate enzymes by binding sulfhydryl (thiol) groups in amino acids and promote the release of iron with subsequent hydroxyl radical formation by an indirect mechanism likely mediated by reactive oxygen species. This is the first report investigating the global metabolic effects of silver in the context of a therapeutic application. We anticipate that the compounds presented here open a new treatment field with a high medical impact. PMID:20660682

Gordon, Oliver; Vig Slenters, Tünde; Brunetto, Priscilla S.; Villaruz, Amer E.; Sturdevant, Daniel E.; Otto, Michael; Landmann, Regine; Fromm, Katharina M.

2010-01-01

369

Solvent induced rapid modulation of micro/nano structures of metal carboxylates coordination polymers: mechanism and morphology dependent magnetism.  

PubMed

Rational modulation of morphology is very important for functional coordination polymers (CPs) micro/nanostructures, and new strategies are still desired to achieve this challenging target. Herein, organic solvents have been established as the capping agents for rapid modulating the growth of metal-carboxylates CPs in organic solvent/water mixtures at ambient conditions. Co-3,5-pyridinedicarboxylate (pydc) CPs was studied here as the example. During the reaction, the organic solvents exhibited three types of modulation effect: anisotropic growth, anisotropic growth/formation of new crystalline phase and the formation of new crystalline phase solely, which was due to the variation of their binding ability with metal cations. The following study revealed that the binding ability was critically affected by their functional groups and molecular size. Moreover, their modulation effect could be finely tuned by changing volume ratios of solvent mixtures. Furthermore, they could be applied for modulating other metal-carboxylates CPs: Co-1,3,5-benzenetricarboxylic (BTC), Zn-pydc and Eu-pydc etc. Additionally, the as-prepared Co-pydc CPs showed a fascinating morphology-dependent antiferromagnetic behavior. PMID:25113225

Liu, Kun; Shen, Zhu-Rui; Li, Yue; Han, Song-De; Hu, Tong-Liang; Zhang, Da-Shuai; Bu, Xian-He; Ruan, Wen-Juan

2014-01-01

370

Syntheses, structures, molecular and cationic recognitions and catalytic properties of two lanthanide coordination polymers based on a flexible tricarboxylate  

NASA Astrophysics Data System (ADS)

Two lanthanide coordination polymers, namely, {[La(TTTA)(H2O)2]·2H2O}n (La-TTTA) and [Nd(TTTA)(H2O)2]·2H2O}n (Nd-TTTA) have been hydrothermally synthesized through the reaction of lanthanide ions (La3+ and Nd3+) with the flexible tripodal ligand 2,2?,2?-[1,3,5-triazine-2,4,6-triyltris(thio)]tris-acetic acid (H3TTTA). La-TTTA and Nd-TTTA are isostructural and both show three dimensional structures. La-TTTA and Nd-TTTA show good recognition of amine molecules via quenching the luminescent intensities in amines emulsions. They can also recognize Fe3+, Cu2+, Mg2+, Cr3+ and Co2+ ions with the quenching the peak around 361 nm when the compounds immersed in ionic solutions. The two compounds act as efficient Lewis acid catalysts for the cyanosilylation of benzaldehyde and derivatives in high yields shortly due to the strong Lewis acidity and the possible open sites of the lanthanide ions.

Zhu, Yu; Wang, Yan-Mei; Xu, Ji; Liu, Pan; Weththasinha, H. A. B. M. D.; Wu, Yun-Long; Lu, Xiao-Qing; Xie, Ji-Min

2014-11-01

371

Self-assembled nanoscale coordination polymers carrying siRNAs and cisplatin for effective treatment of resistant ovarian cancer.  

PubMed

Resistance to the chemotherapeutic agent cisplatin is a major limitation for the successful treatment of many cancers. Development of novel strategies to overcome intrinsic and acquired resistance to chemotherapy is of critical importance to effective treatment of ovarian cancer and other types of cancers. We have sought to re-sensitize resistant ovarian cancer cells to chemotherapy by co-delivering chemotherapeutics and pooled siRNAs targeting multi-drug resistance (MDR) genes using self-assembled nanoscale coordination polymers (NCPs). In this work, NCP-1 particles with trigger release properties were first constructed by linking cisplatin prodrug-based bisphosphonate bridging ligands with Zn(2+) metal-connecting points and then coated with a cationic lipid layer, followed by the adsorption of pooled siRNAs targeting three MDR genes including survivin, Bcl-2, and P-glycoprotein via electrostatic interactions. The resulting NCP-1/siRNA particles promoted cellular uptake of cisplatin and siRNA and enabled efficient endosomal escape in cisplatin-resistant ovarian cancer cells. By down-regulating the expression of MDR genes, NCP-1/siRNAs enhanced the chemotherapeutic efficacy as indicated by cell viability assay, DNA ladder, and flow cytometry. Local administration of NCP-1/siRNAs effectively reduced tumor sizes of cisplatin-resistant SKOV-3 subcutaneous xenografts. This work shows that the NCP-1/siRNA platform holds great promise in enhancing chemotherapeutic efficacy for the effective treatment of drug-resistant cancers. PMID:25315138

He, Chunbai; Liu, Demin; Lin, Wenbin

2015-01-01

372

Two novel indium coordination polymers derived from 2,6-pyridinedicarboxylate ligand: Syntheses, structures and photoluminescent properties  

NASA Astrophysics Data System (ADS)

Two indium coordination polymers (CPs) with different structures InCl(2,6-pdc)(H2O) (1) and In2Cl4(2,6-pdc)(4,4?-bipy)2 (2) were synthesized by the reactions of InCl3 with 2,6-pyridinedicarboxylic acid (2,6-H2pdc) and 4,4?-bipyridine (4,4?-bipy) ligands. Compound 1 features a two dimensional (2D) network with the rhombic windows constructed from novel [In2O6(H2O)2Cl2(2,6-pdc)2] dimeric building units and 2,6-pdc2- ligands. Compound 2 possesses a 2D layer structure which is accomplished by connecting the wavy chains to the distorted 4,4?-bipy ligands. The different structures of 1 and 2 show the predominant influence of chlorine atoms and organic ligands. In addition, non-classical hydrogen-bond (C-H⋯Cl) interactions also play an important role in the formation of supramolecular architectures, for instance, to link 2D entities to 3D frameworks. These new In(III) CPs show intense fluorescence emission with long lifetimes in the solid state at room temperature.

Yang, Lu; Xu, Jianing; Xia, Jing; Liu, Yunling; Wang, Li; Fan, Yong

2014-10-01

373

Nanorods of a new metal-biomolecule coordination polymer showing novel bidirectional electrocatalytic activity and excellent performance in electrochemical sensing.  

PubMed

Metal organic coordination polymers (CPs), as most attractive multifunctional materials, have been studied extensively in many fields. However, metal-biomolecule CPs and CPs' electrochemical properties and applications were studied much less. We focus on this topic aiming at electrochemical biosensors with excellent performance and high biocompatibility. A new nanoscaled metal-biomolecule CP, Mn-tyr, containing manganese and tyrosine, was synthesized hydrothermally and characterized by various techniques, including XRD, TEM, EDS, EDX mapping, elemental analysis, XPS, and IR. Electrode modified with Mn-tyr showed novel bidirectional electrocatalytic ability toward both reduction and oxidation of H2O2, which might be due to Mn. With the assistance of CNTs, the sensing performance of Mn-tyr/CNTs/GCE was improved to a much higher level, with high sensitivity of 543mAmol(-1)Lcm(-2) in linear range of 1.00×10(-6)-1.02×10(-4)molL(-1), and detection limit of 3.8×10(-7)molL(-1). Mn-tyr/CNTs/GCE also showed fast response, high selectivity, high steadiness and reproducibility. The excellent performance implies that the metal-biomolecule CPs are promising candidates for using in enzyme-free electrochemical biosensing. PMID:25037318

Yang, Jiao; Zhou, Bo; Yao, Jie; Jiang, Xiao-Qing

2015-05-15

374

Rectangular Coordination Polymer Nanoplates: Large-Scale, Rapid Synthesis and Their Application as a Fluorescent Sensing Platform for DNA Detection  

PubMed Central

In this paper, we report on the large-scale, rapid synthesis of uniform rectangular coordination polymer nanoplates (RCPNs) assembled from Cu(II) and 4,4?-bipyridine for the first time. We further demonstrate that such RCPNs can be used as a very effective fluorescent sensing platform for multiple DNA detection with a detection limit as low as 30 pM and a high selectivity down to single-base mismatch. The DNA detection is accomplished by the following two steps: (1) RCPN binds dye-labeled single-stranded DNA (ssDNA) probe, which brings dye and RCPN into close proximity, leading to fluorescence quenching; (2) Specific hybridization of the probe with its target generates a double-stranded DNA (dsDNA) which detaches from RCPN, leading to fluorescence recovery. It suggests that this sensing system can well discriminate complementary and mismatched DNA sequences. The exact mechanism of fluorescence quenching involved is elucidated experimentally and its use in a human blood serum system is also demonstrated successfully. PMID:22279589

