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1

A novel pentanuclear zinc coordination polymer with one-dimensional chain: synthesis, structure and luminescent property.  

PubMed

One interesting pentanuclear zinc coordination polymer, [Zn(5)(OH)(2)(DTBA)(4)](n) (1) (DTBA=2,2'-dithiobisbenzoic acid) has been synthesized by hydrothermal method, and characterized by X-ray single crystal diffraction, elemental analyses, IR and TGA. The pentanuclear zinc unit exhibits pentagon configuration, which acts as secondary building unit to construct a one-dimensional chain structure by DTBA ligands. As far as we know, this kind of pentagon zinc unit is unprecedented. In addition, upon the excitation at 390 nm, the blue-fluorescence at 448 nm of the compound 1 was observed. PMID:22902584

Li, Ya-Min; Xiao, Chang-Yu; Guo, Shao-Shuai; Li, Shu; Cui, Cai-Yan; Li, Jun-Rui

2012-11-01

2

A novel pentanuclear zinc coordination polymer with one-dimensional chain: Synthesis, structure and luminescent property  

NASA Astrophysics Data System (ADS)

One interesting pentanuclear zinc coordination polymer, [Zn5(OH)2(DTBA)4]n (1) (DTBA = 2,2'-dithiobisbenzoic acid) has been synthesized by hydrothermal method, and characterized by X-ray single crystal diffraction, elemental analyses, IR and TGA. The pentanuclear zinc unit exhibits pentagon configuration, which acts as secondary building unit to construct a one-dimensional chain structure by DTBA ligands. As far as we know, this kind of pentagon zinc unit is unprecedented. In addition, upon the excitation at 390 nm, the blue-fluorescence at 448 nm of the compound 1 was observed.

Li, Ya-Min; Xiao, Chang-Yu; Guo, Shao-Shuai; Li, Shu; Cui, Cai-Yan; Li, Jun-Rui

2012-11-01

3

A one-dimensional coordination polymer based on a di-Schiff base supported trinuclear CuII subunit.  

PubMed

A novel one-dimensional Cu(II) coordination polymer, catena-poly[bis(?(4)-3-{[2-(3-hydroxy-2-oxidobenzylidene)hydrazinylidene]methyl}benzene-1,2-diolato)dimethanoltricopper(II)], [Cu(3)(C(14)H(10)N(2)O(4))(2)(CH(3)OH)(2)](n), (I), was constructed with a di-Schiff base supported centrosymmetric trinuclear Cu(II) subunit. In the subunit, two peripheral symmetry-related Cu(II) cations have square-pyramidal CuNO(4) geometry and the central third Cu(II) cation lies on an inversion centre with octahedral CuN(2)O(4) geometry. In (I), each partially deprotonated di-Schiff base 3-{[2-(3-hydroxy-2-oxidobenzylidene)hydrazinylidene]methyl}benzene-1,2-diolate ligand (Hbcaz(3-)) acts as a heptadentate ligand to bind the Cu(II) centres into chains along the a axis. A centrosymmetric Cu(2)O(2) unit containing an asymmetrically bridging O atom, being axial at one Cu atom and equatorial at the other Cu atom, links the trinuclear Cu(II) subunit into a one-dimensional chain, which is reinforced by intramolecular phenol-methanol O-H...O and methanol-phenolate O-H...O hydrogen bonds. Interchain ?-? stacking interactions between pyrocatechol units, with a distance of 3.5251?(18)?Å, contribute to the stability of the crystal packing. PMID:22476144

Zhang, Liangliang; Liu, Fuling; Yuan, Shuai; Wang, Xiaoyang; Sun, Di

2012-04-01

4

One-dimensional helical coordination polymers of cobalt(II) and iron(II) ions with 2,2?-bipyridyl-3,3?-dicarboxylate (BPDC 2?)  

Microsoft Academic Search

One-dimensional (1-D) helical coordination polymers, [MII(H2O)3(BPDC)]n·nH2O (M=Co (1), Fe (2)), have been prepared by the self-assembly of cobalt(II) and iron(II) ions, respectively, with 2,2?-bipyridyl-3,3?-dicarboxylic acid (H2BPDC) in an aqueous solution. X-ray crystal structures of compounds 1 and 2 show that each metal ion displays a distorted octahedral coordination geometry including three water oxygen atoms, one oxygen atom of the carboxylate

Ock Keum Kwak; Kil Sik Min; Bong Gon Kim

2007-01-01

5

Synthesis, crystal structures and luminescent properties of two one-dimensional cadmium(II) coordination polymers generated from polydentate Schiff-base ligand  

NASA Astrophysics Data System (ADS)

Two new one-dimensional coordination polymers {[CdL2(H2O)2](NO3)2(H2O)6}n (1) and {[CdLI2](H2O)(CH3OH)}n (2) have been synthesized and characterized by IR, elemental analysis, TG technique, XRPD and complete single crystal structure analyses, where L is bis(pyridin-4-ylmethylene)biphenyl-2,2'-dicarbohydrazide. The Cd(II) atom has a distorted octahedral coordination geometry with N4O2 donors from four ligands and two water molecules in 1 and a distorted tetrahedral coordination geometry with NOI2 donors from two ligands and two I- anions in 2, respectively. Polymer 1 shows a 1D framework structure containing bimetallic 42-membered quadrangular ring units. The adjacent 1D chains are interacted forming a 3D supramolecular network structure through multiform hydrogen bond interactions. In comparison with 1, polymer 2 is a new rampart-type chain and each chain is interacted with each other through hydrogen bond interactions to lead a 2D layer. The luminescent properties of the polymers 1 and 2 were investigated in the solid state at room temperature.

Bai, Yan; Wang, Jun-Li; Dang, Dong-Bin; Zheng, Yan-Ning

2012-11-01

6

Two one-dimensional coordination polymers generated from a new benzimidazole bridging ligand and CdX2 (X = Br and I).  

PubMed

The novel asymmetric bridging ligand 1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole (L) has been used to construct the coordination polymers catena-poly[[[dibromidocadmium(II)]-?3-1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole] monohydrate], {[CdBr2(C24H18N4)]·H2O}n, (I), and catena-poly[[diiodidocadmium(II)]-?3-1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole], [CdI2(C24H18N4)]n, (II). Compounds (I) and (II) are closely related one-dimensional polymers based on 16- and 20-membered macrocycles along the chains, but they are not isomorphous. The chains are crosslinked into a two-dimensional network via hydrogen bonds and ?-? interactions in (I), and into a three-dimensional framework through ?-? interactions in (II). One well-ordered solvent water molecule per asymmetric unit is included in (I) and forms O···Br hydrogen bonds. PMID:23629894

Zhang, Yue-Feng; Ma, Jian-Ping; Liu, Qi-Kui; Dong, Yu-Bin

2013-05-01

7

One-dimensional transport in polymer nanofibers.  

PubMed

We report our transport studies in quasi-one-dimensional (1D) conductors-helical polyacetylene fibers doped with iodine-and the data analysis for other polymer single fibers and tubes. We found that at 30 K

Aleshin, A N; Lee, H J; Park, Y W; Akagi, K

2004-11-01

8

One-dimensional zig-zag type coordination polymers of Ni(II) and Cu(II) containing 1,3-benzenedicarboxylate and  

E-print Network

involving coordination polymers. Compared to malonic, succinic, glutaric and adipic acids which have. Introduction Synthesis and structural characterization of framework materials involving metal dicarboxylate flexible ­CH2­ spacer functions of varying lengths, benzenedicarboxylic acids have a rigid aromatic unit

Li, Jing

9

Syntheses and Characterization of New Nickel Coordination Polymers with 4,4?-Dipyridylsulfide. Dynamic Rearrangements of One-Dimensional Chains Responding to External Stimuli: Temperature Variation and Guest Releases/Re-Inclusions  

PubMed Central

Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4?-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO3)2·6H2O with dps in EtOH yielded [Ni(dps)2(NO3)2] ·EtOH (1), which had channels filled with guest EtOH molecules among the four Ni(dps)2 chains. This coordination polymer reversibly transformed the channel structure responding to temperature variations. Immersion of 1 in m-xylene released guest EtOH molecules to yield a guest-free coordination polymer [Ni(dps)2(NO3)2] (2a), which was also obtained by treatment of Ni(NO3)2·6H2O with dps in MeOH. On the other hand, removal of the guest molecules from 1 upon heating at 130 °C under reduced pressure produced a guest-free coordination polymer [Ni(dps)2(NO3)2] (2b). Although the 2a and 2b guest-free coordination polymers have the same formula, they showed differences in the assembled structures of the one-dimensional chains. Exposure of 2b to EtOH vapor reproduced 1, while 2a did not convert to 1 in a similar reaction. Reaction of Ni(NO3)2·6H2O with dps in acetone provided [Ni(dps)(NO3)2(H2O)] ·Me2CO (4) with no channel structure. When MeOH or acetone was used as a reaction solvent, the [Ni(dps)2(NO3)2] · (guest molecule) type coordination polymer, which was observed in 1, was not formed. Nevertheless, the reaction of Ni(NO3)2·6H2O with dps in MeOH/acetone mixed solution produced [Ni(dps)2(NO3)2]·0.5(MeOH·acetone) (5), which has an isostructural Ni-dps framework to 1. PMID:21152276

Kondo, Mitsuru; Takahashi, Hideaki; Watanabe, Hirotaka; Shimizu, Yusuke; Yamanishi, Katsunori; Miyazawa, Makoto; Nishina, Naoko; Ishida, Yutaka; Kawaguchi, Hiroyuki; Uchida, Fumio

2010-01-01

10

Coordination polymers  

Microsoft Academic Search

This paper is a review of the metal complex forming coordination polymers. A polymer–metal complex is composed of synthetic polymer and metal ions bound to the polymer ligand by a coordinate bond. A polymer ligand contains anchoring sites like nitrogen, oxygen or sulphur obtained either by the polymerization of monomer possessing the coordinating site or by a chemical reaction between

T. Kaliyappan; P. Kannan

2000-01-01

11

Three one-dimensional coordination polymers based on 1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole and HgX2 (X = Cl, Br and I).  

PubMed

A new 2,2'-bi-1H-benzimidazole bridging organic ligand, namely 1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole, C26H20N6, L or (I), has been synthesized and used to create three new one-dimensional coordination polymers, viz. catena-poly[[dichloridomercury(II)]-?-1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole], [HgCl2(C26H20N6)]n, (II), and the bromido, [HgBr2(C26H20N6)]n, (III), and iodido, [HgI2(C26H20N6)]n, (IV), analogues. Free ligand L crystallizes with two symmetry-independent half-molecules in the asymmetric unit and each L molecule resides on a crytallographic inversion centre. In structures (II)-(IV), the L ligand is also positioned on a crystallographic inversion centre, whereas the Hg centre resides on a crystallographic twofold axis. Compound (I) adopts an anti conformation in the solid state and forms a two-dimensional network in the crystallographic bc plane via ?-? and C-H...? interactions. The three Hg(II) coordination complexes, (II)-(IV), have one-dimensional zigzag chains composed of L and HgX2 (X = Cl, Br and I), and the Hg(II) centres are in a distorted tetrahedral [HgX2N2] coordination geometry. Complexes (III) and (IV) are isomorphous, whereas complex (II) displays an interesting conformational difference from the others, i.e. a twist in the flexible bridging ligand. PMID:24399223

Li, Ai-Guo; Liu, Qi-Kui; Li, Yan-An; Liu, Zhi-Xian; Dong, Yu-Bin

2014-01-01

12

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

PubMed

In the title one-dimensional Zn(II) coordination polymer, [Zn(C10H8O4)0.5Cl(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

2014-11-15

13

Two new one-dimensional luminescent silver(I) and lead(II) coordination polymers containing the flexible ligand 2-(1 H-imidazole-1-yl)acetic acid  

Microsoft Academic Search

The free ligand, 2-(1H-imidazole-1-yl)acetate (Hima, 1), was crystallized from the mixture solution of 1. Two new coordination polymers, [Ag(Hima)(NO3)] (2) and {[Pb(Hima)2(NO3)](NO3)}n (3), are achieved by reaction of a flexible Hima, AgNO3 and Pb(NO3), respectively. In 2, the silver(I) atom is coordinated by four oxygen atoms from three carboxylate groups and one nitrate ion in a distorted tetrahedral environment. The

Yong-Tao Wang; Ting-Xiao Qin; Chao Zhao; Gui-Mei Tang; Tian-Duo Li; Yue-Zhi Cui; Jun-Ying Li

2009-01-01

14

One-dimensional nanowire assembly based on oriented polymer nanofibers  

Microsoft Academic Search

We develop a simple method for the parallel assembly of nanowires (NWs) based on oriented polymer nanofiber films. The nanowires dispersed in solution are aligned at the central space of parallel nanochannels formed by the well-oriented nanofibers as a result of the capillarity. Then, a general contact printing is used to realize the transfer of the nanowires from the donor

Shancheng Yan; Zhongdang Xiao; Dong Hu; Jiansheng Wu

2011-01-01

15

Fresnel lenses fabricated by femtosecond laser micromachining on polymer one-dimensional photonic crystal  

NASA Astrophysics Data System (ADS)

We report the fabrication of micro-Fresnel lenses by femtosecond laser surface ablation on one-dimensional (1-D) polymer photonic crystals. This device is designed to focus the transmitted wavelength (520 nm) of the photonic crystal and filter the wavelengths corresponding to the photonic band-gap region (centered at 630 nm, ranging from 530 to 700 nm). Integration of such devices in a wavelength selective light harvesting and filtering microchip is envisaged.

Guduru, Surya S. K.; Scotognella, Francesco; Criante, Luigino; Vazquez, Rebeca Martinez; Ramponi, Roberta; Vishnubhatla, Krishna Chaitanya

2014-07-01

16

Distinctive Magneto Conductance and Universal Scaling in One Dimensional Polymer Nanofibers  

NASA Astrophysics Data System (ADS)

The conducting polymers are one dimensional organic hydrocarbon systems where the non-linear local excitations such as solitons, polarons and bipolarons were predicted based on the electron-phonon interactions. The local excitations have different spin-charge relations in different kinds of polymers. In this work, the magneto conductance (MC) of polymer nanofibers is investigated in high magnetic field at low temperature to understand both spin (magneto) and charge (conductance) of the charge carriers simultaneously. We discovered the distinctive zero MC in polyacetylene nanofibers while the finite MC in polyaniline and polythiophene nanofibers. On the other hand, the charge transports of polymer nanofibers as a function of temperature and bias are observed to be scaled onto the universal curve. We conclude that the universal scaling and the zero MC (the finite MC) in polyacetylene (polyaniline and polythiophene) nanofibers are from the interacting spinless charged solitons (interacting polarons which have both spin and charge).

Choi, Ajeong; Kim, Kyung Ho; Hong, Sung Ju; Goh, Munju; Akagi, Kazuo; Kaner, Richard B.; Park, Yung Woo

2012-02-01

17

One-dimensional mu-chloromanganese(II)-tetrathiafulvalene (TTF) coordination compound.  

PubMed

A new tetrathiafulvalene derivative 1 bearing a single pyridine group and its coordination complex 2, with stoichiometry [Mn(mu-Cl)Cl(1)2(CH3OH)]n, have been synthesized and fully characterized. The complex 2 shows an extended chain structure, which is potentially favorable for electrical conductivity. Notably, this is the first monohalogen-bridged Mn(II) polymer exhibiting a moderate antiferromagnetic coupling between the Mn(II) centers. PMID:16602768

Jia, Chunyang; Liu, Shi-Xia; Ambrus, Christina; Neels, Antonia; Labat, Gaël; Decurtins, Silvio

2006-04-17

18

Probing spin-charge relation by magnetoconductance in one-dimensional polymer nanofibers  

NASA Astrophysics Data System (ADS)

Polymer nanofibers are one dimensional (1-D) organic hydrocarbon systems containing conducting polymers where the non-linear local excitations such as solitons, polarons and bipolarons formed by the electron-phonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here we report our observations of a qualitatively different MC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite) MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge).

Park, Yung Woo

2013-03-01

19

Probing spin-charge relation by magnetoconductance in one-dimensional polymer nanofibers  

NASA Astrophysics Data System (ADS)

Polymer nanofibers are one-dimensional organic hydrocarbon systems containing conducting polymers where the nonlinear local excitations such as solitons, polarons, and bipolarons formed by the electron-phonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here, we report our observations of a qualitatively different MC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA, the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite) MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge).

Choi, A.; Kim, K. H.; Hong, S. J.; Goh, M.; Akagi, K.; Kaner, R. B.; Kirova, N. N.; Brazovskii, S. A.; Johnson, A. T.; Bonnell, D. A.; Mele, E. J.; Park, Y. W.

2012-10-01

20

Solitons and polarons in quasi-one dimensional conducting polymers and related materials  

SciTech Connect

In recent years it has become increasingly appreciated that fundamentally nonlinear excitations - solitons - play an essential role in an incredible variety of natural systems. These solitons, which frequently exhibit remarkable stability under interactions and perturbations, often dominate the transport, response, or structural properties of the systems in which they occur. In this article, we present an introduction to the solitons that occur in quasi-one-dimensional conducting polymers (synmetals) and related systems. The relevance of this subject to molecular electronic devices is twofold. First, many of these materials have molecular structures similar to possible prototype molecular switches. Second, to understand in detail how a molecular electronic device could work, it is essential to have a broad perspective on the nature of possible excitations in a variety of natural and synthetic molecular materials. 51 references.

Campbell, D.K.

1983-01-01

21

Hydrogencyanamide-bridged one-dimensional polymers built on Mn(III)-Schiff base fragments: synthesis, structure, and magnetism.  

PubMed

The ability of NCNH(-) to construct transition metal coordination polymers and to transmit magnetic coupling was investigated. By introduction of various tetradentate Schiff base ligands (L) and different solvents (S), nine NCNH(-)-bridged manganese(III) coordination complexes were obtained. Their structures can be divided into three types: I) NCNH-bridged chains built on mononuclear [Mn(III)(L)] units, [Mn(III)(L)(mu(1,3)-NCNH)](n) (L=5-Brsalen (1), 5-Clsalen (2)); II) NCNH-bridged chains built on dinuclear [Mn(III) (2)(L)(2)] units, complexes 3-8, [Mn(III) (2)(L)(2)(mu(1,3)-NCNH)]ClO(4)S (L=salen, 5-Fsalen, 5-Clsalen, 5-OCH(3)salen; S=CH(3)OH or C(2)H(5)OH); III) NCNH-bridged Mn(III) dimers linked by hydrogen bonds into a 1D polymer, {[Mn(III)(3-OCH(3)salen)(H(2)O)](2)(mu(1,3)-NCNH)}ClO(4) x 0.5 H(2)O (9, salen=N,N'-bis(salicylidene)-1,2-diaminoethane). In these complexes, the N[triple chemical bond]C--NH(-) resonance structure dominates the bonding mode of the NCNH(-) ligand adopting the mu(1,3)-bridging mode. Magnetic characterization shows that the asymmetric NCNH(-) bridge transmits antiferromagnetic interaction between Mn(III) ions and often favors the weak ferromagnetism caused by spin canting in these one-dimensional chains. However, these complexes exhibit different magnetic behaviors at low temperatures. PMID:17171734

Yuan, Mei; Zhao, Fei; Zhang, Wen; Pan, Feng; Wang, Zhe-Ming; Gao, Song

2007-01-01

22

Determining the response of infinite, one-dimensional, non-uniform periodic structures by substructuring using waveshape coordinates  

NASA Astrophysics Data System (ADS)

A method is presented for determining the wavenumbers, waveshapes and point receptances for an infinite, one-dimensional, non-uniform periodic structure with distributed periodic attachments or supports. The approach is based on a general theory of harmonic wave propagation in one-dimensional periodic systems. Ill-conditioning was previously reported as an impediment to applying the theory to problems of practical importance. In this paper ill-conditioning problems are overcome and a method of substructuring using waveshape coordinates is presented that dramatically improves computational efficiency. The accuracy and generality of the new method are tested by comparing computed and measured receptances for a typical TGV railway track with UIC60 rail, rail pad, ballast and concrete sleepers. The computed results are found to correlate well with measured data.

Brown, G. P.; Byrne, K. P.

2005-10-01

23

The Scaling Limit of Polymer Pinning Dynamics and a One Dimensional Stefan Freezing Problem  

NASA Astrophysics Data System (ADS)

We consider the stochastic evolution of a 1 + 1-dimensional interface (or polymer) in the presence of a substrate. This stochastic process is a dynamical version of the homogeneous pinning model. We start from a configuration far from equilibrium: a polymer with a non-trivial macroscopic height profile, and look at the evolution of a space-time rescaled interface. In two cases, we prove that this rescaled interface has a scaling limit on the diffusive scale (space rescaled by L in both dimensions and time rescaled by L 2 where L denotes the length of the interface) which we describe. When the interaction with the substrate is such that the system is unpinned at equilibrium, then the scaling limit of the height profile is given by the solution of the heat equation with Dirichlet boundary condition ; when the attraction to the substrate is infinite, the scaling limit is given by a free-boundary problem which belongs to the class of Stefan problems with contracting boundary, also referred to as Stefan freezing problems. In addition, we prove the existence and regularity of the solution to this problem until a maximal time, where the boundaries collide. Our result provides a new rigorous link between Stefan problems and Statistical Mechanics.

Lacoin, Hubert

2014-10-01

24

In situ single-crystal to single-crystal (SCSC) transformation of the one-dimensional polymer catena-poly[[diaqua(sulfato)copper(II)]-?2-glycine] into the two-dimensional polymer poly[?2-glycine-?4-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

2014-11-15

25

Photophysics of quasi-one-dimensional excitons in pi-conjugated polymers and semiconducting single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

In this work we studied the ultrafast dynamics of photoexcitations in pi-conjugated organic semiconductors and semiconducting single-walled carbon nanotubes (S-NTs), using a low-intensity high-repetition rate laser system in the spectral range from 0.13 to 1.05 eV, and high-intensity low-repletion rate laser system in the spectral range from 1.2 to 2.5 eV, in the time domain from 100 fs to 1 ns. We also measured cw photomodulation (PM) spectroscopy of pi-conjugated polymers and photoluminescence (PL) spectra of both polymers and isolated nanotubes. In polymers, we found that excitons are the primary photoexcitations in single polymer chains. However, polarons and polaron pairs may also be photogenerated at early time in films. We consider this process to be extrinsic in nature, namely, dependent on materials properties, temperatures, excitation photon energies, as well as the quality of films. Both annealed and unannealed thin NT films and D2O solutions of isolated NTs were investigated. Various transient photoinduced bleaching (PB) and photoinduced absorption (PA) bands were observed, which also showed photoinduced dichroism and decay together after taking into account the PB spectral shift. The PL emission shows polarization degree. We therefore conclude that the primary photoexcitations in S-NT are excitons that are confined along the NTs. Prom the average PL polarization degree and the transient polarization memory decay, we estimate the PL lifetime in isolated NTs in solution to be of the order of 500 ps, coupling with the minute PL emission quantum efficiency, which indicates weak radiative transition strength. In S-NTs and pi-polymers, the emission spectra relative to the absorption bands are very similar, as well as transient photoinduced absorption bands (PA) with a low-energy PA1 and a higher-energy PA2 in all cases. Theoretical calculations of excited state absorptions within a correlated pi-electron Hamiltonian show the same excitonic energy spectrum, illustrating the universal features of quasi-one-dimensional excitons in carbon-based pi-conjugated systems. In both cases PA1 gives the lower limit of the binding energy of the lowest optical exciton. The binding energy of lowest exciton belonging to the widest S-NTs with diameters ? 1 nm in films is 0.3-0.4 eV, as well as ˜ 0.9 eV in PPV polymers.

Sheng, Chuanxiang

26

A one-dimensional silver(I) coordination polymer based on an asymmetric flexible N-donor carboxylate ligand: catena-poly[(?3-4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoato-?(3)O:O':N(4))silver(I)].  

PubMed

The title compound, [Ag(C15H11N4O2S)]n, was synthesized by the reaction of 4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoic acid (Hptmba) with silver nitrate and triethylamine at room temperature. The asymmetric unit contains one crystallographically independent Ag(I) cation and one ptmba(-) ligand. Each Ag(I) cation is tricoordinated by two carboxylate O atoms and one tetrazole N atom from three different ptmba(-) ligands, displaying a distorted T-shaped geometry. Three Ag(I) cations are linked by tris-monodentate bridging ptmba(-) ligands to form a one-dimensional double chain along the c axis, which is further consolidated by an intrachain ?-? contact with an offset face-to-face distance of 4.176 (3) Å between the centroids of two adjacent aromatic rings in neighbouring benzoate groups. The one-dimensional chains are linked into a three-dimensional supramolecular framework by additional ?-? interchain interactions, viz. of 3.753 (3) Å between two phenyl substituents of the tetrazole rings and of 4.326 (2) Å between a benzoate ring and a tetrazole ring. Thermogravimetric analysis and the fluorescence spectrum of the title compound reveal its good thermal stability and a strong green luminescence at room temperature. PMID:24594720

Zhang, Hai Na; Zhang, Qing Fu; Wang, Jia Jia; Geng, Ai Jing; Zhang, Chong

2014-03-01

27

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

28

A novel one-dimensional Ni(II)Fe(II) polymer containing l3-cyanides: [Ni(cyclen)]2[Fe(CN)6]8H2O  

E-print Network

A novel one-dimensional Ni(II)­Fe(II) polymer containing l3-cyanides: [Ni(cyclen)]2[Fe(CN)6]Á8H2O- dodecane), that consists of [Ni(cyclen)]2 dimers bridged by l3- cyanides from [Fe(CN)6]4� . The NiÁ Á ÁNi metal centers in a m2-fashion: M­C­N­M0 . On the other hand, polymers containing m3- or m4-cyanides

Gao, Song

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

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

PubMed

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%. PMID:23742585

Fang, Cheng; Butler, David Lee

2013-05-01

31

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

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

Porous Phosphorescent Coordination Polymers for Oxygen Sensing  

SciTech Connect

Phosphorescent cyclometalated iridium tris(2-phenylpyridine) derivatives were designed and incorporated into coordination polymers as tricarboxylate bridging ligands. Three different crystalline coordination polymers were synthesized using a solvothermal technique and were characterized using a variety of methods, including single-crystal X-ray diffraction, PXRD, TGA, IR spectroscopy, gas adsorption measurements, and luminescence measurements. The coordination polymer built from Ir[3-(2-pyridyl)benzoate]{sub 3}, 1, was found to be highly porous with a nitrogen BET surface area of 764 m{sup 2}/g, whereas the coordination polymers built from Ir[4-(2-pyridyl)benzoate]{sub 3}, 2 and 3, were nonporous. The {sup 3}MLCT phosphorescence of each of the three coordination polymers was quenched in the presence of O{sub 2}. However, only 1 showed quick and reversible luminescence quenching by oxygen, whereas 2 and 3 exhibited gradual and irreversible luminescence quenching by oxygen. The high permanent porosity of 1 allows for rapid diffusion of oxygen through the open channels, leading to efficient and reversible quenching of the {sup 3}MLCT phosphorescence. This work highlights the opportunity of designing highly porous and luminescent coordination polymers for sensing other important analytes.

Xie, Zhigang; Ma, Liqing; deKrafft, Kathryn E.; Jin, Athena; Lin, Wenbin

2010-01-01

34

Azide-bridged one-dimensional Mn(III) polymers: effects of side group of Schiff base ligands on structure and magnetism.  

PubMed

By changing ancillary tetradentate Schiff base ligands (L), two new one-dimensional azide-bridged manganese(III) coordination complexes [MnIII(L)(mu1,3-N3)]n [L = 5-Fsalen (1), 5-OCH3 (2); salen = N,N'-bis(salicylidene)-1,2-diaminoethane] as well as a mononuclear complex [MnIII(salophen)(N3)] (3) [salophen = N,N'-bis(salicylidene)-o-phenylenediamine] have been successfully obtained. All of them have been structurally and magnetically characterized. In the structures of 1-3 each MnIII ion is in a distorted octahedral geometry with an obvious Jahn-Teller effect, where the tetradentate L ligands all bind in the equatorial mode, whereas in the axial direction, the N3- ion acts as an end-to-end bridge in 1 and 2 while a terminal group in 3 with a methanol molecule at the other end. Magnetic characterization shows that the mu1,3-bridging azide ion proves to mainly transmit antiferromagnetic interaction between MnIII ions, but these three complexes exhibit various magnetic behaviors at low temperatures. Noteworthily, complex 2 behaves as a weak ferromagnet with a relatively large coercive field of 2.3 kOe, much larger than the value reported previously. PMID:18031035

Yuan, Mei; Zhao, Fei; Zhang, Wen; Wang, Zhe-Ming; Gao, Song

2007-12-24

35

A crystalline porous coordination polymer decorated with nitroxyl radicals catalyzes aerobic oxidation of alcohols.  

PubMed

A porous coordination polymer (PCP) has been synthesized employing an organic ligand in which a stable free radical, isoindoline nitroxide, is incorporated. The crystalline PCP possesses one-dimensional channels decorated with the nitroxyl catalytic sites. When O2 gas or air was used as the oxidant, this PCP was verified to be an efficient, recyclable, and widely applicable catalyst for selective oxidation of various alcohols to the corresponding aldehydes or ketones. PMID:24816302

Li, Liangchun; Matsuda, Ryotaro; Tanaka, Iku; Sato, Hiroshi; Kanoo, Prakash; Jeon, Hyung Joon; Foo, Maw Lin; Wakamiya, Atsushi; Murata, Yasujiro; Kitagawa, Susumu

2014-05-28

36

Syntheses, structural analyses and luminescent property of four alkaline-earth coordination polymers  

NASA Astrophysics Data System (ADS)

Four alkaline-earth coordination polymers, [Ba(Pzdc)(H2O)]n (1), [Ba(Pzdc)]n (2), [AgSr(Pzdc)(NO3)(H2O)]n (3), [Ag2Ca(Pzdc)2(H2O)]n (4) (H2Pzdc=2, 3-pyrazinedicarboxylic acid) have been synthesized and characterized by single-crystal X-ray diffraction. Compounds 1 and 2 afford 2D layer networks generated by one-dimensional chains containing the [Ba2O11N] units. Compound 3 is of 2D mixed-metal coordination network formed by one-dimensional chain units, while 4 is of a 3D heterometallic framework. Interestingly, 1 and 2 can undergo reversible SCSC structural transformation upon dehydration/rehydration of coordinated water molecules. In addition, the ?-? stacking interactions dominate fluorescent properties of compounds 1 and 2.

Zhang, Sheng; Qu, Xiao-Ni; Xie, Gang; Wei, Qing; Chen, San-Ping

2014-02-01

37

Synthesis, crystal structure and luminescence properties of lanthanide coordination polymers with a new semirigid bridging thenylsalicylamide ligand  

SciTech Connect

Two new lanthanide coordination polymers based on a semirigid bridging thenylsalicylamide ligand ([Ln{sub 2}L{sub 3}(NO{sub 3}){sub 6}]·(C{sub 4}H{sub 8}O{sub 2}){sub 2}){sub ?} were obtained and characterized by elemental analysis, X-ray diffraction, IR and TGA measurements. The two compounds are isostructure and possess one dimensional trapezoid ladder-like chain built up from the connection of isolated LnO{sub 3}(NO{sub 3}){sub 3} polyhedra (distorted monocapped antisquare prism) through the ligand. The photoluminescence analysis suggest that there is an efficient ligand-to-Ln(III) energy transfer in Tb(III) complex and the ligand is an efficient “antenna” for Tb(III). From a more general perspective, the results demonstrated herein provide the possibility of controlling the formation of the desired lanthanide coordination structure to enrich the crystal engineering strategy and enlarge the arsenal for developing excellent luminescent lanthanide coordination polymers. - Graphical abstract: We present herein one dimensional lanthanide coordination polymers of a new semirigid exo-bidentate ligand which not only display interesting structures but also possess strong luminescence properties. Display Omitted - Highlights: • We present lanthanide coordination polymers of a new semirigid exo-bidentate ligand. • The lanthanide coordination polymers exhibit interesting structures. • The luminescent properties of Tb(III) complexes are discussed in detail.

Song, Xue-Qin, E-mail: songxq@mail.lzjtu.cn; Wang, Li; Zhao, Meng-Meng; Wang, Xiao-Run; Peng, Yun-Qiao; Cheng, Guo-Quan

2013-09-15

38

The One-Dimensional Random Walk  

NSDL National Science Digital Library

Created by authors Gary McGath and Paul Trunfio of Boston University's Center for Polymer Studies, this is the description and instructions for the One-Dimensional Random Walk applet. This Applet relates random coin-flipping to random motion. It strives to show that randomness (coin-flipping) leads to some sort of predictable outcome (the bell-shaped curve).

Mcgath, Gary; Trunfio, Paul

2008-12-30

39

Thin films of coordination polymer magnets.  

PubMed

Many applications of molecule based magnets, whether they are in information storage, displays, or as components in electronic or spintronic devices, will require putting the active materials on a surface or interfacing them with other components. Although there are many examples of molecule-based magnets, the families of tetracyanoethylene (TCNE) based magnets and Prussian-blue analogs possess materials properties that are close to those required for practical applications, and are the most advanced with respect to studies as thin films. This critical review focuses on fabrication and characterization of thin films of TCNE and Prussian-blue analog coordination polymer magnets. Emphasis is on current developments in thin film heterostructures and potential spintronics applications (135 references). PMID:21465059

Talham, Daniel R; Meisel, Mark W

2011-06-01

40

Synthesis, spectral, X-ray diffraction and thermal studies of new ZnII-pyrazine coordination polymers  

NASA Astrophysics Data System (ADS)

Two new zinc(II) coordination polymers with a ?-diketone and N-donor ancillary ligands, [Zn(pyz)(ttfa)2]n (1) and [Zn(pyz)(btfa)2]n (2), (Httfa = 2-thenoyltrifluoroacetone, Hbtfa = benzoyltrifluoroacetone and pyz = pyrazine), have been prepared and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy, and studied by thermal gravimetric analysis as well as single crystal X-ray diffraction. The crystal and molecular structures of 1 and 2 have been solved by X-ray diffraction and they turned out to be one-dimensional polymers with linear dispositions of the metal atoms. These one-dimensional polymers are further connected to form a 3D supramolecular network by CH⋯? (only in 1), CH⋯F, ?-? and interesting H⋯H (only in 2) interactions.