Zhang, Yingwei; Luo, Yonglan; Tian, Jingqi; Asiri, Abdullah M.; Al-Youbi, Abdulrahman O.; Sun, Xuping

2012-01-01

375

Neutral and anionic duality of 1,2,4-triazole ?-amino acid scaffold in 1D coordination polymers  

NASA Astrophysics Data System (ADS)

A tiny supramolecular synthon, 4H-1,2,4-triazol-4-yl acetic acid (HGlytrz) which is bifunctional by design having an electronic asymmetry and conformational flexibility has been introduced to synthesize iron(II) complexes. Having 1,2,4-triazole or carboxylic extremities on the same framework HGlytrz could display dual functionality by acting as a neutral as well as anionic ligand based on the possibility of deprotonation of carboxylic group. Four new iron(II) HGlytrz complexes with ClO4- ( 1), NO3- ( 2), BF4- ( 3) and CF3SO3- ( 4) anions were prepared. Formulation of their composition which is complicated due to ligand deprotonation is discussed. Unlike its ester protected counterpart ethyl-4H-1,2,4-triazol-4-yl-acetate ( ?Glytrz) which show hysteretic room temperature spin crossover, 1- 4 remain in the high-spin state as revealed by 57Mössbauer spectroscopy. Prospects of such 1D coordination polymers with dangling unbounded carboxylic entities in the realm of self-assembled monolayer (SAM) are discussed.

Naik, Anil D.; Dîrtu, Marinela M.; Garcia, Yann

2012-03-01

376

Porous coordination polymers of diverse topologies based on a twisted tetrapyridylbiaryl: application as nucleophilic catalysts for acetylation of phenols.  

PubMed

Porous coordination polymers (CPs) with partially uncoordinated pyridyl rings based on rationally designed polypyridyl linkers are appealing from the point of view of their application as nucleophilic catalysts. A D2d -symmetric tetradentate organic linker L, that is, 2,2',6,6'-tetramethoxy-3,3',5,5'-tetrakis(4-pyridyl)biphenyl, was designed and synthesized for metal-assisted self-assembly aimed at porous CPs. Depending on the nature of the metal ion and the counter anion, the ligand L is found to function as a 3- or 4-connecting building block leading to porous CPs of diverse topologies. The reaction of L with Zn(NO3 )2 and Cd(NO3 )2 yields porous 2?D CPs of "fes" topology, in which the tetrapyridyl linker L serves as a 3-connecting unit with its free pyridyl rings well exposed into the pores. The functional utility of these porous CPs containing uncoordinated pyridyl rings is demonstrated by employing them as efficient heterogeneous nucleophilic catalysts for acetylation of a number of phenols with varying electronic properties and reactivities. PMID:25430673

Seth, Saona; Venugopalan, Paloth; Moorthy, Jarugu Narasimha

2015-01-26

377

Solvent induced rapid modulation of micro/nano structures of metal carboxylates coordination polymers: mechanism and morphology dependent magnetism  

PubMed Central

Rational modulation of morphology is very important for functional coordination polymers (CPs) micro/nanostructures, and new strategies are still desired to achieve this challenging target. Herein, organic solvents have been established as the capping agents for rapid modulating the growth of metal-carboxylates CPs in organic solvent/water mixtures at ambient conditions. Co-3,5-pyridinedicarboxylate (pydc) CPs was studied here as the example. During the reaction, the organic solvents exhibited three types of modulation effect: anisotropic growth, anisotropic growth/formation of new crystalline phase and the formation of new crystalline phase solely, which was due to the variation of their binding ability with metal cations. The following study revealed that the binding ability was critically affected by their functional groups and molecular size. Moreover, their modulation effect could be finely tuned by changing volume ratios of solvent mixtures. Furthermore, they could be applied for modulating other metal-carboxylates CPs: Co-1,3,5-benzenetricarboxylic (BTC), Zn-pydc and Eu-pydc etc. Additionally, the as-prepared Co-pydc CPs showed a fascinating morphology-dependent antiferromagnetic behavior. PMID:25113225

Liu, Kun; Shen, Zhu-Rui; Li, Yue; Han, Song-De; Hu, Tong-Liang; Zhang, Da-Shuai; Bu, Xian-He; Ruan, Wen-Juan

2014-01-01

378

Exact solution of the one-dimensional super-symmetric t-J model with unparallel boundary fields  

NASA Astrophysics Data System (ADS)

The exact solution of the one-dimensional super-symmetric t-J model under generic integrable boundary conditions is obtained via the Bethe ansatz methods. With the coordinate Bethe ansatz, the corresponding R-matrix and K-matrices are derived for the second eigenvalue problem associated with spin degrees of freedom. It is found that the second eigenvalue problem can be transformed into that of the transfer matrix of the inhomogeneous XXX spin chain, which allows us to obtain the spectrum of the Hamiltonian and the associated Bethe ansatz equations by the off-diagonal Bethe ansatz method.

Zhang, Xin; Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

2014-04-01

379

Self-Assembly, Structures, and Magnetic Properties of Ladder-Like Copper(II) Coordination Polymers  

NASA Astrophysics Data System (ADS)

Two novel ladder-like copper(II) compounds, [Cu2(histamine)2(C2O4)(ClO4)2] (1) and [Cu2(histamine)2(C2O4)(H2O)2(NO3)2] (2), are prepared. Compound 1 crystallizes in the triclinic space group Poverline1, with a=7.450(4) Å, b=7.519(7) Å, c=9.646(5) Å, ?=85.78(7)°, ?=88.60(4)°, ?=76.78(7)°, V=524.5(6) Å3, and Z=1 with R=0.0789 (all data). In 1, the dinuclear units of [Cu2(histamine)2(C2O4)]2+ are linked together by the perchlorate anions to form a ladder-like chain. The chains interact each other by the ?-? stacking interactions via the imidazole groups. Compound 2 crystallizes in the triclinic space group Poverline1, with a=7.579(2) Å, b=8.133(1) Å, c=9.161(3) Å, ?=77.06(2)°, ?=89.23(2)°, ?=82.54(1)°, V=545.6(2) Å3, and Z=1 with R=0.0751 (all data). In 2, each dinuclear unit [Cu2(histamine)2(C2O4)]2+ is coordinated with a nitrate anion and a water molecule, and they are held together by the hydrogen bonding interactions to form a ladder-like chain. The magnetic susceptibility data of 1 and 2 measured in 2-300 K provide the magnetic parameters, g=2.08, J=-166 cm-1, J?=6.46 cm-1, ?=0.0026, N?=155×10-6 cm3 mol-1, and R=1.03×10-3 (g=2.05, J=-162 cm-1, J?=10.5 cm-1, ?=0.0029, and R=2.95×10-3 with the fixed value of N?=120×10-6 cm3 mol-1) for 1 and g=2.00, J=-158 cm-1, J?=26.5 cm-1, ?=0.0020, N?=136×10-6 cm3 mol-1, and R=7.31×10-4 (g=2.01, J=-157 cm-1, J?=25.0 cm-1, ?=0.0021, and R=1.32×10-3 with the fixed value of N?=120×10-6 cm3 mol-1) for 2. These indicate that very strong antiferromagnetic interactions occur along the rungs of the ladder via the oxalate bridge and weak ferromagnetic interactions along the chains.

Min, Kil Sik; Suh, Myunghyun Paik

2000-06-01

380

Hydrogen adsorption in a nickel based coordination polymer with open metal sites in the cylindrical cavities of the desolvated framework.  

PubMed

The solvent contained within the cylindrical one-dimensional pores of the novel three-dimensional metal organic framework Ni2(dhtp)(H2O)2.8H2O can be removed without decomposition of the network, allowing gas storage within the cavities. PMID:16491175

Dietzel, Pascal D C; Panella, Barbara; Hirscher, Michael; Blom, Richard; Fjellvåg, Helmer

2006-03-01

381

Ultrashort pulse laser one-dimensional range profile of a cone  

Microsoft Academic Search

In this paper, ultra-short pulse laser one-dimensional range profile theory and simulation are investigated. Ultra-short pulse laser one-dimensional range profile simulation is studied on the basis of beam scattering by a rough object, pulse wave scattering theory, and the radar equation. An equation for an ultra-short pulse laser one-dimensional range profile is calculated. As examples, range profile simulations are calculated

Yanhui Li; Zhensen Wu; Yanjun Gong

2011-01-01

382

A one-dimensional organic-inorganic hybrid based on the bimolecular {l_brace}[Cu(en){sub 2}]{sub 2}[Cu{sub 2}Si{sub 2}W{sub 22}O{sub 78}]{r_brace}{sup 8-} polyoxometalate  

SciTech Connect

A one-dimensional coordination polymer [Cu(en){sub 2}]{sub 2}[Cu(en){sub 2}(H{sub 2}O)]{sub 2}{l_brace}[Cu(en){sub 2}]{sub 2}[Cu{sub 2}Si{sub 2}W{sub 22}O{sub 78}]{r_brace}.4.5H{sub 2}O (en=ethylenediamine), which represents the first example of one-dimensional organic-inorganic hybrid based on the bimolecular Keggin polyoxometalates {l_brace}[Cu(en){sub 2}]{sub 2}[Cu{sub 2}Si{sub 2}W{sub 22}O{sub 78}]{r_brace}{sup 8-} has been hydrothermally synthesized and characterized by elemental analyses, IR, TG and single crystal X-ray diffraction. Crystal data: C{sub 24}H{sub 85}Cu{sub 8}N{sub 24}O{sub 84.5}Si{sub 2}W{sub 22}, monoclinic, P2{sub 1}/c, a=18.8126(3), b=23.0896(4), c=26.0711(4) A, {beta}=96.3790(10){sup o}, V=11254.5(3) A{sup 3}, T=293(2) K; Z=4, {mu}=23.983 mm{sup -1}, R {sub 1}=0.0628, wR {sub 2}=0.1210 [I>2{sigma}], R {sub 1}=0.0854, wR {sub 2}=0.1285 (all data ). - Graphical abstract: A one-dimensional coordination polymer which represents the first example of 1D organic-inorganic hybrid based on the bimolecular Keggin POMs {l_brace}[Cu(en){sub 2}]{sub 2}[Cu{sub 2}Si{sub 2}W{sub 22}O{sub 78}]{r_brace}{sup 8-} has been hydrothermally synthesized and characterized.

Wang Jingping [Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001 (China); Du Xiaodi [Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001 (China); Niu Jingyang [Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001 (China)], E-mail: jyniu@henu.edu.cn

2007-04-15

383

One-Dimensional Conducting Polymer Nanostructures for Chemical and Biological Sensor Applications  

E-print Network

of top-down and bottom-up approaches significantly improvedtop-down “photolithography” and bottom-up “electrodeposition” approachestop-down photolithography and bottom-up electrodeposition approaches,

Chartuprayoon, Nicha

2012-01-01

384

Polymers.  

ERIC Educational Resources Information Center

Presents an open-ended experiment which has students exploring polymer chemistry and reverse osmosis. This activity involves construction of a polymer membrane, use of it in a simple osmosis experiment, and application of its principles in solving a science-technology-society problem. (ML)

Tucker, David C.

1986-01-01

385

Utilization of a ligand containing 2,2'-bipyridyl and tetrazolate groups to construct a 2D Co(II) coordination polymer: spin canting and metamagnetism.  

PubMed

The use of anions of 6,6'-bis(1H-tetrazol-5-yl)-2,2'-bipyridine (H2btzbp) as chelating ligands in preparing a coordination polymer is described. The synthesis, X-ray crystal structure and magnetic properties of a new Co(II) coordination polymer, [Co(btzbp)]n (1), are reported. The in situ [2 + 3] cycloaddition reaction of 6,6'-dicyano-2,2'-bipyridine with sodium azide in the presence of Co(ClO4)2 under hydrothermal conditions afforded compound 1. Structural characterization revealed that 1 features a distorted two-dimensional (2D) grid layer generated by both tetrazolate and 2,2'-bipyridyl bridges of the btzbp(2-) ligand. Variable temperature and field magnetic susceptibility measurements indicate that compound 1 exhibits spin canting with T(N) = 4.0 K and metamagnetism with H(c) = 300 G. PMID:25200595

Tsai, Jia-Dong; Yang, Chen-I

2014-11-01

386

Fabrication, Device Assembly, and Application of One-Dimensional Chalcogenides Nanostructures.  

E-print Network

??Nanotechnology has received a tremendous amount of research interests ever since the first discovery of carbon nanotubes. One-dimensional nanostructures, such as nanorods, nanowires, nanobelts as… (more)

Kum, Maxwell C.

2009-01-01

387

Three dimensional nano-assemblies of noble metal nanoparticle-infinite coordination polymers as specific oxidase mimetics for degradation of methylene blue without adding any cosubstrate.  

PubMed

Novel three-dimensional (3D) nano-assemblies of noble metal nanoparticle (NP)-infinite coordination polymers (ICPs) are conveniently fabricated through the infiltration of HAuCl4 into hollow Au@Ag@ICPs core-shell nanostructures and its replacement reaction with Au@Ag NPs. The present 3D nano-assemblies exhibit highly efficient and specific intrinsic oxidase-like activity even without adding any cosubstrate. PMID:25532906

Wang, Lihua; Zeng, Yi; Shen, Aiguo; Zhou, Xiaodong; Hu, Jiming

2015-02-01

388

A new microporous MOF material based on Zn(II)-polycarboxylate coordination polymer synthesized with the aid of 1,6-diaminohexane as template  

Microsoft Academic Search

A new microporous metal-organic framework (MOF) material ZBTEC-1 has been synthesized by designing infinite coordination polymer network formed between Zn(II) and 1,2,4,5-benzenetetracarboxylic acid (BTEC) under solvothermal conditions in the presence of 1,6-diaminohexane (DAH) as a single molecule template. Powder XRD data demonstrate that the ZBTEC-1 material has a new MOF structure. N2 sorption studies indicated moderately good surface area (306m2g?1)

Debraj Chandra; Mahesh W. Kasture; Asim Bhaumik

2008-01-01

389

Controlled Synthesis of Nanoporous Nickel Oxide with Two-Dimensional Shapes through Thermal Decomposition of Metal-Cyanide Hybrid Coordination Polymers.  

PubMed

Invited for the cover of this issue is the group of Yusuke Yamauchi at the National Institute for Materials Science (NIMS), Japan. The image depicts the formation of metal-cyanide hybrid coordination polymers-the rate of formation is slow as the reactant appears to be fairly stable, leading to a preferential growth. Read the full text of the article at 10.1002/chem.201404895. PMID:25641637

Zakaria, Mohamed B; Hu, Ming; Salunkhe, Rahul R; Pramanik, Malay; Takai, Kimiko; Malgras, Victor; Choi, Seyong; Dou, Shi Xue; Kim, Jung Ho; Imura, Masataka; Ishihara, Shinsuke; Yamauchi, Yusuke

2015-02-23

390

Time-resolved probes and oxidase-based biosensors using terbium(III)-guanosine monophosphate-mercury(II) coordination polymer nanoparticles.  

PubMed

A novel lanthanide coordination polymer nanoparticle (LCPN)-based ternary complex was synthesized via the self-assembly of a terbium ion (Tb(3+)) with a nucleotide (GMP) and a mercury ion (Hg(2+)) in aqueous solution. The as-prepared LCPN-based ternary complex (Tb-GMP-Hg) can be applied to the development of time-resolved luminescence assays and oxidase-based biosensors. PMID:25208485

Zhang, Min; Qu, Zhi-bei; Han, Chun-Min; Lu, Ling-Fei; Li, Yan-Yun; Zhou, Tianshu; Shi, Guoyue

2014-11-01

391

Ground states of dipolar gases in quasi-one-dimensional ring traps  

SciTech Connect

We compute the ground state of dipoles in a quasi-one-dimensional ring trap using few-body techniques combined with analytical arguments. The effective interaction between two dipoles depends on their center-of-mass coordinate and can be tuned by varying the angle between dipoles and the plane of the ring. For sufficiently weak interactions, the state resembles a weakly interacting Fermi gas or a (inhomogeneous) Lieb-Liniger gas. A mapping between the Lieb-Liniger-gas parameters and the dipolar-gas parameters in and beyond the Born approximation is established, and we discuss the effect of inhomogeneities based on a local-density approximation. For strongly repulsive interactions, the system exhibits a crystal-like localization of the particles. Their inhomogeneous distribution may be understood in terms of a simple few-body model as well as a local-density approximation. In the case of partially attractive interactions, clustered states form for sufficiently strong coupling, and the dependence of the state on particle number and orientation angle of the dipoles is discussed analytically.