Marandi, Farzin

2014-02-01

41

KBa2InAs3 with Coexisting Monomers of [In2As7]13-and Their One-Dimensional Polymers  

E-print Network

to be a very effective approach in the exploratory studies of heavy main-group elements in their negative of the pure elements. The structure (orthorhombic, Cmc21, Z ) 16, a ) 10.129(2) Ã?, b ) 25.208(4) Ã?, c ) 13.884(3) Ã?) is made of isolated units of [In2As7]13- and a polymer chain of 1 [In2As5]7- made of the same

42

Dynamic self-assembly of coordination polymers in aqueous solution.  

PubMed

The construction of supramolecular polymers has been intensively pursued because the nanostructures formed through weak non-covalent interactions can be triggered by external stimuli leading to smart materials and sensors. Self-assemblies of coordination polymers consisting of metal ions and organic ligands in aqueous solution also provide particular contributions in this area. The main motivation for developing those coordination polymers originates from the value-added combination between metal ions and ligands. This review highlights the recent progress of the dynamic self-assembly of coordination polymers that result from the sophisticated molecular design, towards fabricating stimuli-responsive systems and bio-related materials. Dynamic structural changes and switchable physical properties triggered by various stimuli are summarized. Finally, the outlook for aqueous nanostructures originated from the dynamic self-assembly of coordination polymers is also presented. PMID:24955807

Li, Wen; Kim, Yongju; Li, Jingfang; Lee, Myongsoo

2014-08-01

43

A conducting coordination polymer based on assembled Cu9 cages.  

PubMed

We report on a novel highly semiconducting 1D coordination polymer architecture obtained by the reaction of a Cu(II) salt with 2,2'-dipyridyldisulfide under microwave solvothermal conditions. This reaction proceeds with an unusual C-S and S-S bond cleavage of the 2,2'-dipyridyldisulfide ligand. The unprecedented architecture of this coordination polymer consists of a 1D chain formed by the assembling of Cu9 cluster cages. The electrical conductivity behavior of this novel material suggests new perspectives for the use of coordination polymers as electrical conducting materials. PMID:18817369

Delgado, Salomé; Sanz Miguel, Pablo J; Priego, José L; Jiménez-Aparicio, Reyes; Gómez-García, Carlos J; Zamora, Félix

2008-10-20

44

Hydrothermal synthesis and characterization of ternary lanthanide-2,2?-bipyridine-3,3?-dicarboxylate coordination polymers  

Microsoft Academic Search

Two lanthanide coordination polymers, [{Ln2(bpdc)3(phen)2(H2O)2}·(H2O)6]n (Ln=Dy (1); Ho (2)) were obtained from 2,2?-bipyridine-3,3?-dicarboxylic acid (H2bpdc), 1,10-phenanthroline (phen) and corresponding lanthanide oxides by hydrothermal synthesis. Polymers 1–2 are found to be isostructural. Single-crystal X-ray diffraction shows that 1–2 are all one-dimensional zigzag chain structures and extend to two-dimensional networks through ?–? interactions and hydrogen bonds. Thermogravimetric analysis of 1–2 displays a

Ming Hu; Qing-Lun Wang; Gong-Feng Xu; Gui-Ru Deng; Guang-Ming Yang

2007-01-01

45

Epoxy Polymers Containing Coordinated Rare-Earth Metal Ions  

Microsoft Academic Search

Solid, optically transparent polymers with a high (up to 25 wt %) content of coordination-bound rare-earth elements were prepared by curing glycidyl esters of phosphorus acids with rare-earth metal salts.

L. M. Amirova; V. P. Fomin; R. R. Amirov

2003-01-01

46

Hydrothermal synthesis, crystal structure and photoluminescence of two 1D Zn(II) coordination polymers  

NASA Astrophysics Data System (ADS)

Two new 1D Zn(II) coordination polymers, [Zn(Bript)(phen)] n ( 1) and [Zn(cca)(bimb)] ( 2) (H 2Bript = 4-bromineisophthalic acid; phen = 1,10-phenanthroline; H 2cca = 2-carboxycinnamic acid; bimb = 1,2-bis(imidazol-1'-yl)butane) have been synthesized by hydrothermal reactions and characterized by IR, elemental analysis and X-ray single-crystal analyses. In complex 1, Bript ligands adopt chelate-bridging coordination mode to link Zn(II) ions into a 1D helical ribbon. In complex 2, cca ligands and bimb ligands link Zn(II) ions into two kinds of macro-rings and the two kinds of macro-rings are arrayed alternately into the final 1D double-strand chain. Furtherly, the one-dimensional chains are assembled into three-dimensional networks by ?-? stacking interactions. In addition, the photoluminescent properties of complexes 1 and 2 have also been investigated.

Huang, Yan; Yan, Bing; Shao, Min

2009-02-01

47

Photocatalytic activity of PANI loaded coordination polymer composite materials: Photoresponse region extension and quantum yields enhancement via the loading of PANI nanofibers on surface of coordination polymer  

SciTech Connect

To enhance photocatalytic property of coordination polymer in visible light region, polyaniline (PANI) loaded coordination polymer photocatalyst was synthesized through in-situ chemical oxidation of aniline on the surface of coordination polymer. The photocatalytic activity of PANI loaded coordination polymer composite material for degradation of Rhodamine B (RhB) was investigated. Compared with pure coordination polymer photocatalyst, which can decompose RhB merely under UV light irradiation, PANI loaded coordination polymer photocatalyst displays more excellent photocatalytic activity in visible light region. Furthermore, PANI loaded coordination polymer photocatalyst exhibits outstanding stability during the degradation of RhB. - Graphical abstract: PANI loaded coordination polymer composite material, which displays excellent photocatalytic activity under visible light was firstly synthesized through in-situ chemical oxidation of aniline on surface of coordination polymer. Display Omitted - Highlights: • This PANI loaded coordination polymer composite material represents the first conductive polymer loaded coordination polymer composite material. • PANI/coordination polymer composite material displays more excellent photocatalytic activity for the degradation of MO in visible light region. • The “combination” of coordination polymer and PANI will enable us to design high-activity, high-stability and visible light driven photocatalyst in the future.

Cui, Zhongping; Qi, Ji; Xu, Xinxin, E-mail: xuxx@mail.neu.edu.cn; Liu, Lu; Wang, Yi, E-mail: yiwang67@163.com

2013-09-15

48

Anions behaviors for the dimensionalities of coordination polymers based on poly(imidazole) ligands  

NASA Astrophysics Data System (ADS)

To explore the influence for the dimensionalities of coordination polymers, in presence of different anions with different behaviors, three new coordination polymers with different dimensionalities have been prepared by reacting M2+ (M = Zn or Co) with two structurally related rod-like poly(imidazole) ligands, 1,4-bis(benzoimidazol-1-yl)-phenyl (L1) and 1,4-bis(imidazol-1-yl)-phenyl (L2). Such three new coordination polymers with different architectures, [Zn(L1)(NO3)2]n (1), {[Zn(L2)2]·2BF4·2HCCl3·2H2O}n (2) and [Co(L2)(SO4)]n (3), have been determined by single-crystal X-ray diffraction analysis and characterized by elemental analysis, and IR analysis. Complex 1 is alternative linked by octahedral Zn centers and the ligand L1 to exhibit a one-dimensional (1D) chain structure. However, complexes 2 and 3 both present layered structures contain a similar -L(ligand)-M(metal)-L-M- chain motifs that found in complex 1. In complex 2, each Zn(II) ion is coordinated by four different L2 to form a undulated sheet. Complex 3 also present a undulated sheet structure, however, they were connected by the SO42- group and the L2 ligands, different from only of the L2 ligands in complex 2. The result indicates that the different anions behaviors could be the great influence on the degree of dimensionality of coordination polymers.

Pan, Qinhe; Ma, Hong; Li, Zuo-Xi; Hu, Tong-Liang

2012-03-01

49

Metal-carboxylate coordination polymers with redox-active moiety of tetrathiafulvalene (TTF).  

PubMed

Though numerous metal-organic frameworks or polymers have been reported, the organic building blocks are usually not redox-active. On the other hand, some mono-, di- or tri-nuclear compounds with tetrathiafulvalene (TTF) have been prepared, although little is known about the coordination polymers combined with paramagnetic metals and organic TTF ligands. We report herein a series of coordination polymers of copper(II) and manganese(II) with TTF dicarboxylate ligand (L). Compound 1, [CuL(2,2-bpy)](n), is a one-dimensional (1-D) coordination polymer with five-coordinated square-pyramidal Cu(II) centers. Mn(II) complex 2, [MnL(2,2-bpy)](n), also takes a 1-D structure, showing a double-bridged mode by carboxylate groups. The 4,4-bipyridine compound 3, [MnL(4,4-bpy)(H(2)O)](n)·CH(3)CN, takes a 2-D grid network. A zinc(II) compound 4, [ZnL(4,4-bpy)(H(2)O)](n)·CH(3)CN, isomorphous structure with 3, is also presented. The electrochemical properties of the solid-state compounds were investigated by cyclic voltammetry using surface-modified electrodes. As usually observed in TTF derivatives, two sets of redox-waves were observed. The values of E(1/2)(1) of compounds 1-4 are in the order of 2(Mn) ? 3(Mn) < 1(Cu) < 4(Zn), indicating that the metal coordination can affect the potential shift of the TTF ligand. Weak antiferromagnetic exchanges are observed for compounds 1, 2, and 3. PMID:21283897

Zhu, Qin-Yu; Wang, Jin-Po; Qin, Yu-Rong; Shi, Zheng; Han, Qiong-Hua; Bian, Guo-Qing; Dai, Jie

2011-03-01

50

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

51

Loops in One Dimensional Random Walks  

E-print Network

Distribution of loops in a one-dimensional random walk (RW), or, equivalently, neutral segments in a sequence of positive and negative charges is important for understanding the low energy states of randomly charged polymers. We investigate numerically and analytically loops in several types of RWs, including RWs with continuous step-length distribution. We show that for long walks the probability density of the longest loop becomes independent of the details of the walks and definition of the loops. We investigate crossovers and convergence of probability densities to the limiting behavior, and obtain some of the analytical properties of the universal probability density.

Shay Wolfling; Yacov Kantor

1999-02-01

52

Synthesis and characterization of coordination polymer nanoparticles as radioisotope tracers.  

PubMed

Coordination polymer nanoparticles (NPs) with gamma-emitting nuclide (Au-198), 411keV, 675keV, 822keV and 1087keV were prepared by coordination polymerization of the radioisotope Au(3+) ions and 1,4-bis(imidazole-1-ylmethyl)benzene in an aqueous solution at room temperature for 3h. Here, the radioisotope Au(3+) ions were prepared by dissolution of Au-198 foil, which was prepared by neutron irradiation from the HANARO reactor, in KCN aqueous solution. The successful synthesis of the radioisotope coordination polymer NPs with 5±0.5nm was confirmed via UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDXS), Thermogravimetric analysis (TGA), and Gamma spectroscopy analysis. The synthesized radioisotope coordination polymer NPs can be used as radiotracers in science, engineering, and industrial fields. PMID:24362459

Oh, Min-Seok; Jung, Sung-Hee; Choi, Seong-Ho

2014-02-01

53

Cadmium coordination polymers based on flexible bis(imidazole) ligands: A rare example for doublet of doublet cadmium polyhedron arrangements  

NASA Astrophysics Data System (ADS)

Two one-dimensional (1D) coordination polymers, [{LCd(O2NO)2(DMF)2}2{(LCd(O2NO)2(DMF))(DMF)}2]n (1) and [L?Cd(O2NO)(ONO2)(DMF)2]n (2), having an aryl chromophoric unit and a flexible bis(imidazole) tail, 9,10-bis{(benzimidazol)methyl}anthracene (L) and 1,4-bis{(imidazol)methyl}benzene (L?), with various coordination modes have been obtained. Molecule 1 represents the first structurally characterized one dimensional coordination polymer consisting of both hepta- and octa-coordinated cadmium centers. In 1, two distorted pentagonal bipyramidal Cd(II) centers and two distorted triangular dodecahedral Cd(II) centers are alternately arranged via bridging bidentate N,N-chelating ligand, L. Whereas, a distorted pentagonal bipyramidal Cd(II) center is formed in 2 where the sterically less crowded L? serves as a bridging bidentate N,N-chelating ligand. Furthermore, 1 and 2 have been characterized by elemental analysis, FT-IR, 1H NMR, UV-vis and fluorescent techniques.

Babu, Chatla Naga; Suresh, Paladugu; Sampath, Natarajan; Prabusankar, Ganesan

2014-10-01

54

Mercury(II) bromide/iodide coordination polymers by self-assembly of a long flexible Schiff base ligand  

NASA Astrophysics Data System (ADS)

Two new isostructural mercury(II) coordination polymers with two different counter-ions, [Hg(?-bpen)Br 2] n ( 1) and [Hg(?-bpen)I 2] n ( 2) {bpen = 1,2-bis(4-pyridyl)ethylenediamine), have been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray data diffraction. Bridging by the ligand bpen causes compounds 1 and 2 to form one-dimensional coordination polymers. The thermal stabilities of both compounds were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). CH⋯Br and CH⋯I interactions in the solid state structure and their role in the self-assembly process are discussed.

Mahmoudi, Ghodrat; Morsali, Ali; Zeller, Matthias

2008-03-01

55

Two novel coordination polymers with different molecular tectonics based on zinc nitrate and bisimidazole ligand  

NASA Astrophysics Data System (ADS)

Two new coordination polymers, [Zn(2-mBIM) 2(NO 3) 2(H 2O) 2] n ( 1) and [Zn(BIM) 2(NO 3) 2(H 2O) 2] n (2) (2-mBIM = bis(2-methylimidazol-1-yl)methane, BIM = bis(imidazol-1-yl)-methane), were synthesized by the reactions of Zn(NO 3) 2 with 2-mBIM and BIM ligands. They were characterized by elemental analyses, IR, TGA and X-ray single-crystal diffraction techniques. Each of metal centers in 1 and 2 is coordinated in a slightly distorted tetrahedral geometry by four aromatic nitrogen atoms from four distinct 2-mBIM or BIM ligands, respectively. In compound 1, each pair of neighboring Zn II centers is bridged by two 2-mBIM ligands to form a 16-membered macrometallacyclic structural motif. Each 2-mBIM ligand is coordinated to two Zn II cations and acts as a bridged ligand to form a one-dimensional polymeric cationic chain structure. Compound 2 has a 2D network structure containing 1D channel, thereby each BIM ligand is coordinated to two Zn II cations and thus acts as a bridging ligand. Moreover, each group of four BIM ligands is linked alternatively to each other by four Zn II cations, resulting in a 32-membered macrometallacycle.

Jin, Chuan-Ming; Chen, Zhan-Fen; Sun, Ting-Quan; Hu, Yan-Jun; Hu, Sheng-Li

2008-10-01

56

1D Zigzag Coordination Polymers of Copper(II) and Nickel(II) with Mixed Ligands Syntheses and Structures  

E-print Network

The one-dimensional coordination polymers [Cu(NO3)2(2,2 - bipy)(4,4 -bipy)]n·2nCH3OH (1) and [Ni(tren)(4,4 -bipy)]n- (ClO4)2n (2), have been synthesized by the self-assembly of a copper(II) complex of 2,2 -bipy and a nickel(II) complex of tren with 4,4 -bipy (2,2 -bipy = 2,2 -bipyridine, 4,4 -bipy = 4,4 -bipyridine

Paik Suh, Myunghyun

57

Synthesis, Crystal Structure and Magnetic Properties of a Nickel(II) Coordination Polymer Based the V-Shaped Ligands  

Microsoft Academic Search

\\u000a Abstract  A new nickel(II) coordination polymer, Ni2(DBA)2(BIDPE)2(H2O) (1) (H2DBA = 4,4?-methylenedibenzoic acid and BIDPE = 4,4?-bis(imidazole-l-yl)diphenyl ether), has been prepared by hydrothermal synthesis and structurally characterized by IR, elemental\\u000a analysis, TGA and single crystal X-ray diffraction. Complex 1 features a one-dimensional chain structure based on triply bridged binuclear units, which is further interlinked into a higher-dimensional\\u000a supramolecular framework by intermolecular weak interactions. Variable-temperature magnetic data

Guang-Xiang Liu; Xiao-Chun Zha; Yan Wang; Sadafumi Nishihara; Xiao-Ming Ren

58

Synthesis, structures and luminescence properties of three manganese coordination polymers with bis(1,2,4-triazol-1-ylmethyl)benzene  

Microsoft Academic Search

One-dimensional chain manganese coordination polymers [Mn(mbtz)2(dca)2(H2O)]n (1), [Mn(mbtz)2Cl2]n (2) and [Mn(mbtz)2(NCS)2]n (3) (mbtz=1,3-bis(1,2,4-triazol-1-ylmethyl)benzene, dca=dicyanamide) have been synthesized and characterized. X-ray crystal structure shows that there are two kinds of mbtz ligands in 1. One acts as the bridging (bidentate) coordination mode and shows the anti-conformation. The other shows the terminal (monodentate) coordination mode and exhibits the syn-conformation. The bridging mbtz

Haiyan Ge; Kui Liu; Yuan Yang; Baolong Li; Yong Zhang

2008-01-01

59

{[GdAg 2(dtpa)(H 2O)] · 3H 2O} n : the first 2D Gd–Ag coordination polymer with Ag–Ag interaction  

Microsoft Academic Search

A novel 4d–4f coordination polymer {[GdAg2(dtpa)(H2O)]·3H2O}n (1) (dtpa=diethylenetriamine pentaacetate) was synthesized and characterized by magnetic and EPR studies. Its one-dimensional Gd–Ag ladder-like chains built upon tetranuclear rings are further connected by Ag–O bonds and Ag–Ag interactions to form a lamellar 2D packing.

Bin Zhao; Xiao-Yan Chen; Wen-Zhen Wang; Peng Cheng; Bin Ding; Dai-Zheng Liao; Shi-Ping Yan; Zong-Hui Jiang

2005-01-01

60

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 A novel coordination polymer of mixed-valence copper(I,II) with 4,4A-bipyridine and in situ oxidized frameworks of coordination polymers, based on complexes of transition metals and multifunctional bridging

Li, Jing

61

One- and three-dimensional silver(I)-5-sulfosalicylate coordination polymers having ligand-supported and unsupported argentophilic interactions  

NASA Astrophysics Data System (ADS)

Four new coordination polymers, namely, {Hemim·[Ag(Hssa)(H2O)]}n (1), {[Ag(ina)2 Ag(Hssa)]·CH3OH·H2O}n (2), {[Ag2(Hssa)(dmp)1.5]·2H2O}n (3) and [Ag2(Hssa)(daoc)]n (4) (Hssa: 5-Sulfosalicylate, emim: 2-ethyl-4-methylimidazole, ina: isonicotinamide, dmp: 2,5-dimethylpyrazine and daoc: 1,8-diaminooctane) were synthesized and characterized by IR spectroscopy, elemental analysis, single crystal X-ray diffraction, powder X-ray diffraction (PXRD) and thermal analysis techniques. Complexes 1 and 2 are one-dimensional (1D) coordination polymers while complexes 3 and 4 are three-dimensional (3D) coordination polymers. Complex 3 consists of three dimensional (3D) 3,3,6-c net with 3,3,6T37 topology. Complex 4 exhibits a 2-fold interpenetrating 3D framework with tfc topology. Complexes 1-4 contain ligand-supported (1-3) and unsupported (4) argentophilic Ag⋯Ag interactions. Photoluminescence spectra of the complexes demonstrate that photoluminescent properties may be attributed to intraligand transition of coordinated Hssa ligand.

Ar?c?, Mürsel; Ye?ilel, Okan Zafer; Ye?ilöz, Ye?im; ?ahin, Onur

2014-12-01

62

Syntheses, structures and luminescent properties of three cadmium coordination polymers with 1,3-bis(1,2,4-triazol-1-ylmethyl)benzene  

Microsoft Academic Search

Three cadmium(II) coordination polymers {[Cd(mbtz)2(H2O)2](BF4)2}n (1) [Cd(mbtz)2Cl2]n (2) and [Cd(mbtz)2Br2]n (3) (mbtz=1,3-bis(1,2,4-triazol-1-ylmethyl)benzene) have been synthesized and characterized. In 1, 2 and 3, two mbtz ligands are wrapped around each other and are held together by cadmium(II) atoms to form one-dimensional chain. Two-dimensional hydrogen bonding network of 1 is formed via the hydrogen bonding interactions between the coordination water molecules and

Haiyan Ge; Liyan Wang; Yuan Yang; Baolong Li; Yong Zhang

2008-01-01

63

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

SciTech Connect

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)(H{sub 2}O){sub 2}]{sub n} (3), [Cu(cbop){sub 2}(4,4 Prime -bipy)(H{sub 2}O)]{sub n} (4) (cbop=(S)-N-(4-cyanobenzoic)-5-oxoproline, 4,4 Prime -bipy=4,4 Prime -bipyridine), {l_brace}[Cu(nbop){sub 2}(4,4 Prime -bipy)]{center_dot}4H{sub 2}O{r_brace}{sub n} (5) (nbop=(S)-N-(4-nitrobenzoic)-5-oxoproline), {l_brace}[Cd(nbop){sub 2}(4,4 Prime -bipy)]{center_dot}2H{sub 2}O{r_brace}{sub n} (6), and [Ni(nbop){sub 2}(4,4 Prime -bipy)(H{sub 2}O){sub 2}]{sub 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 Prime -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. - Graphical abstract: Using aminocarboxylate derivates as chiral ligands, five new homochiral coordination polymers possessing second harmonic generation activities have been hydrothermally synthesized. Highlights: Black-Right-Pointing-Pointer Two new chiral aminocarboxylate derivates were firstly synthesized. Black-Right-Pointing-Pointer Five new homochiral metal organic complexes were obtained hydrothermally based on these ligands. Black-Right-Pointing-Pointer Intramolecular amidation was taken place on the aminocarboxylate derivates during the formation of these complexes. Black-Right-Pointing-Pointer In situ amidation may be due to the impact of 4,4 Prime -bipyridine. Black-Right-Pointing-Pointer The homochiral complexes are nonlinear optical active.

Chen Jianshan; Sheng Tianlu; Hu Shengmin; Xiang Shengchang; Fu Ruibiao; Zhu Qilong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Wu Xintao, E-mail: wxt@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2012-08-15

64

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

65

Preparation of Linear ?-Conjugated Coordination Polymers Having Ruthenium(II) Complex in the Main Chain  

Microsoft Academic Search

Soluble p-conjugated coordination polymers having a ruthenium(II) complex in the main chain were prepared from a “soluble metal complex monomer” and a “bridging ligand” via coordination. Refluxing of an ethanol-water suspension containing (4,4'-dinonyl-2,2'-bipyridyl)Ru(III) with 2,3-bis(2'-pyridyl)pyrazine gave the coordination polymer. The resulting polymer was soluble in common organic solvents. The structure was confirmed by uv\\/vis spectra and gpc analysis.

Gen-ichi Konishi; Kensuke Naka; Yoshiki Chujo

1999-01-01

66

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

2014-11-15

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

One dimensional representations in quantum optics  

NASA Technical Reports Server (NTRS)

The possibility of representing the quantum states of a harmonic oscillator not on the whole alpha-plane but on its one dimensional manifolds is considered. It is shown that a simple Gaussian distribution along a straight line describes a quadrature squeezed state while a similar Gaussian distribution along a circle leads to the amplitude squeezed state. The connection between the one dimensional representations and the usual Glauber representation is discussed.

Janszky, J.; Adam, P.; Foldesi, I.; Vinogradov, An. V.

1993-01-01

69

Deformations of one-dimensional block media  

E-print Network

The paper gives a description of wave propagation in discrete-periodic one-dimensional media with block structure. For one-dimensional problems mathematical models are proposed that describe block structures in the form of a mass chain or bars connected by elastic springs and viscous dampers. For these models, the numerical calculations of the parameters of perturbations are obtained as well as asymptotic solutions at large time since the beginning of pulse action. The numerical calculations and analytical solutions are compared.

Aleksandrova, Nadezhda

2014-01-01

70

The one-dimensional hydrogen atom revisited  

Microsoft Academic Search

The one-dimensional Schrodinger hydrogen atom is an interesting mathematical and physical problem for the study of bound states, eigenfunctions, and quantum-degeneracy issues. This one-dimensional physical system has given rise to some intriguing controversy for more than four decades. Presently, still no definite consensus seems to have been reached. We reanalyzed this apparently controversial problem, approaching it from a Fourier-transform representation

Guillermo Palma; Ulrich Raff

2006-01-01

71

New 4,5-dichlorophthalhydrazidate-bridged chained coordination polymers  

SciTech Connect

The hydrothermal self-assemblies of Pb{sup 2+}/Cd{sup 2+} salt, 4,5-dichlorophthalic acid (dcpha), N{sub 2}H{sub 4}.H{sub 2}O together with 1,10-phenanthroline.H{sub 2}O (phen) or 2,2'-bipyridine (bpy) generated two new monoacylhydrazidate-bridged 1-D chained coordination polymers [Pb{sub 2}(DCPTH){sub 4}(phen){sub 2}] 1 and [Cd{sub 3}(DCPTH){sub 2}(dcph){sub 2}(bpy){sub 2}] 2 (DCPTH=4,5-dichlorophthalhydrazidate, dcph=4,5-dichlorophthalate). The monoacylhydrazidate ligand DCPTH originated from the hydrothermal in situ acylation reaction between dcpha and N{sub 2}H{sub 4}.H{sub 2}O. In compound 1, two types of coordination modes for DCPTH are found, which link alternately the Pb(II) centers into a 1-D chain structure of compound 1 with ancillary phen molecules. In compound 2, DCPTH and dcph as the mixed bridges extend the Cd(II) centers into a 1-D chain structure of compound 2 with auxiliary bpy molecules. DCPTH in compound 2 shows a different coordination mode from those observed in compound 1. -- Graphical abstract: By applying the in situ acylation reaction between 4,5-diclorophthalic acid and N{sub 2}H{sub 4}.H{sub 2}O, two 4,5-dichlorophthalhydrazidate-bridged chained compounds [Pb{sub 2}(DCPTH){sub 4}(phen){sub 2}] and [Cd{sub 3}(DCPTH){sub 2}(dcph){sub 2}(bpy){sub 2}] (4,5-dichlorophthalhydrazidate=DCPTH, and dcph=4,5-dichlorophthalate) were hydrothermally synthesized. Display Omitted Research highlights: > In this article, we first reported the preparations and structural characterization of two examples of 4,5-dichlorophthalhydrazidate-bridged chained coordination polymers [Pb{sub 2}(DCPTH){sub 4}(phen){sub 2}] 1 and [Cd{sub 3}(DCPTH){sub 2}(dcph){sub 2}(bpy){sub 2}] 2. 4,5-dichlorophthalhydrazidate derived from the hydrothermal in situ acylation reactions between 4,5-dichlorophthalic acid and N{sub 2}H{sub 4}.H{sub 2}O. > In this article, a simple method to judge whether the polycarboxylic acid precursors have acylated into the acylhydrazidate ligands is introduced. > In this article, DFT calculations were carried out on the excited electronic states of the compounds, the fluorescence emission properties of the compounds have been better understood. > this article, by the structural characterization of the obtained monoacylhydrazidate-containing compounds, the character of the monoacylhydrazidate ligands has been further understood.

Jin, Juan [College of Chemistry and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023 (China); Wu, Di [State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023 (China); Jia, Ming-Jun [Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry, Jilin University, Qianjin Road 2699, Changchun 130012 (China); Peng, Yu [College of Chemistry and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023 (China); Yu, Jie-Hui, E-mail: jiehuiyu@yahoo.com.c [College of Chemistry and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023 (China); State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, Jiangsu 210093 (China); Wang, Yu-Chang [College of Chemistry and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023 (China); Xu, Ji-Qing, E-mail: xjq@mail.jlu.edu.c [College of Chemistry and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023 (China)

2011-03-15

72

New d 10 heterometallic coordination polymers based on compartmental Schiff-base ligands. Synthesis, structure and luminescence  

Microsoft Academic Search

The self-assembly processes between binuclear [Zn2Ln]2+ complex cations and complex anions, [M(CN)2]? [M(I)=Ag(I), Au(I)], generate new one-dimensional (1-D) coordination polymers: 1?[{L1Zn2(?3-OH)}2(H2O){?-[Ag(CN)2]}](ClO4)3 THF 0.5MeOH 1, 1?[{L1Zn2(?3-OH)}2(H2O){?-[Au(CN)2]}](ClO4)3 THF H2O 2, 1?[{L2Zn2(?-OH)}{?-[Ag(CN)2]}][Ag(CN)2] H2O 3 (H2Ln are bicompartmental Schiff-base ligands resulting from condensation reactions between 2,6-diformyl-p-cresol with 2-aminomethyl-pyridine, and 2-aminoethyl-pyridine, respectively). The luminescence properties of the new heterometallic complexes have been investigated.

Gabriela Marinescu; Augustin M. Madalan; Carmen Tiseanu; Marius Andruh

2011-01-01

73

Three cobalt coordination polymers based on bis(1,2,4-triazol-1-ylmethyl)benzene positional isomer ligands and thiocyanate  

Microsoft Academic Search

The reaction of three positional isomer ligands of bis(1,2,4-triazol-1-ylmethyl)benzene and Co(NCS)2 gives three coordination polymers [Co(obtz)2(NCS)2]n (1), [Co(mbtz)2(NCS)2]n (2) and {[Co(bbtz)2(NCS)2]·2DMF}n (3). 1 and 2 are comprised of similar one-dimensional double chains. In 1, each chain forms ?-? stacking interactions with four adjacent chains (two above and two below) to extend to a three-dimensional supramolecular network. 3 is a neutral

Hai-Yan Ge; Yuan Yang; Yan-Feng Peng; Bao-Long Li; Yong Zhang

2012-01-01

74

Synthesis, characterization and property study of new coordination polymers constructed from flexible dicarboxylates and bidentate nitrogen mixed ligands  

NASA Astrophysics Data System (ADS)

Five new coordination polymers, [Cd(1,2'-cy) 0.5(bix)H 2O] n ( 1), [Cd 2(1,2'-cy) 2(1,10'-phen) 2(H 2O) 2] ( 2), {[Co(1,2-cy)(2,2'-bipy)(H 2O) 2]·2H 2O} n ( 3) {[Cd(succ)(1,10'-phen)H 2O]·H 2O} n ( 4), and {[Cd(succ)(2,2'-bipy)H 2O]·2H 2O} n ( 5) (1,2-cy = 4-cyclohexene-1,2-dicarboxylate, succ = succinic acid, bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,10'-phen = 1,10-phenanthroline, 2,2'-bipy = 2,2'-bipyridine), have been synthesized and characterized by single-crystallographic X-ray diffraction. Complex 1 shows a two-dimensional covalent layer structure. Complex 2 exhibits a two-dimensional supramolecular layer network composed from discrete fundamental units. Complex 3 exhibits a one-dimensional covalent chain-like structure, which further extends to a two-dimensional supramolecular structure with hydrogen bonding and ?-? interactions respectively. Complexes 4 and 5 show three-dimensional supramolecular networks composed from one-dimensional chain-like covalent structures. Furthermore, the magnetic property of complex 3 and fluorescent properties of complexes 1, 2, 4 and 5 have also been studied.

Xu, Xinxin; Liu, Xiaoxia; Zhang, Xia; Sun, Ting

2010-03-01

75

Preparation and characterization of ZnS nanocrystal from Zn(II) coordination polymer and ionic liquid  

NASA Astrophysics Data System (ADS)

We report a facile synthesis of spherical ZnS nanocrystals modified with dianion of 3-ferrocenyl-2-crotonic acid (FCA) from one-dimensional (1-D) coordination polymer. Zn(II) coordination polymer has been demonstrated as both precursor and template in the preparation and surface modifications of nanomaterials. Moreover, an ionic liquid 1-butyl-3-methylimidaz-olium tetrafluoroborate ([BMIM]BF 4) solution system has been designed as an assisting template in this experiment. We demonstrate that the 1-D polymeric chain structure is an excellent template for synthesizing organized assemblies of ZnS nanocrystals at low temperatures and ambient atmosphere. From a combination of X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM), the morphology of the synthesized nanocrystals is spherical and with diameters ranging from 40 to 60 nm. The nanocrystals were further examined by FT-IR and UV-visible absorption spectra. In all, we represent a general strategy which is not only environment friendly but also fast and seedless for the preparation of functional nanomaterials.

Yang, Jia Xiang; Wang, Shao Min; Zhao, Xiao Lu; Tian, Yu Peng; Zhang, Sheng Yi; Jin, Bao Kang; Hao, Xiao Peng; Xu, Xian Yun; Tao, Xu Tang; Jiang, Min Hua

2008-09-01

76

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

77

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

78

Solid-state aggregation of metallacyclophane-based Mn(II)Cu(II) one-dimensional ladders.  