Zoellner, Sascha [Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)

2011-12-15

392

Simulation of one-dimensional evolution of wind waves in a deep water  

NASA Astrophysics Data System (ADS)

A direct wave model based on the one-dimensional nonlinear equations for potential waves is used for simulation of wave field development under the action of energy input, dissipation, and nonlinear wave-wave interaction. The equations are written in conformal surface-fitted nonstationary coordinate system. New schemes for calculating the input and dissipation of wave energy are implemented. The wind input is calculated on the basis of the parameterization developed through the coupled modeling of waves and turbulent boundary layer. The wave dissipation algorithm, introduced to prevent wave breaking instability, is based on highly selective smoothing of the wave surface and surface potential. The integration is performed in Fourier domain with the number of modes M = 2048, broad enough to reproduce the energy downshifting. As the initial conditions, the wave field is assigned as train of Stokes waves with steepness ak = 0.15 at nondimensional wavenumber k = 512. Under the action of nonlinearity and energy input the spectrum starts to grow. This growth is followed by the downshifting. The total time of integration is equal to 7203 initial wave periods. During this time the energy increased by 1111 times. Peak of the spectrum gradually shifts from wavenumber nondimensional k = 512 down to k = 10. Significant wave height increases 33 times, while the peak period increases 51 times. Rates of the peak downshift and wave energy evolution are in good agreement with the JONSWAP formulation.

Chalikov, Dmitry; Babanin, Alexander V.

2014-09-01

393

Kinetics of [alpha]-helix formation as diffusion on a one-dimensional free energy surface  

NASA Astrophysics Data System (ADS)

A question of great interest is whether Kramers-rate theory can be used to describe the highly complex conformational dynamics of biopolymers. In this paper we investigate this question in the context of the kinetics of the helix-coil transition. The formation of ?-helices is possibly the dynamic process related to protein folding for which there is a better mechanistic understanding. Using a master equation-based model of the helix-coil transition we calculate the relaxation kinetics of ?-helix forming peptides after perturbations induced by `instantaneous' jumps in temperature. These calculations successfully simulate the results of recent laser-induced temperature-jump experiments. We compare the time courses generated by such detailed model with the relaxation kinetics obtained by diffusion on a one-dimensional free energy surface derived from the projection of the free energy of the helix-coil transition onto the order parameter H (i.e., number of helical peptide bonds). The diffusive kinetics calculated with a constant effective diffusion coefficient of ˜0.6 × 10 9 pb 2 s -1 are in very good agreement with the results of the detailed kinetic model, indicating that H is an appropriate reaction coordinate for ?-helix formation.

Doshi, Urmi; Muñoz, Victor

2004-12-01

394

Metallogels Derived from Silver Coordination Polymers of C3 -Symmetric Tris(pyridylamide) Tripodal Ligands: Synthesis of Ag Nanoparticles and Catalysis.  

PubMed

By applying a recently developed crystal engineering rationale, four C3 symmetric tris(pyridylamide) ligands namely 1,3,5-tris(nicotinamidomethyl)-2,4,6-triethylbenzene, 1,3,5-tris(isonicotinamidomethyl)-2,4,6-triethylbenzene, 1,3,5-tris(nicotinamidomethyl)-2,4,6-trimethylbenzene, and 1,3,5-tris(isonicotinamidomethyl)-2,4,6-trimethylbenzene, which contain potential hydrogen-bonding sites, were designed and synthesized for generating Ag(I) coordination polymers and coordination-polymer-based gels. The coordination polymers thus obtained were characterized by single-crystal X-ray diffraction. The silver metallogels were characterized by transmission electron microscopy (TEM) and dynamic rheology. Upon exposure to visible light, these silver metallogels produced silver nanoparticles (AgNPs), which were characterized by TEM, powder X-ray diffraction, energy dispersive X-ray and X-ray photoelectron spectroscopy. These NPs were found to be effectively catalyzed the reduction of 4-nitrophenolate to 4-aminophenolate without the use of any exogenous reducing agent. PMID:25351461

Paul, Mithun; Sarkar, Koushik; Dastidar, Parthasarathi

2015-01-01

395

Copper(II) coordination polymers: tunable structures and a different activation effect of hydrogen peroxide for the degradation of methyl orange under visible light irradiation.  

PubMed

By tuning the synthesis conditions, based on a conformation-sensitive ligand, 1,4-bis(1,2,4-triazole-1-methylene)-2,3,5,6-tetramethyl benzene (btmx) and Cu(NO3)2·3H2O/CuCl2·2H2O, we have obtained three Cu(ii) coordination polymers with diverse structures, namely, {[Cu(btmx)2(H2O)]·2NO3}n (), {[Cu(btmx)2(Cl)2]·5H2O}n () and [Cu(btmx)(Cl)2]n (). Complex exhibits a novel 2D ? 3D interpenetrating structure with a point symbol of 6(3). Complex features an irregular 2D grid with (4(4)·6(2)) topology. The structure of complex is a 1D double chain structure. The ultraviolet-visible absorption spectra and TG curves of these complexes are also presented and discussed. Moreover, under visible light, the coordination polymers , , and display a different activation effect of hydrogen peroxide (H2O2) for the photocatalytic decomposition of methyl orange (MO), which indicates that the coordination polymers may have bright prospects in the field of photocatalytic degradation of dyes. PMID:25427193

Liu, Lu; Wu, Dongqing; Zhao, Bei; Han, Xiao; Wu, Jie; Hou, Hongwei; Fan, Yaoting

2015-01-21

396

A series of divalent metal coordination polymers based on isomeric tetracarboxylic acids: synthesis, structures and magnetic properties.  

PubMed

Five new coordination polymers, namely, [Mn(2,2?-bipy)(H2O)2(H2L1)]n (1), {[Co(btb)(H2O)2(H2L1)]·0.5H2O}n (2), [Co(bib)(H2O)2(H2L1)]n (3), [Ni2(bpm)(H2O)3(L2)]n (4), and {[Co2(H2O)3(OH)(HL2)]·H2O}n (5), (H4L1 = 1,1?:2?,1??-terphenyl-4,4?,4??,5?-tetracarboxylic acid, H4L2 = 1,1?:2?,1??-terphenyl-3,3??,4?,5?-tetracarboxylic acid, 2,2?-bipy = 2,2?-bipyridine, btb = 1,4-bis(1,2,4-triazol-1-yl)butane, bib = 1,4-bis(imidazol-1-yl)butane, bpm = bis(4-pyridyl)amine), have been obtained under hydrothermal conditions. Complex 1 exhibits a 3D supramolecular framework based on 1D chains. Both complexes 2 and 3 are 3D supramolecular frameworks constructed from 1D zig-zag chains. Complex 4 features a 3D tetra-nodal (3,4,4,5)-connected architecture containing 1D ?-COO bridged chains with (5(2)·6(2)·7.9)(5(2)·6(4)·7(3)·8)2(5(2)·6)2(6(3)·7(2)·9) topology. Complex 5 shows a 3D penta-nodal (3,4,4,6,6)-connected net containing 1D ?-OH/?-COO bridged chains and mononuclear Co(II) nodes with a (4(2)·6(3)·8)(4(3))2(4(4)·6(2))2(4(4)·6(6)·8(5))2(4(4)·6(7)·8(4)) topology. Variable-temperature magnetic susceptibility measurements reveal that complexes 2 and 3 show antiferromagnetic interactions between the adjacent Co(II) ions, whereas 4 is a ferromagnetic system. PMID:25347690

Han, Min-Le; Duan, Ya-Ping; Li, Dong-Sheng; Xu, Guo-Wang; Wu, Ya-Pan; Zhao, Jun

2014-12-14

397

Synchrotron X-ray charge-density study of coordination polymer [Mn(HCOO)2(H2O)2]infinity.  

PubMed

Three high-quality single-crystal X-ray diffraction data sets have been measured under very different conditions on a structurally simple, but magnetically complex, coordination polymer, [Mn(HCOO)(2)(H(2)O)(2)](infinity) (1). The first data set is a conventional 100(2) K Mo(Kalpha) data set, the second is a very high resolution 100(2) K data set measured on a second-generation synchrotron source, while the third data set was measured with a tiny crystal on a high brilliance third-generation synchrotron source at 16(2) K. Furthermore, the magnetic susceptibility (chi) and the heat capacity (C(p)) have been measured from 2 to 300 K on pressed powder. The charge density of 1 was determined from multipole modeling of the experimental structure factors, and overall there is good agreement between the densities obtained separately from the three data sets. When considering the fine density features, the two 100 K data sets agree well with each other, but show small differences to the 16 K data set. Comparison with ab initio theory suggests that the 16 K APS data set provides the most accurate density. Topological analysis of the metal-ligand bonding, experimental 3d orbital populations on the Mn atoms, and Bader atomic charges indicate quite ionic, high-spin metal atoms. This picture is supported by the effective moment estimated from the magnetization measurements (5.840(2) mu(B)), but it is at variance with earlier spin density measurements from polarized neutron diffraction. The magnetic ordering originates from superexchange involving covalent interactions with the ligands, and non-ionic effects are observed in the static deformation density maps as well as in plots of the valence shell charge concentrations. Overall, the present study provides a benchmark charge density that can be used in comparison with future metal formate dihydrate charge densities. PMID:17992669

Poulsen, Rasmus D; Jørgensen, Mads R V; Overgaard, Jacob; Larsen, Finn K; Morgenroth, Wolfgang; Graber, Timothy; Chen, Yu-Sheng; Iversen, Bo B

2007-01-01

398

Syntheses, structures and properties of four 3D microporous lanthanide coordination polymers based on 3,5-pyrazoledicarboxylate and oxalate ligands  

NASA Astrophysics Data System (ADS)

Four three-dimensional lanthanide coordination polymers with reversible structural interconversions, [Ln2(Hpdc)2(C2O4)(H2O)4]n·2nH2O [Ln=Sm (1), Eu (2), Tb (3) and Dy (4)], have been synthesized by hydrothermal reactions of lanthanide nitrates with 3,5-pyrazoledicarboxylic (H3pdc) and oxalic acids. It is noteworthy that there is an in situ reaction in 1, in which H3pdc was decomposed into (ox)2- with Cu(II)-Sm(III) synergistic effect under hydrothermal conditions. These compounds are isostructural and crystallized in the monoclinic P21/c space group. The Ln(III) ions are eight-coordinated with dodecahedron coordination geometry. These polyhedra are linked by oxalate groups to form 1D zigzag chain, which are further connected by 3,5-pyrazoledicarboxylate to extend similar 3D frameworks with channels along c-axis in 1-4. These coordination polymers display the characteristic emission bands of the Ln(III) ions in the solid state and possess good thermal stabilities.

Song, Juan; Wang, Ji-Jiang; Hu, Huai-Ming; Wu, Qing-Ran; Xie, Juan; Dong, Fa-Xin; Yang, Meng-Lin; Xue, Gang-Lin

2014-04-01

399

Syntheses, structure and properties of three-dimensional pillared-layer Ag(I)-Ln(III) heterometallic coordination polymers based on mixed isonicotinate and hemimellitate ligands  

SciTech Connect

Three pillared-layer 4d-4f Ag(I)-Ln(III) heterometallic coordination polymers (HCPs), formulated as [Ln{sub 2}Ag(hma){sub 2}(ina)(H{sub 2}O){sub 2}]{sub n} nH{sub 2}O [Ln=La(1), Pr(2), Nd(3); Hina=isonicotinic acid, H{sub 3}hma=hemimellitic acid], have been synthesized under hydrothermal conditions. Single-crystal and powder X-ray diffractions confirm that they are isostructural, which features a three-dimensional (3D) pillared-layer heterometallic structure built upon the strictly alternate arrangement of lanthanide-organic layers and [Ag(ina)] pillars. The layers and pillars are connected to each other by Ln-O and Ag-O coordination bonds. The photoluminescent property of the Nd derivative (3) has also been investigated. - Graphical abstract: Three pillared-layer 4d-4f Ag(I)-Ln(III) heterometallic coordination polymers have been synthesized and structurally characterized. Highlights: Black-Right-Pointing-Pointer Three 3D pillared-layer 4d-4f HCPs were synthesized by hydrothermal reactions. Black-Right-Pointing-Pointer The synergistic coordination strategy was employed. Black-Right-Pointing-Pointer It opens new perspective for the construction of structurally diversified 4d-4f HCPs.

Li, Xinfa, E-mail: xflichem@163.com [Department of Chemistry, Zunyi Normal College, Zunyi 563002 (China)] [Department of Chemistry, Zunyi Normal College, Zunyi 563002 (China); Cao, Rong, E-mail: rcao@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)] [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

2012-12-15

400

A Cutting Plane Algorithm for the One-Dimensional Cutting Stock Problem with Multiple Stock Lengths  

E-print Network

by the following data: m Number of piece types M Number of stock types (l 1 ; : : : ; l m ) Piece lengths (L 1A Cutting Plane Algorithm for the One-Dimensional Cutting Stock Problem with Multiple Stock Lengths with column generation is generalized for the case of multiple stock lengths in the one-dimensional cutting

Scheithauer, Guntram.

401

One dimensional diffusions conditioned to be non-explosive* Ichiro Shigekaway (Kyoto University)  

E-print Network

One dimensional diffusions conditioned to be non-explosive* Ichiro Shigekaway (Kyoto University) We consider one dimensional diffusions conditioned to be non-explosive. Suppos* *e we are given a diffusion process {Xt, Px} on a state space D. Let i be its explosion

Shigekawa, Ichiro

402

One dimensional diffusions conditioned to be non-explosive Ichiro Shigekawa  

E-print Network

One dimensional diffusions conditioned to be non-explosive Ichiro Shigekawa (Kyoto University) We consider one dimensional diffusions conditioned to be non-explosive. Suppose we are given a diffusion process {Xt, Px} on a state space D. Let be its explosion time. If Px[ = ] > 0, then the measure

Shigekawa, Ichiro

403

Correlations and scaling in one-dimensional heat conduction J. M. Deutsch and Onuttom Narayan  

E-print Network

Correlations and scaling in one-dimensional heat conduction J. M. Deutsch and Onuttom Narayan of the heat current, through the Kubo formula, gives a thermal conductivity exponent of 1/3 in agreement.40.Mg I. INTRODUCTION Heat conduction in one-dimensional systems is a simple example of the general

California at Santa Cruz, University of

404

Thermal Conductivity of One-Dimensional Lattices with Self-Consistent Heat Baths  

E-print Network

Thermal Conductivity of One-Dimensional Lattices with Self-Consistent Heat Baths: A Heuristic and breathers. KEYWORDS: heat conduction, classical transport, Langevin dynamics DOI: 10.1143/JPSJ.78.044001 1. Introduction Heat conduction exhibits diversified behaviors for one- dimensional lattices in terms of heat

Li, Baowen

405

Heat conduction in one-dimensional chains Bambi Hu,1,2  

E-print Network

Heat conduction in one-dimensional chains Bambi Hu,1,2 Baowen Li,1 and Hong Zhao1,3 1 Department is whether or not the heat conduction in a one- dimensional 1D chain obeys the Fourier heat law normal thermal conductivity and if so under what condition. The first convincing result of the Fourier heat law

406

Vector spin chirality and multiferroic properties in one-dimensional spin-1/2 frustrated magnets  

E-print Network

Vector spin chirality and multiferroic properties in one-dimensional spin-1/2 frustrated magnets finite even when the magnetic order is destroyed by thermal or quantum fluctua- tions. Frustrated in quasi-one- dimensional (1D) spin-1/2 frustrated magnets, LiCu2O2 [16, 17] and LiCuVO4 [18, 19, 20

Katsumoto, Shingo

407

A one-dimensional Radon transform on SO(3) and its application to texture goniometry  

E-print Network

We consider a one-dimensional Radon transform on the group SO(3) which is motivated by texture goniometry. In particular we will derive several inversion formulae and compare them with the inversion of the one-dimensional spherical Radon transform on the three dimensional unit sphere for even functions.

Swanhild Bernstein; Helmut Schaeben

2005-02-15

408

Atomically precise self-assembly of one-dimensional structures on silicon  

E-print Network

Atomically precise self-assembly of one-dimensional structures on silicon I. Barke, T.K. Ru-magnetic surface. An interesting by-product is a memory structure with self-assembled tracks that are five atom: Low-dimensional structures; Atomic wires; Silicon surfaces; One-dimensional physics; Scanning

Himpsel, Franz J.

409

REMARKS ON THE CAUCHY PROBLEM FOR THE ONE-DIMENSIONAL QUADRATIC (FRACTIONAL) HEAT EQUATION  

E-print Network

REMARKS ON THE CAUCHY PROBLEM FOR THE ONE-DIMENSIONAL QUADRATIC (FRACTIONAL) HEAT EQUATION LUC quadratic (fractional) heat equation: ut = D2 x u u2 , t (0, T), x R or T, with 0 introduced by Bejenaru-Tao [1] for a one-dimensional quadratic Schr¨odinger equation. This approach is based

Boyer, Edmond

410

Parameter-dependent thermal conductivity of one-dimensional 4 Nianbei Li1  

E-print Network

Parameter-dependent thermal conductivity of one-dimensional 4 lattice Nianbei Li1 and Baowen Li1 the thermal conductivity of a one-dimensional 4 lattice with strong on-site harmonic potential. The expression for the thermal conductivity in terms of different parameters is derived from the effective phonon theory

Li, Baowen

411

Small Fermi surface in the one-dimensional Kondo lattice model J. C. Xavier,* E. Novais,  

E-print Network

Small Fermi surface in the one-dimensional Kondo lattice model J. C. Xavier,* E. Novais, and E, Brazil Received 14 January 2002; published 17 May 2002 We study the one-dimensional Kondo lattice model de- scription at weak coupling but becomes doubtful at strong coupling where the Kondo lattice

Miranda, Eduardo

412

Synthesis and crystal structure of the zinc(II) coordination polymer with 1,1-(1,4-butanediyl)bis(imidazole)  

NASA Astrophysics Data System (ADS)

The self-assembly of 1,1-(1,4-butanediyl)bis(imidazole) ( L) with [Zn L(NO3)2] gives the new coordination polymer C10H14N6O6Zn ( 1). The crystal structure of 1 was determined by X-ray diffraction. It crystallizes in space group with a = 7.9975(11), b = 8.4392(11), c = 13.8326(19) Å; ? = 76.876(2)°, ? = 85.892(2)°, ? = 71.0440(10)° and Z = 2. In the complex, Zn atom is coordinated to two nitrogen atoms from two molecules of L and to two oxygen atoms from two nitrate groups. Each L molecule is coordinated to two Zn atom, acting as a bridging ligand. The Zn-N bond lengths are 1.995(3) and 2.014(2) Å, and Zn-O bond lengths are 1.944(2) and 1.958(3) Å.