PubMed

Two distinct one-dimensional (1) and two-dimensional (2) mixed-metal-organic polymers have been synthesized by using the "complex-as-ligand" strategy. The structure of 1 consists of isolated ladderlike Mn(II)(2)Cu(II)(2) chains separated from each other by neutral Mn(II)(2) dimers, whereas 2 possesses an overall corrugated layer structure built from additional coordinative interactions between adjacent Mn(II)(2)Cu(II)(2) ladders. Interestingly, 1 and 2 show overall ferri- and antiferromagnetic behavior, respectively, as a result of their distinct crystalline aggregation in the solid state. PMID:22708797

Ferrando-Soria, Jesús; Grancha, Thais; Pasán, Jorge; Ruiz-Pérez, Catalina; Cañadillas-Delgado, Laura; Journaux, Yves; Julve, Miguel; Cano, Joan; Lloret, Francesc; Pardo, Emilio

2012-07-01

79

Diorganotin-based coordination polymers derived from sulfonate/phosphonate/phosphonocarboxylate ligands.  

PubMed

The reactions of diorganotin precursors [R(2)Sn(OR(1))(OSO(2)R(1))](n) [R = R(1) = Me (1); R = Me, R(1) = Et (2)] with an equimolar amount of t-butylphosphonic acid (RT, 8-10 h) in methanol result in the formation of identical products, of composition [(Me(2)Sn)(3)(O(3)PBu(t))(2)(O(2)P(OH)Bu(t))(2)](n) (3). On the other hand, a similar reaction of 2, when carried out in dichloromethane, affords [(Me(2)Sn)(3)(O(3)PBu(t))(2)(OSO(2)Et)(2)·MeOH](n) (4). A plausible mechanism implicating the role of solvent in the formation of these compounds has been put forward. In addition, the synthesis of [(Me(2)Sn)(3)(O(3)PCH(2)CH(2)COOMe)(2)(OSO(2)Me)(2)](n) (5) and [R(2)Sn(O(2)P(OH)CH(2)CH(2)COOMe)(OSO(2)R(1))](n) [R = Et, R(1) = Me (6); R = (n)Bu, R(1) = Et (7)] has been achieved by reacting 1 and related diorganotin(alkoxy)alkanesulfonates with 3-phosphonopropionic acid in methanol. The formation of a methylpropionate functionality on the phosphorus center in these structural frameworks results from in situ esterification of the carboxylic group. X-ray crystallographic studies of 1-7 are presented. The structures of 1 and 2 represent one-dimensional (1D) coordination polymers composed of alternate [Sn-O](2) and [Sn-O-S-O](2) cyclic rings formed by ?(2)-alkoxo and sulfonate ligands, respectively. For 3-5 and 7, variable bonding modes of phosphonate and/or sulfonate ligands afford the construction of two- and three-dimensional self-assemblies that are comprised of trinuclear tin entities with an Sn(3)P(2)O(6) core as well as [Sn-O-P-O](2) and/or [Sn-O-S-O](2) rings. The formation of a 1D coordination polymer in 6 is unique in terms of repeating eight-membered cyclic rings containing Sn, O, P, and S heteroatoms. The contribution from hydrogen-bonding interactions is also found to be significant in these structures. PMID:21250679

Shankar, Ravi; Jain, Archana; Kociok-Köhn, Gabriele; Molloy, Kieran C

2011-02-21

80

Chemically tailorable colloidal particles from infinite coordination polymers.  

PubMed

Micrometre- and nanometre-sized particles play important roles in many applications, including catalysis, optics, biosensing and data storage. Organic particles are usually prepared through polymerization of suitable monomers or precipitation methods. In the case of inorganic materials, particle fabrication tends to involve the reduction of a metal salt, or the controlled mixing of salt solutions supplying a metal cation and an elemental anion (for example, S2-, Se2-, O2-), respectively; in some instances, these methods even afford direct control over the shape of the particles produced. Another class of materials are metal-organic coordination polymers, which are based on metal ions coordinated by polydentate organic ligands and explored for potential use in catalysis, gas storage, nonlinear optics and molecular recognition and separations. In a subset of these materials, the use of organometallic complexes as ligands (so-called metalloligands) provides an additional level of tailorability, but these materials have so far not yet been fashioned into nano- or microparticles. Here we show that simple addition of an initiation solvent to a precursor solution of metal ions and metalloligands results in the spontaneous and fully reversible formation of a new class of metal-metalloligand particles. We observe initial formation of particles with diameters of a few hundred nanometres, which then coalesce and anneal into uniform and smooth microparticles. The ease with which these particles can be fabricated, and the ability to tailor their chemical and physical properties through the choice of metal and organic ligand used, should facilitate investigations of their scope for practical applications. PMID:16319888

Oh, Moonhyun; Mirkin, Chad A

2005-12-01

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

A One Dimensional Deterministic Free Boundary Problem  

Microsoft Academic Search

A general one dimensional deterministic inflnite horizon singular optimal control problem with unbounded control set is considered in this paper. Using the dynamic programming approach we prove that the value function is convex, and C1 along the free boundary. Also, we

Frontera Libre; Guillermo Ferreyra; Jesus A. Pascal

2002-01-01

83

Lanthanide coordination polymers: Synthesis, diverse structure and luminescence properties  

NASA Astrophysics Data System (ADS)

The new semirigid exo-bidentate ligand incorporating furfurysalicylamide terminal groups, namely, 1,4-bis{[(2?-furfurylaminoformyl)phenoxyl]methyl}-2,5-bismethylbenzene (L) was synthesized and used as building blocks for constructing lanthanide coordination polymers with luminescent properties. The series of lanthanide nitrate complexes have been characterized by elemental analysis, IR spectroscopy, and X-ray diffraction analysis. The semirigid ligand L, as a bridging ligand, reacts with lanthanide nitrates forming three distinct structure types: chiral noninterpenetrated two-dimensional (2D) honeycomblike (6,3) (hcb, Schläfli symbol 63, vertex symbol 6 6 6) topological network as type I, 1D zigzag chain as type II and 1D trapezoid ladder-like chain as type III. The structural diversities indicate that lanthanide contraction effect played significant roles in the structural self-assembled process. The luminescent properties of EuIII, TbIII and DyIII complexes are discussed in detail. Due to the good match between the lowest triplet state of the ligand and the resonant energy level of the lanthanide ion, the lanthanide ions in EuIII, TbIII and DyIII complexes can be efficiently sensitized by the ligand.

Song, Xue-Qin; Lei, Yao-Kun; Wang, Xiao-Run; Zhao, Meng-Meng; Peng, Yun-Qiao; Cheng, Guo-Quan

2014-10-01

84

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

85

One-dimensional bimetallic cyano complexes with nicotinamide and isonicotinamide ligands  

NASA Astrophysics Data System (ADS)

Two new 1D bimetallic Cu(II)/Ni(II) coordination polymers, {[Cu(NH3)4(?-na)][Ni(CN)4]}n (1) and {[Cu(NH3)2(ina)2Ni(?-CN)2(CN)2]}n (2) (na: nicotinamide, ina: isonicotinamide) have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, elemental, thermal analyses, and single crystal X-ray diffraction techniques. In both of the complexes, Ni(II) ion is four coordinate with four cyanide-carbon atoms in a square-planar geometry. In 1, the [Ni(CN)4]2- ion acts as a counter-ion, whereas it coordinated to the Cu(II) ions as a bridging ligand in 2. In 1 and 2, each Cu(II) ion is coordinated in a distorted octahedral geometry. Single crystal X-ray analysis showed that 1 and 2 exhibit one-dimensional linear chain running along the crystallographic a-axis and b-axis direction, respectively. Adjacent chains are further stacked through intermolecular hydrogen bonding, NH⋯?, CH⋯Ni and Ni⋯? interactions to form 3D supramolecular network.

Gör, Kansu; Kürkçüo?lu, Güne? Süheyla; Ye?ilel, Okan Zafer; Büyükgüngör, Orhan

2014-02-01

86

Different geometrical arrangements in carboxylate coordination polymers of flexible dicarboxylic acid  

SciTech Connect

Dicarboxylate coordination polymers (1-5) of Mn(II), Ni(II), Cu(II), Zn(II) and Cd(II), respectively, derived from (7-carboxymethoxy-naphthalen-2-yloxy)-acetic acid (L{sub 1}H{sub 2}) are synthesized and characterized. Depending on the coordination sites around the metal centers and coordination mode of the ligand, dimensionality of these polymers varies. The dicarboxylates adopt three spatial orientations: in-plane linear coordination, out-of-plane cis coordination and out-of-plane trans coordination mode. Both the cis and trans out-of-plane coordination modes are found to exist only if the ancillary ligand pyridine is coordinated to the metal ion. When the aquoligand coordinates the in-plane linear coordination mode of L{sub 1} predominates. The coordination polymers 4 and 5 show photoluminescence in solution. The dicarboxylate of (5-carboxymethoxy-naphthalen-1-yloxy)-acetic acid (L{sub 2}H{sub 2}) does not form coordination polymer under ambient conditions, but prefers to remain as uncoordinated anion providing hydrophobic confinement to hexa-aquometal(II) cation. Compound 3 crystallizes in P2{sub 1} space group and it shows broadband ultra-violet fluorescence centered at 352.9 nm on focusing 632.8 nm He:Ne laser. - Graphical abstract: Different geometrical arrangements in coordination polymers derived from (7-carboxymethoxy-naphthalen-2-yloxy)-acetic acid of metal ions Mn(II), Ni(II), Cu(II), Zn(II) and Cd(II) are presented. The (5-carboxymethoxy-naphthalen-1-yloxy)-acetic acid led to hexa-aquo cadmium(II) dicarboxylate. Highlights: > Structural and spectroscopic characterizations of five dicarboxylate coordination polymers of (7-carboxymethoxy-naphthalen-2-yloxy)-acetic acid with different metal ions are presented. > Different geometrical arrangements of coordination polymers stabilized in solid state are described. > Photoluminescence properties of the polymers are shown. > NLO property of a copper coordination polymer is described.

Deka, Himangshu; Sarma, Rupam [Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam (India); Kumari, Satchi; Khare, Alika [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam (India); Baruah, Jubaraj B., E-mail: juba@iitg.ernet.in [Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam (India)

2011-07-15

87

One dimensional analysis of inertially confined plasmas  

NASA Astrophysics Data System (ADS)

Energy transfer processes in a thermonuclear plasma including Coulombic phenomena, bremsstrahlung, and Compton scatter are critically reviewed. These processes are incorporated in a three temperature, inertially confined fusion computer simulation which uses a one dimensional, spherical, Lagrangian hydrodynamics scheme. The computer code, still in the validation phase, uses separate subroutines to model hydrodynamics, thermonuclear burn, neutron heating, alpha particle heating, and energy transfer processes in CGS units.

Debruyne, D. A.

1982-03-01

88

One-dimensional gas of hard needles  

E-print Network

We study a one dimensional gas of needle-like objects as a testing ground for a formalism that relates the thermodynamic properties of "hard" potentials to the probabilities for contacts between particles. Specifically, we use Monte Carlo methods to calculate the pressure and elasticity coefficient of the hard-needle gas as a function of its density. The results are then compared to the same quantities obtained analytically from a transfer matrix approach.

Yacov Kantor; Mehran Kardar

2009-02-11

89

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

90

Synthesis, structure and luminescent properties of rare earth coordination polymers constructed from paddle-wheel building blocks.  

PubMed

A series of three-dimensional (3D) novel coordination polymers M(bpdc)1.5(H2O) x 0.5DMF (M = Tb (1), Ho (2), Er (3), or Y (4)) have been synthesized by reaction of the rare earth ions (M3+) with 4,4'-biphenyldicarboxylic acid (H2bpdc) in a mixed solution of DMF and C2H5OH. They possess the same 3D architectures and crystallize in monoclinic space group C2/c. Two seven-coordinated metal centers and four dimonodentate bpdc groups construct a paddle-wheel building block. These building blocks connect with two carboxyl groups to lead to a one-dimensional inorganic chain, ---M-O-C-O-M---, along the [001] direction. The inorganic chains are linked with two biphenyl groups to form 25.15 A x 17.09 A rhombic channels along the c axis without interpenetration. These complexes exhibit strong fluorescence in the visible region, and complex 3 shows Er3+ characteristic emission in the range of 1450-1650 nm at room temperature. These complexes could be anticipated as potential fluorescent probes and an IR-emitter, respectively. PMID:15907110

Guo, Xiaodan; Zhu, Guangshan; Fang, Qianrong; Xue, Ming; Tian, Ge; Sun, Jinyu; Li, Xiaotian; Qiu, Shilun

2005-05-30

91

One-dimensional hypersonic phononic crystals.  

PubMed

We report experimental observation of a normal incidence phononic band gap in one-dimensional periodic (SiO(2)/poly(methyl methacrylate)) multilayer film at gigahertz frequencies using Brillouin spectroscopy. The band gap to midgap ratio of 0.30 occurs for elastic wave propagation along the periodicity direction, whereas for inplane propagation the system displays an effective medium behavior. The phononic properties are well captured by numerical simulations. The porosity in the silica layers presents a structural scaffold for the introduction of secondary active media for potential coupling between phonons and other excitations, such as photons and electrons. PMID:20141118

Gomopoulos, N; Maschke, D; Koh, C Y; Thomas, E L; Tremel, W; Butt, H-J; Fytas, G

2010-03-10

92

Coulomb drag between one-dimensional conductors  

PubMed

We have analyzed Coulomb drag between currents of interacting electrons in two parallel one-dimensional conductors of finite length L attached to external reservoirs. For strong coupling, the relative fluctuations of electron density in the conductors acquire energy gap M. At energies larger than gamma = constxv(-)exp(-LM/v(-))/L+gamma(+), where gamma(+) is the impurity scattering rate, and, for L>v(-)/M, where v(-) is the fluctuation velocity, the gap leads to an "ideal" drag with almost equal currents in the conductors. At low energies the drag is suppressed by coherent instanton tunneling, and the zero-temperature transconductance vanishes, indicating the Fermi-liquid behavior. PMID:11102153

Ponomarenko; Averin

2000-12-01

93

One-dimensional ZnO nanostructures.  

PubMed

The wide-gap semiconductor ZnO with nanostructures such as nanoparticle, nanorod, nanowire, nanobelt, nanotube has high potential for a variety of applications. This article reviews the fundamentals of one-dimensional ZnO nanostructures, including processing, structure, property, application and their processing-microstructure-property correlation. Various fabrication methods of the ZnO nanostructures including vapor-liquid-solid process, vapor-solid growth, solution growth, solvothermal growth, template-assisted growth and self-assembly are introduced. The characterization and properties of the ZnO nanostructures are described. The possible applications of these nanostructures are also discussed. PMID:22905484

Jayadevan, K P; Tseng, T Y

2012-06-01

94

One Dimensional Wave Superposition JS Model  

NSDL National Science Digital Library

The One-Dimensional Wave Function Superposition JavaScript Model shows how the superposition principle gives rise to wave phenomena such as standing waves and beats.  Users enter real-valued wave functions and observe both the time dependent functions and their superposition. This model uses the JavaScript mathematical function parser. The Molecular Dynamics Performance JS Model was developed using the Easy Java Simulations (EJS) version 5. It is distributed as a ready-to-run html page and requires only a browser with JavaScript support.

Christian, Wolfgang; Franciscouembre

2013-09-16

95

A one-dimensional tunable magnetic metamaterial.  

PubMed

We present experimental data on a one-dimensional super-conducting metamaterial that is tunable over a broad frequency band. The basic building block of this magnetic thin-film medium is a single-junction (rf-) superconducting quantum interference device (SQUID). Due to the nonlinear inductance of such an element, its resonance frequency is tunable in situ by applying a dc magnetic field. We demonstrate that this results in tunable effective parameters of our metamaterial consisting of 54 rf-SQUIDs. In order to obtain the effective magnetic permeability ?r,eff from the measured data, we employ a technique that uses only the complex transmission coefficient S??. PMID:24104143

Butz, S; Jung, P; Filippenko, L V; Koshelets, V P; Ustinov, A V

2013-09-23

96

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

97

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

98

Crossover from reptation to Rouse dynamics in a one-dimensional model  

NASA Astrophysics Data System (ADS)

A simple one-dimensional model is constructed for polymer motion. It exhibits the crossover from reptation to Rouse dynamics through gradually allowing hernia creation and annihilation. The model is treated by the density matrix technique which permits an accurate finite-size-scaling analysis of the behavior of long polymers.

Drzewi?ski, Andrzej; van Leeuwen, J. M. J.

2006-06-01

99

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

100

One dimensional spindle titanium oxide nanocrystals.  

PubMed

Anatase TiO2 nanocrystals of 10 nm were formed in aqueous solutions at 90 degrees C for 1 day. The solutions contained ammonium hexafluorotitanate (5 mM) and boric acid (15 mM). The nanocrystals connected each other to form particles of about 100-500 nm. X-ray diffraction, Raman and FT-IR analysis revealed characteristics of the nanocrystals. They had BET surface area of 68 m2/g. Furthermore, morphology was controlled to one dimensional spindle shape by change of supersaturation degree. The spindle nanocrystals of 30 nm in width and 100 nm in length were formed in low concentration solutions. They contained hexafluorotitanate of 0.5 mM and boric acid of 0.15 mM. The spindle nanocrystals had higher crystallinity compared to the above nanocrystals. BET surface area reached 88 m2/g. One dimensional structure was realized by anisotropic crystal growth along c-axis. Low supersaturation degree decreased growth speed and brought out anisotropic crystal growth. PMID:24734718

Masuda, Yoshitake; Kato, Kazumi

2014-04-01

101

Multiple Regulated Assembly, Crystal Structures and Magnetic Properties of Porous Coordination Polymers with Flexible Ligands  

E-print Network

of the lattice water molecules during the heat treatment. Complex 2 can be re- Introduction Porous coordinationFULL PAPER Multiple Regulated Assembly, Crystal Structures and Magnetic Properties of Porous,[c] and Lin-Pei Jin*[a] Keywords: Cobalt / Coordination polymers / Magnetic properties / Nickel / Porous

Gao, Song

102

A click chemistry based coordination polymer inside small heat shock protein.  

PubMed

A branched iron-phenanthroline based coordination polymer has been constructed in a water based system using a click chemistry approach to link monomeric coordination complexes together within a protein cage nanoarchitecture, which acts both as a template and a sized constrained reaction environment. PMID:20024346

Lucon, Janice; Abedin, Md Joynal; Uchida, Masaki; Liepold, Lars; Jolley, Craig C; Young, Mark; Douglas, Trevor

2010-01-14

103

Coordinative nanoporous polymers synthesized with hydrogen-bonded columnar liquid crystals.  

PubMed

In this paper, we report the development of nanoporous polymer which demonstrates the coordination property toward zinc porphyrin. A hydrogen-bonded columnar liquid crystalline precursor composed of a triphenylene template and three equivalent of the surrounding dendric amphiphile bearing a pyridyl head group and a polymerizable aliphatic chain, was covalently fixed by photopolymerization, and then the subsequent selective removal of the template successively resulted in a nanoporous polymer in which the pore wall is modified with pyridyl groups. The nanoporous polymer reflected the conformation of template, and displayed considerable coordination ability of the pyridyl groups towards zinc porphyrin. The coordinative nanoporous polymer is promising as a nano-scaled scaffold for the organization of dyes into functional supramolecular architectures. PMID:23421152

Ishihara, Shinsuke; Furuki, Yusuke; Hill, Jonathan P; Ariga, Katsuhiko; Takeoka, Shinji

2012-10-01

104

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

105

Vanadium polyoxoanion-bridged macrocyclic metal complexes: from one-dimensional to three-dimensional structures.  

PubMed

The reactions of four-coordinated transition metal macrocyclic complexes [ML](ClO(4))(2) (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, M = Ni, Cu) with NH4VO3 under different conditions gave four coordination polymers of {[(CuL)(0.5)(H2L)(1.5)][H2V10O2)] x 6H(2)O}(n) (1x6H(2)O), {[NiL](3)[V16O38(H2O)] x 6H(2)O}(n) (2 x 6H(2)O), {[NiL][VO(3)](2) x 0.33H2O}(n) (3.0.33H(2)O), and {[CuL][VO(3)](2) x 0.33H(2)O}(n) (4 x 0.33H2O). Single crystal X-ray diffraction analyses reveal that four diverse vanadium polyoxoanions, [H2V1oO28)(4-) cluster, [V16O38(H2O)](6-) cage, [V6O18](6-) ring, and [VO(3)](n)(n-) chain, were obtained from the same reactant NH(4)VO(3) under different conditions. In 1, the cluster anion [H2V10O28](4-) alternately bridges [CuL]2+/[H2L]2+ to form a one-dimensional chain, and the [V16O38(H2O)](6-) cage in 2 links three [NiL]2+ into a two-dimensional sheet. Compounds 3 and 4 show three-dimensional structures, which are constructed by the connections of hexanuclear [V6O18](6-) rings with [NiL]2+ in 3 and [VO3](n)(n-) chains with [CuL]2+ in 4, respectively, generating one-dimensional channels occupied by guest water molecules. PMID:19081973

Ou, Guang-Chuan; Jiang, Long; Feng, Xiao-Long; Lu, Tong-Bu

2009-01-01

106

Macroscopic Quantum Tunneling in One Dimensional Superconductor  

NASA Astrophysics Data System (ADS)

Macroscopic quantum tunneling (MQT) in a one dimensional superconductor is discussed based on the microscopic model near the critical temperature. By means of a functional integral approach, a formula for the total decay rate, which is the sum of the thermal activation and quantum mechanical tunneling rate, is derived. The Bounce solution in the imaginary time formalism gives rise to the exponent in the tunneling rate. From the study of fluctuations from the bounce path, the pre-exponential factor has been evaluated. The theory for the tunneling rate is consistent with experimental results for temperatures at which the thermal activation theory fails. As the temperature approaches to the critical temperature, thermal activation over a free energy barrier which separates metastable states is dominant and the theory shows good agreement with experiment over the whole temperature region.

Chang, Yongmin

107

One dimensional M5-brane intersections  

SciTech Connect

We study one-dimensional intersections of M5 branes with M5 and M2 branes. On the worldvolume of the M5-brane, such an intersection appears as a string soliton. We study this worldvolume theory in two different regimes: (1) Where the world-volume theory is formulated in flat space and (2) where the world-volume theory is studied in the supergravity background produced by a stack of M5 (or M2) branes. In both cases, we study the corresponding string solitons, and find the most general BPS configuration consistent with the fraction of supersymmetries preserved. We argue that M5 and M2 brane intersections leave different imprints on the world-volume theory of the intersecting probe brane, although geometrically they appear to be similar.

Fayyazuddin, Ansar [Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States); Department of Physics, Stockholm University, Box 6730, S-113 85 Stockholm (Sweden); Husain, Tasneem Zehra [Department of Physics, Stockholm University, Box 6730, S-113 85 Stockholm (Sweden); Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts (United States); Jatkar, Dileep P. [Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts (United States); Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad, 211019 (India)

2005-05-15

108

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

109

Tellurium-containing polymer micelles: competitive-ligand-regulated coordination responsive systems.  

PubMed

Nanomaterials capable of achieving tunable cargo release kinetics are of significance in a fundamental sense and various biological or medical applications. We report a competitive coordination system based on a novel tellurium-containing polymer and its ligand-regulated release manners. Tellurium was introduced to water-soluble polymers for the first time as drug delivery vehicles. The coordination chemistry between platinum and tellurium was designed to enable the load of platinum-based drugs. Through the competitive coordination of biomolecules, the drugs could be released in a controlled manner. Furthermore, the release kinetics could be modulated by the competitive ligands involved due to their different coordination ability. This tellurium-containing polymer may enrich the family of delivery systems and provide a new platform for future biomedical nanotechnologies. PMID:24605909

Cao, Wei; Gu, Yuwei; Meineck, Myriam; Li, Tianyu; Xu, Huaping

2014-04-01

110

One-dimensional model of inertial pumping.  

PubMed

A one-dimensional model of inertial pumping is introduced and solved. The pump is driven by a high-pressure vapor bubble generated by a microheater positioned asymmetrically in a microchannel. The bubble is approximated as a short-term impulse delivered to the two fluidic columns inside the channel. Fluid dynamics is described by a Newton-like equation with a variable mass, but without the mass derivative term. Because of smaller inertia, the short column refills the channel faster and accumulates a larger mechanical momentum. After bubble collapse the total fluid momentum is nonzero, resulting in a net flow. Two different versions of the model are analyzed in detail, analytically and numerically. In the symmetrical model, the pressure at the channel-reservoir connection plane is assumed constant, whereas in the asymmetrical model it is reduced by a Bernoulli term. For low and intermediate vapor bubble pressures, both models predict the existence of an optimal microheater location. The predicted net flow in the asymmetrical model is smaller by a factor of about 2. For unphysically large vapor pressures, the asymmetrical model predicts saturation of the effect, while in the symmetrical model net flow increases indefinitely. Pumping is reduced by nonzero viscosity, but to a different degree depending on the microheater location. PMID:23496615

Kornilovitch, Pavel E; Govyadinov, Alexander N; Markel, David P; Torniainen, Erik D

2013-02-01

111

One-dimensional zigzag gallium nitride nanostructures  

NASA Astrophysics Data System (ADS)

Two one-dimensional (1D) single-crystalline gallium nitride (GaN) nanostructures with periodic zigzag (type I) and diameter-modulated (type II) shapes have been synthesized by passing through ammonia over a mixture of gallium and gallium oxide (Ga2O3) powders held at elevated temperature. The process was catalyzed by the dispersion of thio-capped Au nanoparticles on the substrate onto which GaN nanostructures were condensed. The transformation between these two nanostructure morphologies was also observed. A possible growth model for the zigzag-shaped nanostructures is proposed, in which the formation of the zigzag nanostructures results from the construction of two different nanoscale unit cells. This work provides an avenue to a group of 1D nanostructures with a zigzag shape. The possibility to form 1D nanostructures yet to be discovered by changing the stacking direction of the (0001) plane will facilitate the fabrication of nanoscale functional devices as well as our understanding of the growth behavior of nanoscale crystallites.

Zhou, X. T.; Sham, T. K.; Shan, Y. Y.; Duan, X. F.; Lee, S. T.; Rosenberg, R. A.

2005-05-01

112

One-dimensional model for microscale shock tube flow  

NASA Astrophysics Data System (ADS)

A one-dimensional model for the numerical simulation of transport effects in small-scale, i.e., low Reynolds number, shock tubes is presented. The conservation equations have been integrated in the lateral directions and three-dimensional effects have been introduced as carefully controlled sources of mass, momentum and energy, into the axial conservation equations. The unsteady flow of gas behind the shock wave is reduced to a quasi-steady flow by choosing a coordinate system attached to the shock. The boundary layer problem is thereby reduced to a laminar solution, similar to the Blasius solution, with the exception that the wall velocity can be nonzero. The resulting one-dimensional equations are then solved numerically using a two-step Lax-Wendroff/ MacCormack scheme with flux correction transport. For validation purposes, comparisons are performed against previously published shock structure and low Reynolds number shock tube experiments; good agreement is observed. The model has been used to predict the performance of a 10µm shock tube and the result of this simulation shows the possibility of shock wave disappearance at lower pressure ratios for a micro-scale shock tube.

Mirshekari, G.; Brouillette, M.

2009-04-01

113

Coordination polymer chains built from Cu(II) and adipate ions linked by hydrogen bonds to form a three-dimensional framework structure.  

PubMed

In the title compound, catena-poly[bis[(2,2'-bipyridine-?(2)N,N')(1,1,3,3-tetracyano-2-ethoxypropenido-?N)copper(II)]-?4-hexanedioato-?(6)O(1),O(1'):O(1):O(6),O(6'):O(6)], [Cu2(C9H5N4O)2(C6H8O4)(C10H8N2)2]n, the adipate (hexanedioate) dianion lies across a centre of inversion in the space group P1. The Cu(II) centre adopts a distorted form of axially elongated (4+2) coordination, and the Cu(II) and adipate components form a one-dimensional coordination polymer from which the 2,2'-bipyridine and 1,1,3,3-tetracyano-2-ethoxypropenide components are pendent, and where each adipate dianion is bonded to four different Cu(II) centres. The coordination polymer chains are linked into a three-dimensional framework structure by a combination of C-H···N and C-H···O hydrogen bonds, augmented by a ?-? stacking interaction. PMID:24992115

Setifi, Zouaoui; Boutebdja, Mehdi; Setifi, Fatima; Merazig, Hocine; Glidewell, Christopher

2014-07-15

114

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

115

Synthesis, crystal structures and properties of a series of three-dimensional lanthanide coordination polymers with the rigid and flexible mixed dicarboxylate ligands of 1,4-benzene dicarboxylic acid and succinic acid  

Microsoft Academic Search

A series of new lanthanide coordination polymers, with the formula [Ln(Suc)0.5(p-BDC)] (Ln=Eu (1), Sm (2), Tb (3), Pr (4), Ho (5); H2Suc=succinic acid; p-H2BDC=1,4-benzene dicarboxylic acid), have been synthesized under hydrothermal condition and all of them have been structurally characterized. X-ray diffraction analyses reveal that complexes 1–5 are isostructural and crystallized in orthorhombic space group Pbca. One-dimensional infinite inorganic edge-sharing

Chun-Guang Wang; Yong-Heng Xing; Zhang-Peng Li; Jing Li; Xiao-Qing Zeng; Mao-Fa Ge; Shu-Yun Niu

2009-01-01

116

First examples of ternary lanthanide 2,2?-bipyridine-3,3?-dicarboxylate coordination polymers with zigzag chains structures assembled from lanthanide ions, 2,2?-bipyridine-3,3?-dicarboxylate and 1,10-phenanthroline  

Microsoft Academic Search

Four lanthanide coordination polymers, [{Ln2(bpdc)3(phen)2(H2O)2}·(H2O)6]n (Ln=Sm (1); Eu (2); Gd (3), Tb (4)), were self-assembled from 2,2?-bipyridine-3,3?-dicarboxylic acid (H2bpdc),1,10-phenanthroline(phen) and corresponding lanthanide oxides by hydrothermal synthesis. Compounds 1–4 are found to be isomorphous and isostructural. Single-crystal X-ray diffraction studies show that compounds 1–4 are all of one-dimensional zigzag chain structures and extend to two-dimensional networks through ?–? interactions and hydrogen

Ming Hu; Qing-lun Wang; Gong-Feng Xu; Gui-Ru Deng; Guang-Ming Yang; Ming Yu; Yan-Hong Zhang

2007-01-01

117

Solid-state polymerization in a polyrotaxane coordination polymer via a [2+2] cycloaddition reaction.  

PubMed

Alternate bpeb ligands in the polyrotaxane 2D coordination polymer [Cd(bpeb)(sdb)]·DMA (1) selectively undergo polymerization via a [2+2] cycloaddition reaction to form a polyrotaxane based 3D structure [Cd(bpeb)0.5(poly-bppcb)0.5(sdb)]·DMA (2) in a single-crystal-to-single-crystal manner. PMID:24823887

Park, In-Hyeok; Medishetty, Raghavender; Lee, Shim Sung; Vittal, Jagadese J

2014-06-25

118

Gas detection by structural variations of fluorescent guest molecules in a flexible porous coordination polymer  

Microsoft Academic Search

The development of a new methodology for visualizing and detecting gases is imperative for various applications. Here, we report a novel strategy in which gas molecules are detected by signals from a reporter guest that can read out a host structural transformation. A composite between a flexible porous coordination polymer and fluorescent reporter distyrylbenzene (DSB) selectively adsorbed CO2 over other

Nobuhiro Yanai; Koji Kitayama; Yuh Hijikata; Hiroshi Sato; Ryotaro Matsuda; Yoshiki Kubota; Masaki Takata; Motohiro Mizuno; Takashi Uemura; Susumu Kitagawa

2011-01-01

119

Photoluminescence of silver(I) and gold(I) cyanide 1D coordination polymers Craig A. Bayse a,  

E-print Network

Photoluminescence of silver(I) and gold(I) cyanide 1D coordination polymers Craig A. Bayse a Keywords: Time-dependent density functional theory Photoluminescence Coinage metal cyanides a b s t r a c t Silver(I) and gold(I) cyanides exist as 1D coordination polymers and are photoluminescent on the edge

Pike, Robert D.

120

Syntheses, crystal structures and properties of two unusual pillared-layer 3d-4f Ln-Cu heterometallic coordination polymers  

SciTech Connect

Two unusual pillared-layer 3d-4f Ln-Cu heterometallic coordination polymers, {l_brace}[Ln{sub 2}Cu{sub 5}Br{sub 4}(IN){sub 7}(H{sub 2}O){sub 6}].H{sub 2}O{r_brace}{sub n} (Ln=Eu (1) and Gd (2), HIN=isonicotinic acid), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, thermal analysis and single-crystal X-ray diffraction. The structure determination reveals that 1 and 2 are isostructural and feature a novel three-dimensional pillared-layer hetrometallic structure built upon the linkages of one-dimensional (1D) linear Ln-carboxylate chains, zero-dimensional (0D) Ln-carboxylate Ln{sub 2}(IN){sub 8} dimers, rare 1D zigzag [Cu{sub 5}Br{sub 4}]{sub n} inorganic chains and IN{sup -} pillars. In both 3D structures, there are Ln-carboxylate layers resulted from the connections of 1D Ln-carboxylate chains and 0D Ln{sub 2}(IN){sub 8} dimers through O-H...O hydrogen bondings. The luminescent properties of 1 have been investigated. The magnetic properties of 1 and 2 have also been studied. - Graphical abstract: Two unusual pillared-layer Eu (Gd)-Cu heterometallic coordination polymers have been hydrothermally synthesized. The luminescent properties of Eu-Cu compound and magnetic properties of both compounds are investigated. Highlights: > Two unusual 3D pillared-layer Eu (Gd)-Cu heterometallic coordination polymers have been synthesized. > 1D and 0D Ln-carboxylate motifs construct layers by O-H...O hydrogen bondings. > In both the structures, there are rare 1D zigzag Cu/Br inorganic chains. > Luminescent properties of Eu-Cu compound and magnetic properties of both the compounds are investigated.