Chen, F.; Pan, D.-H.; Xu, Y.-P.; Yang, R.-L.; Wang, L.-Z.; Yang, M.; Luo, S.-N.

2014-12-01

413

Tunable white-light emission from mixed lanthanide (Eu³?, Gd³?, Tb³?) coordination polymers derived from 4-(dipyridin-2-yl)aminobenzoate.  

PubMed

Herein, we have developed a series of isostructural mixed Ln(3+)-4-(dipyridin-2-yl)aminobenzoate coordination polymers [Ln(3+) = Eu(3+) (1), Tb(3+) (2), and Gd(3+) (3)], and characterized and investigated their photophysical properties. The results demonstrated that by gently tuning the excitation wavelength of these mixed lanthanide complexes, white light emission can be realized with the Commission Internationale de I'Eclairage coordinates (0.32, 0.34). Furthermore, by changing the concentration profiles of lanthanide ions stoichiometrically in mixed-lanthanide complexes and exciting at particular wavelengths, various emission colours can also be successfully obtained. The antenna ligand, 4-(dipyridin-2-yl)aminobenzoic acid, provides an efficient energy transfer for the sensitization of Eu(3+) and Tb(3+) complexes and exhibits red and green emissions, respectively. Most importantly, due to the high energy (32,150 cm(-1)) of the Gd(3+) ion lowest-lying emission level, the corresponding Gd(3+) complex displays ligand-centered visible emission in the blue light region, and hence it acts as a blue emitter. Therefore, Eu(3+) and Tb(3+) complexes in conjunction with a Gd(3+) complex is a suitable choice to obtain tunable white-light-emission from Ln(3+) coordination polymers. The morphological analyses of the mixed lanthanide coordination polymers by transmission electron microscopy (TEM) disclose that these compounds exist as unique crystalline nano-rods with an average diameter of 200 nm. The developed mixed lanthanide complexes also exhibit high thermal stability (~420 °C). PMID:24903008

Ramya, A R; Varughese, Sunil; Reddy, M L P

2014-07-28

414

A Co(II) thiocyanato coordination polymer with 4-(3-phenylpropyl)pyridine: the influence of the co-ligand on the magnetic properties.  

PubMed

Three new coordination compounds with the composition Co(NCS)2(4-(3-phenylpropyl)pyridine)4 (1), Co(NCS)2(4-(3-phenylpropyl)pyridine)4(H2O)2 (2) and [Co(NCS)2(4-(3-phenylpropyl)pyridine)2]n (3) were prepared and investigated. The crystal structures of compounds 1 and 2 consist of discrete complexes, in which the Co(II) cations are coordinated by only terminal N-bonded thiocyanato anions. In the crystal structure 3 of the Co(II) cations are linked into chains by pairs of ?-1,3-bridging thiocyanato anions. DTA-TG measurements on compound 1 show decomposition without the formation of 3 as an intermediate. In contrast, on heating compound 2 two water molecules are removed in the first step leading to the formation of compound 3 in the second step. Magnetic measurements on reveal ferromagnetic interactions between Co(II) ions along chains with J = 29.5(1) K, and also ferromagnetic interactions between chains with zJ' = 0.38(1) K. The ferromagnetic transition is observed at 3.3 K, which is confirmed by specific heat measurements. The temperature dependent ac susceptibility shows slow relaxations above and below 3.3 K. The results for this quasi-one dimensional Ising ferromagnet, having also some features of a cluster spin-glass, are compared with those of related compounds. PMID:25318637

Werner, Julia; Rams, Micha?; Tomkowicz, Zbigniew; Näther, Christian

2014-12-14

415

Strain-tunable one dimensional photonic crystals based on zirconium dioxide/slide-ring elastomer nanocomposites for mechanochromic sensing.  

PubMed

We demonstrate the fabrication and performance of tunable, elastic organic/inorganic composite one-dimensional photonic crystals (1DPCs) in the visible spectrum. By controlling the composition of high refractive index metal oxide nanoparticle/polymer composites, a refractive index difference of 0.18 between the filled and unfilled polymer layers can be achieved while maintaining desirable flexibility and elasticity. This index contrast is achieved with a loading of 70 wt % zirconium dioxide nanoparticles within a slide-ring elastomer matrix, which is composed of topologically cross-linked polyrotaxane polyols. The large refractive index contrast enables high reflectivity while simultaneously minimizing the number of layers necessary, compared to purely polymer systems. Because the films are both flexible and elastic, these nanocomposite 1DPCs can function as colorimetric strain sensors. We demonstrate the sensing behavior of these 1DPCs by applying over 40% strain, resulting in a visible color shift across the visible spectrum from red to blue. 1DPCs of just 6 periods maintain reflectance of 40% throughout the visible spectrum, with a tensile mechanochromic sensitivity (??/??max) as high as -6.05 nm/%. PMID:25647806

Howell, Irene R; Li, Cheng; Colella, Nicholas S; Ito, Kohzo; Watkins, James J

2015-02-18

416

Synthesis, structures and properties of a family of four two-dimensional coordination polymers constructed from 5-hydroxyisophthalate  

SciTech Connect

Four 2D coordination polymers (CPs) with different structures containing the multifunctional ligand 5-hydroxyisophthalate (5-OH-BDC{sup 2?}), [Zn(5-OH-BDC)(btb)]·2H{sub 2}O (1), [Cd(5-OH-BDC)(btp)(H{sub 2}O)]·3H{sub 2}O (2), [Cd(5-OH-BDC)(bth){sub 2}(H{sub 2}O)]·H{sub 2}O (3) and [Pb(5-OH-BDC)]·H{sub 2}O (4) [btp=1, 3-bis(1,2,4-triazol-1-yl)propane, btb=1,4-bis(1,2,4-triazol-1-yl)butane, bth=1, 6-bis(1,2,4-triazol-1-yl)hexane] were obtained. 1–3 were synthesised hydrothermally, while 4 was obtained under ambient condition. The adjacent (2D?2D) polycatenated 2D layers of 1 polythread in a parallel manner to form an unusual 2D?3D polythreaded framework. 2 contains an undulated 2D (4, 4) network and further extends into an “embracing” double-layer structure through the C–H···? and ?···? stacking interactions. 3 exhibits a non-interpenetrating 2D (4, 4)-network. 4 exhibits a 2D double-layered binodal (4, 4)-net containing oblong nanochannels with symbol (4{sup 3}6{sup 3}){sub 2}. Reversible dehydration–rehydration is observed in 1, 2 and 4, which fall within the category of “recoverable collapsing” and “guest-induced re-formation” frameworks, while 3 exhibits irreversible dehydration–rehydration behaviour. The solid state fluorescent properties of 1–4 have been investigated. -- Graphical abstract: Among four 2D CPs reported, 1 is an unusual 2D?3D polythreaded framework. 4 exhibits 2D double-layered binodal (4, 4)-net containing nanochannels. Reversible dehydration–rehydration is observed in 1, 2 and 4. Highlights: • Four 2D CPs based on 5-hydroxyisophthalate with d{sup 10} and Pb(II) ions were reported. • 1 is an unusual 2D?3D polythreaded framework. • 4 shows a binodal (4, 4)-connected 2D double-layer network with nanochannels. • The materials 1, 2 and 4 show reversible dehydration–rehydration behaviours. • Solid state fluorescent properties were investigated.

Zhang, Kou-Lin, E-mail: klzhang@yzu.edu.cn [Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Zhang, Jing-Bo; Jing, Chu-Yue; Zhang, Lei [Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Walton, Richard I. [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Zhu, Peizhi, E-mail: pzzhu@yzu.edu.cn [Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Ng, Seik Weng [Department of Chemistry, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2014-03-15

417

3-Hydroxynaphthalene-2-carboxylic acid supported grid-like structure of cadmium chloride coordination polymer with 1,3-bis(4-pyridyl)propane  

NASA Astrophysics Data System (ADS)

Inclusion of 3-hydroxynaphthalene-2-carboxylic acid in grid-like structure of a coordination-polymer 1 formed from 1,3-bis(4-pyridyl)propane (LL) with cadmium(II) chloride is described. Components of the grid are comprised of cyclic secondary building blocks of 4 + 4 condensation of LLs and cadmium ions. Guest 3-Hydroxynaphthalene-2-carboxylic acid (Hnap) molecules possess intramolecular hydrogen bonds and Csbnd H⋯? and Osbnd H⋯Cl interactions with host coordination polymer. Among four pyridyl rings coordinated to each cadmium ion, two pyridyl rings are distinguishable from other two pyridyl rings as they are involved in Csbnd H⋯Cl interactions. 1H NMR experiments show that Hnap has a role in formation of grid-like structure. A similar reaction of chelating ligand 2,2?-bipyridine and Hnap with cadmium chloride led to a mono-nuclear complex bis(2,2?-bipyridine)-bis(3-hydroxynaphthalene-2-carboxylato)cadmium(II) (2) which was structurally characterized.

Phukan, Nithi; Baruah, Jubaraj B.

2014-11-01

418

Polymers  

NSDL National Science Digital Library

This page contains two documents explaining ring and cross link polymers. The topic is covered at an advanced level in relation to nanotechnology and requires background knowledge in eight grade science. A powerpoint with illustrations and instructor guide (available as both a Microsoft Word Document and PDF) containing activities are included to aid in teaching this subject.

419

Two one-dimension copper(II) coordination polymers based on imine-based bidentate Schiff-base ligand: Synthesis, crystal structure and luminescent properties  

NASA Astrophysics Data System (ADS)

Two new one-dimension copper(II) coordination polymers [CuL 2(NCS) 2] n ( 1) and [CuL 2(NO 3) 2] n ( 2) (L = (C 5H 4N)C(CH 3) dbnd N-N dbnd (CH 3)C(C 5H 4N)) have been synthesized and characterized by IR, elemental analysis, TG technique and X-ray crystallography. Each Cu(II) atom has a distorted octahedral N 6 ( 1) or N 4O 2 ( 2) environment with four pyridyl N atoms from four ligands and two N atoms from two NCS - anions for polymer 1 or two O atoms from two NO 3- anions for polymer 2, respectively. A pair of bis-monodentate bridging ligands links two Cu(II) centers to form one dimension chain structure containing bimetallic 22-membered macrometallacyclic rings. 1D chain is held together with its neighboring ones via C-H⋯S hydrogen bonds for 1 and C-H⋯O hydrogen bonds, C-H⋯? interactions for 2 to form a 3D supramolecular structure, respectively. The luminescent properties of the polymers 1 and 2 were investigated in the solid state at room temperature.

Dang, Dong-Bin; Li, Meng-Meng; Bai, Yan; Wang, Jun-Li

2011-12-01

420

Analysis of one-dimensional pure-exchange NMR experiments for studying dynamics with broad distributions of correlation times  

NASA Astrophysics Data System (ADS)

One-dimensional (1D) exchange NMR experiments can elucidate the geometry, time scale, memory, and heterogeneity of slow molecular motions (1 ms-1 s) in solids. The one-dimensional version of pure-exchange (PUREX) solid-state exchange NMR, which is applied to static samples and uses the chemical shift anisotropy as a probe for molecular motion, is particularly promising and convenient in applications where site resolution is not a problem, i.e., in systems with few chemical sites. In this work, some important aspects of the 1D PUREX experiment applied to systems with complex molecular motions are analyzed. The influence of intermediate-regime (10 ?s-1 ms) motions and of the distribution of reorientation angles on the pure-exchange intensity are discussed, together with a simple method for estimating the activation energy of motions occurring with a single correlation time. In addition, it is demonstrated that detailed information on the motional geometry can be obtained from 1D PUREX spectral line shapes. Experiments on a molecular crystal, dimethyl sulfone, confirm the analysis quantitatively. In two amorphous polymers, atactic polypropylene (aPP) and polyisobutylene (PIB), which differ only by one methyl group in the repeat unit, the height of the normalized exchange intensity clearly reveals a striking difference in the width of the distribution of correlation times slightly above the glass transition. The aPP shows the broad distribution and Williams-Landel-Ferry temperature dependence of correlation times typical of polymers and other "fragile" glass formers. In contrast, the dynamics in PIB occur essentially with a single correlation time and exhibits Arrhenius behavior, which is more typical of "strong" glass formers; this is somewhat surprising given the weak intermolecular forces in PIB.

deAzevedo, E. R.; Tozoni, J. R.; Schmidt-Rohr, K.; Bonagamba, T. J.

2005-04-01

421

Analysis of one-dimensional pure-exchange NMR experiments for studying dynamics with broad distributions of correlation times.  

PubMed

One-dimensional (1D) exchange NMR experiments can elucidate the geometry, time scale, memory, and heterogeneity of slow molecular motions (1 ms-1 s) in solids. The one-dimensional version of pure-exchange (PUREX) solid-state exchange NMR, which is applied to static samples and uses the chemical shift anisotropy as a probe for molecular motion, is particularly promising and convenient in applications where site resolution is not a problem, i.e., in systems with few chemical sites. In this work, some important aspects of the 1D PUREX experiment applied to systems with complex molecular motions are analyzed. The influence of intermediate-regime (10 micros-1 ms) motions and of the distribution of reorientation angles on the pure-exchange intensity are discussed, together with a simple method for estimating the activation energy of motions occurring with a single correlation time. In addition, it is demonstrated that detailed information on the motional geometry can be obtained from 1D PUREX spectral line shapes. Experiments on a molecular crystal, dimethyl sulfone, confirm the analysis quantitatively. In two amorphous polymers, atactic polypropylene (aPP) and polyisobutylene (PIB), which differ only by one methyl group in the repeat unit, the height of the normalized exchange intensity clearly reveals a striking difference in the width of the distribution of correlation times slightly above the glass transition. The aPP shows the broad distribution and Williams-Landel-Ferry temperature dependence of correlation times typical of polymers and other "fragile" glass formers. In contrast, the dynamics in PIB occur essentially with a single correlation time and exhibits Arrhenius behavior, which is more typical of "strong" glass formers; this is somewhat surprising given the weak intermolecular forces in PIB. PMID:15945644

deAzevedo, E R; Tozoni, J R; Schmidt-Rohr, K; Bonagamba, T J

2005-04-15

422

The thermal energy of a scalar field in a one-dimensional compact space  

E-print Network

We discuss some controverted aspects of the evaluation of the thermal energy of a scalar field in a one-dimensional compact space. The calculations are carried out using a generalised zeta function approach.

E. Elizalde; A. C. Tort

2002-06-06

423

Experimental Techniques for the Mechanical Characterization of One-Dimensional Nanostructures  

E-print Network

Experimental Techniques for the Mechanical Characterization of One-Dimensional Nanostructures Y January 2007 # Society for Experimental Mechanics 2007 Abstract New materials and nanostructures with su- cation of these materials and nanostructures requires accurate mechanical characterization, which in turn

Espinosa, Horacio D.

424

Speaker Masatoshi Fukushima Title of Talk I: One dimensional diffusions and their Dirichlet forms  

E-print Network

Speaker Masatoshi Fukushima Title of Talk I: One dimensional diffusions and their Dirichlet forms subspace of the active reflected Dirichlet space based on X. Fang, M. Fukushima and J. Ying, On regular

Chen, Zhen-Qing

425

Simulating higher-dimensional geometries in GADRAS using approximate one-dimensional solutions.  

SciTech Connect

The Gamma Detector Response and Analysis Software (GADRAS) software package is capable of simulating the radiation transport physics for one-dimensional models. Spherical shells are naturally one-dimensional, and have been the focus of development and benchmarking. However, some objects are not spherical in shape, such as cylinders and boxes. These are not one-dimensional. Simulating the radiation transport in two or three dimensions is unattractive because of the extra computation time required. To maintain computational efficiency, higher-dimensional geometries require approximations to simulate them in one-dimension. This report summarizes the theory behind these approximations, tests the theory against other simulations, and compares the results to experimental data. Based on the results, it is recommended that GADRAS users always attempt to approximate reality using spherical shells. However, if fissile material is present, it is imperative that the shape of the one-dimensional model matches the fissile material, including the use of slab and cylinder geometry.

Thoreson, Gregory G.; Mitchell, Dean James; Harding, Lee T.

2013-02-01

426

On a general solution of the one-dimensional stationary Schrodinger equation  

E-print Network

The general solution of the one-dimensional stationary Schroedinger equation in the form of a formal power series is considered. Its efficiency for numerical analysis of initial value and boundary value problems is discussed.