Fan Leqing, E-mail: lqfan@hqu.edu.cn [College of Materials Science and Engineering, Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Xiamen, Fujian 361021 (China); Wu Jihuai, E-mail: jhwu@hqu.edu.cn [College of Materials Science and Engineering, Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Xiamen, Fujian 361021 (China); Huang Yunfang [College of Materials Science and Engineering, Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Xiamen, Fujian 361021 (China)

2011-09-15

121

Multifunctionality of organometallic quinonoid metal complexes: surface chemistry, coordination polymers, and catalysts.  

PubMed

Quinonoid metal complexes have potential applications in surface chemistry, coordination polymers, and catalysts. Although quinonoid manganese tricarbonyl complexes have been used as secondary building units (SBUs) in the formation of novel metal-organometallic coordination networks and polymers, the potentially wider applications of these versatile linkers have not yet been recognized. In this Account, we focus on these diverse new applications of quinonoid metal complexes, and report on the variety of quinonoid metal complexes that we have synthesized. Through the use of [(?(6)-hydroquinone)Mn(CO)3](+), we are able to modify the surface of Fe3O4 and FePt nanoparticles (NPs). This process occurs either by the replacement of oleylamine with neutral [(?(5)-semiquinone)Mn(CO)3] at the NP surface, or by the binding of anionic [(?(4)-quinone)Mn(CO)3](-) upon further deprotonation of [(?(5)-semiquinone)Mn(CO)3] at the NP surface. We have demonstrated chemistry at the intersection of surface-modified NPs and coordination polymers through the growth of organometallic coordination polymers onto the surface modified Fe3O4 NPs. The resulting magnetic NP/organometallic coordination polymer hybrid material exhibited both the unique superparamagnetic behavior associated with Fe3O4 NPs and the paramagnetism attributable to the metal nodes, depending upon the magnetic range examined. By the use of functionalized [(?(5)-semiquinone)Mn(CO)3] complexes, we attained the formation of an organometallic monolayer on the surface of highly ordered pyrolitic graphite (HOPG). The resulting organometallic monolayer was not simply a random array of manganese atoms on the surface, but rather consisted of an alternating "up and down" spatial arrangement of Mn atoms extending from the HOPG surface due to hydrogen bonding of the quinonoid complexes. We also showed that the topology of metal atoms on the surface could be controlled through the use of quinonoid metal complexes. A quinonoid rhodium complex showed catalytic activity in Suzuki-Miyaura type reaction. As a result of the excellent stability of the homogeneous catalyst [(quinone)Rh(COD)](-) in water, we also successfully demonstrated catalyst recycling in 1,2- and 1,4-addition reactions. The compound [(quinone)Ir(COD)](-) showed significantly poorer catalytic activity in 1,4-addition reactions. Following upon the excellent coordination ability of the quinonoid rhodium complexes to metal centers, we synthesized organometallic coordination polymer nanocatalysts and silica gel-supported quinonoid rhodium catalysts, the latter using a surface sol-gel technique. The resulting heterogeneous catalysts showed activity in the stereospecific polymerization of phenylacetylene. PMID:23745596

Kim, Sang Bok; Pike, Robert D; Sweigart, Dwight A

2013-11-19

122

Metal ions and solvents ratio co-regulate four new magnetic coordination polymers based upon an unsymmetric tricarboxylate acid ligand.  

PubMed

Four new coordination polymers (CPs), [Co3(L)2(bib)3(EtOH)2]·2H2O (1), [Mn3(L)2(bib)2(H2O)4]·4H2O (2), [Ni(HL)(bib)(H2O)3] (3) and [Ni3(bib)4(H2O)10]·2(L)·12(H2O) (4), were synthesized under solvothermal conditions with an unsymmetrical tricarboxylic acid ligand [biphenyl-3,3',5-tricarboxylic acid (H3L)] in the presence of the 1,4-bis(1H-imidazol-4-yl)benzene (bib) ligand. In compound 1, tricarboxylate acid ligands (H3L) link Co centers to generate two-dimensional (2D) layers which are further connected by bib ligands to exhibit a three-dimensional (3D) framework with a (4,4,5)-connected (4(2)·6(3)·8)2(4(2)·6(7)·8)2(6(4)·8·10) topology. The three-dimensional (3D) framework of 2 is defined as a (3,3,4)-connected topology with the point symbol of (6·8(2))2(6(2)·8)2(8·10(4)·12). Compound 3 contains a one-dimensional (1D) left-hand helix chain along the a direction and further extends into a 2D supramolecular network and a 3D supramolecular framework via hydrogen bonds. Compound 4 displays a one-dimensional (1D) molecular ladder, which is further combined with each other through ?···? stacking to extend into 2D supramolecular sheets. The supramolecular networks of 3 and 4 resulted from the different solvent ratios [V(H2O)-V(EtOH)] in the reaction. All the CPs are characterized by single-crystal X-ray diffraction analyses, powder X-ray diffraction (PXRD), elemental analyses, IR spectroscopy, and TGA analyses. Moreover, the weak ferromagnetic properties of 2 and 3 and antiferromagnetic properties of 1 and 4 have also been investigated. PMID:24905184

Li, Yuan-Pu; Chai, Ying; Yang, Guo-Ping; Miao, Hui-Hui; Cui, Lin; Wang, Yao-Yu; Shi, Qi-Zhen

2014-07-28

123

Lanthanide coordination polymers based on 5-(2'-carboxylphenyl) nicotinate: syntheses, structure diversity, dehydration/hydration, luminescence and magnetic properties.  

PubMed

Twelve lanthanide coordination polymers associated with the organic ligand 5-(2?-carboxylphenyl) nicotinic acid (H2cpna): {[Ln(Hcpna)(cpna)(phen)]·H2O}n (Ln = Sm (1), Tb (2), Ho (3), phen = 1,10-phenanthroline), {[Sm(Hcpna)(cpna)(phen)]·2H2O}n (4), {[Ln2(cpna)3(H2O)3]·4H2O}n (Ln = Y (5), Tb(6), Dy (7), Ho (8)), [Lu2(cpna)3(H2O)2]n (9), {[Y2(cpna)3(phen)2(H2O)]·H2O}n (10), and [Ln(cpna)(phen)(NO3)]n (Ln = Tm (11), Lu (12)) have been prepared by hydrothermal methods and structurally characterized. The structure analyses reveal that complexes 1–3 are isostructural and possess unique three-dimensional (3D) frameworks based on the dodecanuclear Sm/Tb/Ho macrocycles. Complex 4 exhibits a one-dimensional (1D) wheel-chain structure, which further builds three-dimensional (3D) supramolecular architecture via O–HN hydrogen-bonding interactions. Complexes 5–8 are also isostructural and display three-dimensional (3D) open frameworks, which possess two types of channels along the a- and b-axis, respectively. Complexes 9 and 10 feature three-dimensional (3D) frameworks and are created from tetranuclear and dinuclear units, respectively. Complexes 11 and 12 are isostructural and demonstrate one-dimensional (1D) double chain structures, which further build three-dimensional (3D) supramolecular architecture via C–H···O hydrogen-bonding. The results show that the pH value of the reaction system, anion, auxiliary ligand and lanthanide contraction play a significant role in determining the structures of the complexes. In addition, the results of luminescent measurements for compounds 2 and 6 in the solid state at room temperature indicate that the different types of structures have a dissimilar influence on their characteristic luminescence. The magnetic properties of compounds 1, 3, 4, 7 and 11 have been investigated. Furthermore, thermal stabilities for 1–12 and the dehydration/hydration properties of compound 6 have also been studied. PMID:23364602

Gu, Jin-Zhong; Wu, Jiang; Lv, Dong-Yu; Tang, Yu; Zhu, Kongyang; Wu, Jincai

2013-04-14

124

Sensor applications of one-dimensional nanostructures  

NASA Astrophysics Data System (ADS)

In the first part of the dissertation, changes in the electrical properties of a chemical sensor constructed from mats of GaN nanowires decorated with gold nanoparticles as a function of exposure to Ar, N2 and methane are investigated. The Au nanoparticle-decorated nanowires were found to exhibit chemically selective electrical responses. Compared to vacuum, the sensor exhibited a nominal response to Ar and slightly greater response to N2. Upon exposure to methane the conductivity was suppressed by 50% relative to vacuum. The effect was fully reversible and was independent of exposure history. A model to explain both qualitatively and quantitatively the mechanisms at work within the nanowires that make them sensitive to their environment is developed. It was concluded that using mats of nanowires could be a new and easy method by which to fabricate chemical sensors where the sensor's sensitivity can be determined by either controlling the average size of the nanowires within the mat or the average carrier density. In the second part of this dissertation, the use of carbon nanotubes (CNTs) is explored. The first consists of a model for using CNTs as selective ionic sensors is introduced and calculations of how the current-voltage characteristics change as a function of ion adsorption is presented. It was found that it is possible to predict how changes in the band structure of the CNTs manifest themselves in measurable external electrical parameters, such as conductivity, at room temperature. The mechanism by which the electronic properties are modified is by radial distortion of the nanotube caused by the mutual repulsion of the ions that have been absorbed onto a thin insulating layer of polymer. Depending on the chirality of the nanotube, the radial distortion is found to cause very different types of changes to the current-voltage behavior. For the case of zigzag nanotubes, at fixed bias, the current is found to be strongly modulated as a function of amount of absorbed charge. The second application of CNTs is as directional magnetometers. A model consisting of a complete description of the electronic current in metallic single-walled carbon nanotubes within axially oriented magnetic fields at nonzero temperatures is presented. The goal was to construct a model that used experimentally measurable parameters to predict the actual electrical response of the CNTs. It was found that the current in a zigzag carbon nanotube that is metallic at zero magnetic field is strongly modulated as a function of the magnitude of an axially oriented magnetic field. This property was used as the basis to propose a design of a carbon nanotube based directional magnetometer that could be designed to sense magnetic fields from 1 T to 8 T and at temperatures from 0 K up to 100 K. (Abstract shortened by UMI.)

Dobrokhotov, Vladimir V.

125

Enantioselective synthesis of a chiral coordination polymer with circularly polarized visible laser.  

PubMed

Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL-responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL-induced enantioselective synthesis. By irradiation with either left-handed or right-handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left-handed CPL resulted in crystals with a left-handed helical structure, and right-handed CPL led to crystals with a right-handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers. PMID:25251289

Wu, Shu-Ting; Cai, Zhen-Wen; Ye, Qiao-Yan; Weng, Chen-Hao; Huang, Xi-He; Hu, Xiao-Lin; Huang, Chang-Cang; Zhuang, Nai-Feng

2014-11-17

126

Synthesis, crystal structures and luminescent properties of two 4d-4f Ln-Ag heterometallic coordination polymers based on anion template  

SciTech Connect

Two new 4d-4f Ln-Ag heterometallic coordination polymers, {l_brace}[Ln{sub 3}Ag{sub 5}(IN){sub 10}(H{sub 2}O){sub 7}].4(ClO{sub 4}).4(H{sub 2}O){r_brace}{sub n} (Ln=Eu (1) and Sm (2), HIN=isonicotinic acid), have been synthesized under hydrothermal conditions by reactions of Ln{sub 2}O{sub 3}, AgNO{sub 3}, HIN and HClO{sub 4}, and characterized by elemental analysis, IR, thermal analysis and single-crystal X-ray diffraction. It is proved that HClO{sub 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){sub 2} units. The 2D layers are further interlinked through Ag...Ag and Ag...O(ClO{sub 4}{sup -}) multiple weak interactions, which form a rare Ag-ClO{sub 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. -- Graphical abstract: Two new anion-templated 2D 4d-4f Ln-Ag heterometallic coordination polymers based on novel lanthanide-carboxylate chains and pillared Ag(IN){sub 2} units, {l_brace}[Ln{sub 3}Ag{sub 5}(IN){sub 10}(H{sub 2}O){sub 7}].4(ClO{sub 4}).4(H{sub 2}O){r_brace}{sub n} (Ln=Eu (1) and Sm (2), HIN=isonicotinic acid), have been hydrothermally synthesized and structurally characterized. 1 and 2 exhibit good luminescent properties. Display Omitted Research highlights: > Two 2D Eu (Sm)-Ag coordination polymers templated by perchlorate anion have been synthesized. > Polymers consist of novel 1D lanthanide-carboxylate chains. > In both structures, there are rare Ag...Ag and Ag...O(ClO{sub 4}{sup -}) multiple weak interactions. > Both compounds exhibit good luminescent properties.

Fan, Le-Qing, E-mail: lqfan@hqu.edu.c [Institute of Materials Physical Chemistry, and the Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Quanzhou, Fujian 362021 (China); Chen, Yuan [Institute of Materials Physical Chemistry, and the Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Quanzhou, Fujian 362021 (China); Wu, Ji-Huai, E-mail: jhwu@hqu.edu.c [Institute of Materials Physical Chemistry, and the Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Quanzhou, Fujian 362021 (China); Huang, Yun-Fang [Institute of Materials Physical Chemistry, and the Key Laboratory for Functional Materials of Fujian Higher Education, Huaqiao University, Quanzhou, Fujian 362021 (China)

2011-04-15

127

One-dimensional zinc oxide nanomaterials synthesis and photovoltaic applications  

NASA Astrophysics Data System (ADS)

As humanly engineered materials systems approach the atomic scale, top-down manufacturing approaches breakdown and following nature's example, bottom-up or self-assembly methods have the potential to emerge as the dominant paradigm. Synthesis of one-dimensional nanomaterials takes advantage of such self-assembly manufacturing techniques, but until now most efforts have relied on high temperature vapor phase schemes which are limited in scalability and compatibility with organic materials. The solution-phase approach is an attractive low temperature alternative to overcome these shortcomings. To this end, this thesis is a study of the rationale solution-phase synthesis of ZnO nanowires and applications in photovoltaics. The following thesis goals have been achieved: rationale synthesis of a single ZnO nanowire on a polymer substrate without seeding, design of a wafer-scale technique to control ZnO nanowire array density using layer-by-layer polymers, determination of optimal nanowire field emitter density to maximize the field enhancement factor, design of bridged nanowires across metal electrodes to order to circumvent post-synthesis manipulation steps, electrical characterization of bridged nanowires, rationale solution-phase synthesis of long ZnO nanowires on optical fibers, fabrication of ZnO nanowire dye-sensitized solar cells on optical fibers, electrical and optical characterization of solar cell devices, comparison studies of 2-D versus 3-D nanowire dye-sensitized solar cell devices, and achievement of 6-fold solar cell power conversion efficiency enhancement using a 3-D approach. The thesis results have implications in nanomanufacturing scale-up and next generation photovoltaics.

Weintraub, Benjamin A.

128

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

129

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

130

The effect of amphiphilic polymers on the association, morphology and photophysical properties of hypocrellin coordination polymer/fullerene assemblies.  

PubMed

The yttrium coordination polymer of pyrene modified hypocrellin A (Y(3+)-PyrHA) is synthesized and characterized. The methoxydiglycol malonate modified fullerene can be included in the cavity of Y(3+)-PyrHA in organic solution and buffer solution containing amphiphilic polymers, such as polyvinyl pyrrolidone (PVP), pluronic F127 and P123. The interaction between an amphiphilic polymer and Y(3+)-PyrHA plays an important role in controlling the size and morphology of Y(3+)-PyrHA/fullerene. TEM images of Y(3+)-PyrHA/fullerene in 1% F127 and P123 show nanoparticles in the size range 10-60 nm, while TEM images of Y(3+)-PyrHA/fullerene in 1% PVP display large-scale aggregation. Singlet oxygen is generated by irradiation of the polymer solution of Y(3+)-PyrHA/fullerene in the presence of oxygen. The electron paramagnetic resonance (EPR) spin trapping and 9,10-dimethoxyanthracene-2-sulfonic acid sodium salt (MAS) photooxidation results suggest that in 1% P123 solution Y(3+)-PyrHA/fullerene exhibits a higher singlet oxygen quantum yield than Y(3+)-PyrHA and the corresponding fullerene. PMID:25162985

Ou, Zhize; Liu, Guixia; Gao, Yunyan; Li, Shayu; Li, Huizhen; Li, Yi; Wang, Xuesong; Yang, Guoqiang; Wang, Xin

2014-10-15

131

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

2014-12-01

132

A New Rare-Earth Metal Coordination Polymer Constructed from N -hetero Aromatic Multicarboxylate Ligand  

Microsoft Academic Search

\\u000a Abstract  The hydrothermal reaction of Gd(NO3)3·6H2O with 2,2?-bipyridyl-4,4?-dicarboxylic acid(H2BPDC) ligand results in the formation of a new Gd(III) polymer: {[Gd2(BPDC)3(H2O)3]·H2O}\\u000a n..(1). The central gadolinium ion is coordinated by eight oxygen atoms to give a dicapped triangular prism geometry. Based on\\u000a the versatile coordination modes of BPDC2? ligand, together with hydrogen bonds and ?···? stacking interactions, a 3-D network is presented. DFT

Hai-Jun DongMin; Min Wang; Shu-Wei Huang; Yan-Ling Wu; Hao-Hong Li; Zhi-Rong Chen

2010-01-01

133

Multi-Symplectic Lagrangian, One-Dimensional Gas Dynamics  

E-print Network

The equations of Lagrangian, ideal, one-dimensional (1D), compressible gas dynamics are written in a multi-symplectic form using the Lagrangian mass coordinate $m$ and time $t$ as independent variables, and in which the Eulerian position of the fluid element $x=x(m,t)$ is one of the dependent variables. This approach differs from the Eulerian, multi-symplectic approach using Clebsch variables. Lagrangian constraints are used to specify equations for $x_m$, $x_t$ and $S_t$ consistent with the Lagrangian map, where $S$ is the entropy of the gas. We require $S_t=0$ corresponding to advection of the entropy $S$ with the flow. We show that the Lagrangian Hamiltonian equations are related to the de Donder-Weyl multi-momentum formulation. The pullback conservation laws and the symplecticity conservation laws are discussed. The pullback conservation laws correspond to invariance of the action with respect to translations in time (energy conservation) and translations in $m$ in Noether's theorem. The conservation law due to $m$-translation invariance gives rise to a novel nonlocal conservation law involving the Clebsch variable $r$ used to impose $\\partial S(m,t)/\\partial t=0$. Translation invariance with respect to $x$ in Noether's theorem is associated with momentum conservation. We obtain the Cartan-Poincar\\'e form for the system, and use it to obtain a closed ideal of two-forms representing the equation system.