Vladislav V. Kravchenko

2007-09-19

427

One-dimensional two-phase reacting gas nonequilibrium performance program  

NASA Technical Reports Server (NTRS)

Computer program calculates the inviscid one-dimensional equilibrium, frozen, and nonequilibrium nozzle expansion of propellant exhaust mixtures containing carbon, hydrogen, oxygen, nitrogen, fluorine, chlorine and either aluminum, beryllium, boron or lithium. This program performs calculations for conical nozzles only.

Cherry, S. S.; Frey, H. M.; Kliegel, J. R.; Quan, V.

1968-01-01

428

One-dimensional nanostructure-guided chain reactions: Harmonic and anharmonic interactions  

E-print Network

We have performed a parametric study of self-propagating chain reactions along a one-dimensional bead-spring array. The coupling between beads is modeled using harmonic and anharmonic Fermi-Pasta-Ulam (FPU)-? and ?[superscript ...

Nair, Nitish

429

MULTI - A computer code for one-dimensional multigroup radiation hydrodynamics  

Microsoft Academic Search

The basic physical equations as well as a computer code for the simulation of one-dimensional radiation hydrodynamics are described. The hydrodynamic equations are combined with a multigroup method for the radiation transport. The code, written in standard FORTRAN-77, is characterized by one-dimensional planar geometry with multilayer structure. A time-splitting schema has been adopted with implicit finite-differencing formulation (including the hydrodynamics),

R. Ramis; R. Schmalz; J. Meyer-Ter-Vehn

1988-01-01

430

Renormalization group study of transport through a superconducting junction of multiple one-dimensional quantum wires  

Microsoft Academic Search

We investigate transport properties of a superconducting junction of many (N=>2) one-dimensional quantum wires. We include the effect of electron-electron interaction within the one-dimensional quantum wire using a weak interaction renormalization group procedure. Due to the proximity effect, transport across the junction occurs via direct tunneling as well as via the crossed Andreev channel. We find that the fixed point

Sourin Das; Sumathi Rao; Arijit Saha

2008-01-01

431

Giant enhancement of the Raman response due to one-dimensional ZnO nanostructures.  

PubMed

We observed giant enhancement of the Raman intensity from 4-Mpy molecules adsorbed on semiconducting one-dimensional ZnO nanostructures, nanowires and nanocones, without involving any noble metals. Interestingly, the enhancement is strongly dependent on the geometry of ZnO nanostructures and can mainly be explained by the cavity-like structural resonance of the electric field. Our results can be applied to systematically create hot spots for Raman signal enhancement using one-dimensional semiconducting nanomaterials. PMID:25355156

Shin, Hae-Young; Shim, Ee-Le; Choi, Young-Jin; Park, Jong-Hyurk; Yoon, Seokhyun

2014-12-21

432

VLSI implementation of the universal one-dimensional CAT\\/ICAT  

Microsoft Academic Search

The first VLSI implementation of the universal one-dimensional cellular automata transform (CAT) as well as inverse CAT (ICAT) is present in this paper. To facilitate the development of a universal one-dimensional CAT\\/ICAT chip, we adopted a CA cell structure with programmable additive rules to generate CA bases, and utilized pipelined phase accumulators to perform the operation of the CAT\\/ICAT. The

Rong-jian Chen; Jui-lin Lai

2002-01-01

433

Liquid-gas transition of neon in quasi-one-dimensional environments  

NASA Astrophysics Data System (ADS)

We characterize the behavior of a system of Ne20 atoms in a pure one-dimensional environment between 12 and 30 K by means of path integral Monte Carlo calculations. This is a reasonable model to describe neon absorbed inside a narrow carbon nanotube. When embedded in a bundle of those tubes, this quasi-one-dimensional system can undergo a liquid-gas phase transition if nanotubes are narrow and close enough.

Brualla, L.; Gordillo, M. C.

2003-08-01

434

Two-Dimensional Coordination Polymers Constructed Using, Simultaneously, Linear and Angular Spacers and Cobalt(II) Nodes. New Examples of Networks of Single-Ion Magnets.  

PubMed

Two novel bidimensional coordination polymers, [Co(azbbpy)(4,4'-bipy)0.5(DMF)(NCS)2]·MeOH (1) and [Co(azbbpy)(bpe)0.5(DMF)(NCS)2]·0.25H2O (2), resulted from the assembling of cobalt(II) ions by 1,3-bis(4-pyridyl)azulene, using either 4,4'-bipyridyl or 1,2-bis(4-pyridyl)ethylene as neutral spacers. The cobalt(II) nodes in 1 and 2 act as single-ion magnets (SIMs). PMID:25521046

Ion, Adrian E; Nica, Simona; Madalan, Augustin M; Shova, Sergiu; Vallejo, Julia; Julve, Miguel; Lloret, Francesc; Andruh, Marius

2015-01-01

435

Formation of conglomerate crystals: A closer look at helical pitches and unit cell volumes of P- and M-helical copper(II) coordination polymers  

NASA Astrophysics Data System (ADS)

Conglomerate crystals of tubular helical coordination polymers, P- and M-[CuCl2(L)(S)]·S? (L = dimethylbis(4-pyridyl)silane; S = Me2SO, HCONMe2; S? = Me2SO, 1/2Et2O), have been obtained in high yields. Their helical pitches and unit cell volumes are sensitive to the molecular size of ligand, co-ligand, and solvate molecules. Both crystals evaporate solvate molecules at around 100 °C, and then calcination at 600 °C finally produces micro-sized chaotic surface materials consisting of copper(II) oxide/silicon(IV) oxide composite with evolving burned organics.

Moon, So Yun; Park, Kyung Hwan; Lee, Haeri; Noh, Tae Hwan; Jung, Ok-Sang

2013-09-01

436

Spontaneous resolution to absolute chiral induction: pseudo-Kagomé type homochiral Zn(II)/Co(II) coordination polymers with achiral precursors.  

PubMed

It is observed that conglomerate crystallization of achiral precursors yielding racemate metal organic frameworks/coordination polymers (MOFs/CPs) can be driven to absolute homochiral crystallization of the desired enantiomorph by utilizing a suitable chiral induction agent. In a series of crystallization experiments isostructural Zn and Co homochiral CPs (1P, 1M and 2P, 2M) are prepared using the achiral precursors. In the presence of enantiopure camphoric acid, the crystallization process prefers absolute chiral induction over conglomerate formation which is established by single crystal X-ray diffraction and CD spectroscopy. PMID:24107095

Bisht, Kamal Kumar; Suresh, Eringathodi

2013-10-23

437

First examples of ternary lanthanide 5-aminoisophthalate complexes: Hydrothermal syntheses and structures of lanthanide coordination polymers with 5-aminoisophthalate and oxalate  

NASA Astrophysics Data System (ADS)

Two new lanthanide coordination polymers with mixed-carboxylates, [Ln(OX)(HAPA)(H 2O)] n[Ln = Eu ( 1), Ho ( 2); H 2APA = 5-aminoisophthalic acid; OX = oxalate] were obtained by hydrothermal reactions, and characterized by single crystal X-ray diffraction, elemental analysis and IR spectra. Complexes 1 and 2 are both 3-D supramolecular structure, in which lanthanide ions are bridged by oxalate and 5-aminoisophthalate ligands forming 2-D metal-organic framework, and 2-D networks are further architectured to form 3-D supramolecular structures by hydrogen bonds. The two carboxylate groups of H 2APA ligand are all deprotonated and exhibit chelating and bridging bidentate coordination modes, respectively, and the amino group in HAPA presents - NH3+ in the titled complexes. The thermogravimetric analysis was carried out to examine the thermal stability of the titled complexes. And the photoluminescence property of 1 was investigated.

Liu, Chong-Bo; Wen, Hui-Liang; Tan, Sheng-Shui; Yi, Xiu-Guang

2008-05-01

438

Nonlinear wake potential and stopping power for charged particles interacting with a one-dimensional electron gas  

SciTech Connect

We examine the interaction of particles with a one-dimensional electron gas by employing the quantum hydrodynamic (QHD) theory, where the nonlinear wake potential and stopping power have been numerically calculated by solving the nonlinear QHD equations with flux corrected transport (FCT) numerical method. In our calculation, the nonlinear effects on the wake potential and stopping power are clearly observed and presented. In the moving coordinate, comparisons are made between the nonlinear and linear wake potentials, in which the maximum values are larger and more oscillations appear behind the projectile in a nonlinear case in contrast to that in a linear case. The nonlinear wake potentials show a clear dependence on time, that is, the FCT algorithm solves the nonlinear QHD equations by time integration starting from the initial time. It is shown that the nonlinear effects can enhance the wake potential and stopping power for particle velocities greater than a few Bohr velocities.

Zhang Ya; Song Yuanhong; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2011-11-15