G. M. Webb

2014-08-18

134

Novel three-dimensional coordination polymers of lanthanides with sulfate and oxydiacetic acid.  

PubMed

Three three-dimensional coordination polymers, viz. poly[[diaqua-?4-oxydiacetato-di-?4-sulfato-dipraseodymium(III)] hemihydrate], [Pr2(C4H4O5)(SO4)2(H2O)2]·0.5H2O, (I), poly[[diaquadi-?3-oxydiacetato-?3-sulfato-dineodymium(III)] 1.32-hydrate], [Nd2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (II), and poly[[diaquadi-?3-oxydiacetato-?3-sulfato-disamarium(III)] 1.32-hydrate], [Sm2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (III), were obtained by hydrothermal reactions of the respective lanthanide oxides and ZnSO4 with oxydiacetic acid (odaH2). The Nd(3+) and Sm(3+) compounds form isomorphous crystal structures in which the lanthanide cations are nine-coordinate, having a tricapped trigonal prismatic coordination. The Pr(3+) compound has an entirely different crystal structure in which two types of coordination polyhedra are observed, viz. nine-coordinate (trigonal prism) and ten-coordinate (bicapped square antiprism). The sulfate anions show various coordination modes, one of which has only rarely been observed crystallographically to date. PMID:24311500

Prasad, Thazhe Kootteri; Rajasekharan, M V

2013-12-15

135

In situ hydrothermal synthesis and structural characterization of two novel Cd II-tetrazole coordination polymers  

NASA Astrophysics Data System (ADS)

The in situ hydrothermal reactions of 4-nitrobenzonitrile with Cd(ClO 4) 2 and CdCl 2 afforded two novel Cd II-tetrazole coordination polymers, 2D network {[Cd(H 2O) 2(4-nptz) 2](H 2O) 2} n ( 1) and 1D double chains [Cd(H 2O) 2(4-nptz) 2] n ( 2). Their synthesis, solid-state structure, and XRPD patterns are reported.

Xiao, Jie; Wang, Wen-Xiang; Lin, Jin-Rui; Zhao, Hong

2009-09-01

136

Order-to-disorder structural transformation of a coordination polymer and its influence on proton conduction.  

PubMed

We observed an ordered-to-disordered structural transformation in a Cu(2+) coordination polymer and investigated its influence on the proton conductivity. The transformation generated highly mobile proton carriers in the structure. The resulting material exhibited a conductivity greater than 10(-2) S cm(-1) at 130 °C. The structural transformation and the conduction mechanism were investigated by EXAFS, TPD-MS and NMR. PMID:25053211

Horike, Satoshi; Chen, Wenqian; Itakura, Tomoya; Inukai, Munehiro; Umeyama, Daiki; Asakura, Hiroyuki; Kitagawa, Susumu

2014-09-14

137

Soluble heterometallic coordination polymers based on a bis-terpyridine-functionalized dioxocyclam ligand.  

PubMed

Soluble homo- and heterometallic coordination polymers containing transition metal cations (Cu(2+), Fe(2+), Co(2+), and Ni(2+) ions) were prepared in a two-step procedure using a polytopic bis(terpyridine)dioxocyclam ligand 1H(2) (dioxocyclam = 1,4,8,11-tetraazacyclotetradecane-5,7-dione). These supramolecular systems incorporate two different metal complexes, the metal cations being located both between two terpyridine units and in the macrocyclic framework. The characterization of these soluble architectures was investigated by cyclic voltammetry, mass spectrometry, viscosimetry, and UV-vis absorption and electron paramagnetic resonance (EPR) spectroscopies. Our results clearly indicate the formation of well-organized heterometallic polymers in which two different metal ions alternate in the self-assembled structure. These investigations furthermore brought to light an original acid-controlled disassembling process of the homometallic copper(II) polymer into dinuclear complexes. PMID:19961146

Gasnier, Aurélien; Barbe, Jean-Michel; Bucher, Christophe; Duboc, Carole; Moutet, Jean-Claude; Saint-Aman, Eric; Terech, Pierre; Royal, Guy

2010-03-15

138

Iron(II) and copper(I) coordination polymers: electrochromic materials with and without chiroptical properties.  

PubMed

The electrochemical and optical properties of films prepared from two different Fe(II) coordination polymers (TPT[Fe(II)TPT](n)(PF(6))(2)(n) (TPT = terpyridine-phenyl-terpyridine) and CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n) (CTPCT = chiral terpyridine-phenyl-chiral terpyridine)) and a coordination polymer based on Cu(I) metal centers (PDP[Cu(I)PDP](n)(BF(4))(n)) (PDP = phenanthroline-dodecane-phenanthroline) have been studied. The oxidation of a PDP[Cu(I)PDP](n)(BF(4))(n) film coated on an indium-tin oxide (ITO) electrode by stepping the potential from 0.0 to +1.4 V vs Ag/AgCl led not only to the complete bleaching of the absorption in the visible region of the spectrum within 5 min but also to a redox-induced dissociation and dissolution of the polymer. The reverse reaction of binding and reassembling the polymer at the electrode surface, upon stepping the potential back to 0.0 V, occurred with a rate which was at least 1 order of a magnitude slower. In contrast, the bis(2,2':6',2' '-terpyridine)iron(II)-based redox polymers TPT[Fe(II)TPT](n)(PF(6))(2)(n) and CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n), during similar spectroelectrochemical experiments, not only exhibited a dramatically enhanced switching rate but also displayed symmetric switching kinetics. The films did not show signs of deterioration over 150 switching cycles. Additionally, in an effort to assemble an electrochromic device with chiroptical properties, the electrochromism of films generated from the enantiomerically pure CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n) polymer was studied through circular dichroism. PMID:12844311

Bernhard, Stefan; Goldsmith, Jonas I; Takada, Kazutake; Abruña, Héctor D

2003-07-14

139

New Inorganic-Organic Coordination Polymers Generated from Rigid or Flexible Bidentate Ligands and Co(NCS) 2· xH 2O  

NASA Astrophysics Data System (ADS)

The coordination chemistry of the long rigid bidentate Schiff-base ligands 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (L1), 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (L2), and of the flexible ligand 1,3-bis(4-pyridyl)propane with Co(NCS) 2· xH 2O has been investigated. Three new coordination polymers were prepared and fully characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. The magnetic behavior of all compounds was also investigated and found to follow the Curie law. [Co(NCS) 2(L1) 2·2CH 2Cl 2] n (1, monoclinic, C2/ m; a= 11.995(2) Å, b=14.596(3) Å, c=10.846(2) Å, ?=110.99(3)°, Z=2) features a two-dimensional non-interpenetrating distorted square pattern. [Co(NCS) 2(L2) 2] n (2, monoclinic, P2 1/ n; a=9.5315(19) Å, b=17.299(4) Å, c=9.6646(19) Å, ?=99.11(3)°, Z=2) features a one-dimensional ring-like chain motif. Important C-H···S hydrogen bonding interactions exist in 2, which play a significant role in aligning the polymer strands in the crystalline solid. [Co(1,3-bis(4-pyridyl)propane) 2(NCS) 2·0.33 H 2O] n (3, monoclinic, P2 1/ n; a=18.701(4) Å, b=16.593(3) Å, c=20.696(4) Å, ?=114.45(3)°, Z=4) exhibits a polymeric pattern similar to that of 1. All three compounds feature similar {CoN 6} pseudooctahedral coordination spheres.

Dong, Yu-Bin; Smith, Mark D.; zur Loye, Hans-Conrad

2000-11-01

140

A three-dimensional cadmium(II) coordination polymer: poly[[[?-4,4'-(propane-1,3-diyl)dipyridine-?(2)N:N](?-3,3'-thiodipropionato-?(3)O,O':O)cadmium(II)] monohydrate].  

PubMed

In the title coordination polymer, {[Cd(C6H8O4S)(C13H14N2)]·H2O}n, the Cd(II) atom displays a distorted octahedral coordination, formed by three carboxylate O atoms and one S atom from three different 3,3'-thiodipropionate ligands, and two N atoms from two different 4,4'-(propane-1,3-diyl)dipyridine ligands. The Cd(II) centres are bridged through carboxylate O atoms of 3,3'-thiodipropionate ligands and through N atoms of 4,4'-(propane-1,3-diyl)dipyridine ligands to form two different one-dimensional chains, which intersect to form a two-dimensional layer. These two-dimensional layers are linked by S atoms of 3,3'-thiodipropionate ligands from adjacent layers to form a three-dimensional network. PMID:24992117

Hao, Xiao-Min; Chen, Gang; Gu, Chang-Sheng; Liu, Ji-Wei

2014-07-15

141

Self-assembly of a mixed-ligand silver-based coordination polymer.  

PubMed

The novel title silver(I) coordination polymer, catena-poly[[acetonitrilesilver(I)]-di-mu-4-[N-(diphenylphosphino)aminomethyl]pyridine-kappa(2)N(1):P;kappa(2)P:N(1)-[acetonitrilesilver(I)]-mu(3)-4-[N,N-bis(diphenylphosphino)aminomethyl]pyridine-kappa(3)N(1):P:P'-bis[acetonitrilesilver(I)(Ag-Ag)]-mu(3)-4-[N,N-bis(diphenylphosphino)aminomethyl]pyridine-kappa(3)P:P':N(1)] tetrakis(tetrafluoroborate) acetonitrile trisolvate], [[Ag(4)(C(2)H(3)N)(4)(C(18)H(17)N(2)P)(2)(C(30)H(26)N(2)P(2))(2)](BF(4))(4).3C(2)H(3)N](n), is formed by the self-assembly of the Ph(2)P(4-NHCH(2)C(5)H(4)N) and (Ph(2)P)(2)(4-NCH(2)C(5)H(4)N) ligands with silver tetrafluoroborate. The polymer consists of alternating rings (which lie about inversion centers) bridged by the pyridyl rings of the bis-phosphine-substituted ligands, with anions hydrogen bonded the length of the chain. Two distinctly different metal coordination environments exist in the polymer, viz. distorted tetrahedral and trigonal geometries. PMID:15528816

Feazell, Rodney P; Carson, Cody E; Klausmeyer, Kevin K

2004-11-01

142

One dimensional time-to-explode (ODTX) in HMX spheres  

SciTech Connect

In a series of papers researchers at Lawrence Livermore National Laboratory (LLNL) have reported measurements of the time to explosion in spheres of various high explosives following a rapid, uniform increase in the surface temperature of the sphere. Due to the spherical symmetry, the time-dependent properties of the explosive (temperature, chemical composition, etc.) are functions of the radial spatial coordinate only; thus the name one-dimensional time-to-explosion (ODTX). The LLNL researchers also report an evolving series of computational modeling results for the ODTX experiments, culminating in those obtained using a sophisticated heat transfer code incorporating accurate descriptions of chemical reaction. Although the chemical reaction mechanism used to describe HMX decomposition is quite simple, the computational results agree very well with the experimental data. In addition to reproducing the magnitude and temperature dependence of the measured times to explosion, the computational results also agree with the results of post reaction visual inspection. The ODTX experiments offer a near-ideal example of a transport process (heat transfer in this case) tightly coupled with chemical reaction. The LLNL computational model clearly captures the important features of the ODTX experiments. An obvious question of interest is to what extent the model and/or its individual components (specifically the chemical reaction mechanism) are applicable to other experimental scenarios. Valid exploration of this question requires accurate understanding of (1) the experimental scenario addressed by the LLNL model and (2) details of the application of the model. The author reports here recent work addressing points (1) and (2).

Breshears, D.

1997-06-02

143

Lanthanide coordination polymer nanoparticles for sensing of mercury(II) by photoinduced electron transfer.  

PubMed

The metal-organic coordination polymers at the nanoscale have emerged as attractive nanomaterials due to their tunable nature. In this work, we for the first time prepared an adenine-based lanthanide coordination polymer nanoparticle (CPNP) with fluorescence sensing function. This kind of CPNP was composed of adenine, terbium ion (Tb(3+)), and dipicolinic acid (DPA) as an auxiliary linking molecule that can sensitize the fluorescence of Tb(3+). The fluorescence of the CPNPs is very weak due to the existence of photoinduced electron transfer (PET) from adenine to DPA, which prevents the intramolecular energy transfer from DPA to Tb(3+), leading to the quench of fluorescence of the CPNPs. In the presence of Hg(2+), however, significant enhancement in the fluorescence of CPNPs was observed because of the suppression of the PET process by the coordination of Hg(2+) with adenine. As a kind of Hg(2+) nanosensor, the CPNPs exhibit excellent selectivity and ultrahigh sensitivity up to the 0.2 nM detection limit. The CPNPs also possess an approximately millisecond-scale-long fluorescence lifetime due to the inclusion of Tb(3+) ions. We envision that the CPNPs could find great potential applications in ultrasensitive time-resolved fluorometric assays and biomedical imaging in the future owing to their long emission lifetimes, excellent dispersion, and stability in aqueous solution. PMID:23121519

Tan, Hongliang; Liu, Baoxia; Chen, Yang

2012-12-21

144

Defect modes in one-dimensional granular crystals  

E-print Network

We study the vibrational spectra of one-dimensional statically compressed granular crystals (arrays of elastic particles in contact) containing light-mass defects. We focus on the prototypical settings of one or two spherical ...

Boechler, Nicholas Sebastian

145

Probabilistic Weights in the One-Dimensional Facility Location Problem  

Microsoft Academic Search

This note deals with the one-dimensional facility location model in which the weights, which can represent either demand volumes or demands and costs combined, are known only probabilistically. The demand points themselves, or at least the \\

George O. Wesolowsky

1977-01-01

146

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

147

Magnetic anisotropy of a one-dimensional electron system  

NASA Astrophysics Data System (ADS)

We have discovered a novel anisotropy in a quasi-one-dimensional electronic system in the presence of a magnetic field. The density of states changes dramatically when a magnetic field is applied along different axes of the sample. Further, we do not observe spin splitting of one-dimensional levels in magnetic fields up to 20 T indicating that enhancement of the Landé g factor is also anisotropic. These results provide new insight into the underlying properties of quantum-confined electrons.

Smith, T. P., III; Brum, J. A.; Hong, J. M.; Knoedler, C. M.; Arnot, H.; Esaki, L.

1988-08-01

148

Structure-borne sound Finite one-dimensional structures  

E-print Network

1 Structure-borne sound · Finite one-dimensional structures »Longitudinal and torsional vibrations x L S Structure-borne sound x L · Finite one-dimensional structures »Longitudinal and torsional vibrations S #12;2 Structure-borne sound · Clamped-free rod, free vibrations n=1 n=2 n=3 v(x) x=0 x

Berlin,Technische Universität

149

Low regularity solutions for the one dimensional Schrodinger equations  

E-print Network

Low regularity solutions for the one dimensional Schr¨odinger equations with derivative Boling Guo: The Cauchy problem for the one dimensional Schr¨odinger equations with derivative vt - ivxx = (|v|2v)x, (x, t of Schr¨odinger equation S(t) = ei t in one spatial dimension satisfies S(t) Xs,b C Hs. (4) t 0 S

150

A multi-functional coordination polymer coexisting spontaneous chirality resolution and weak ferromagnetism  

NASA Astrophysics Data System (ADS)

A multifunctional homochiral coordination polymer, [Co(H2O)(BDC)(4,4?-BPY)]•3H2O (1) (H2BDC=1,2-benzenedicarboxylate and 4,4?-BPY=4,4?-bipyridine), has been successfully isolated from Co(II) ions and mixed ligands (1,2-benzenedicarboxylate and 4,4?-bipyridine). Complex 1, which exhibits spontaneous chirality resolution and weak ferromagnetism, is built by chiral helices interconnected via end-to-end 4,4?-BPY bridges into a two-dimensional (2D) layer structure.

Li, Xiu-Hua; Zhang, Qi; Hu, Ping

2014-10-01

151

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

152

Coronates, spherical containers, bowl-shaped surfaces, porous 1D-, 2D-, 3D-metallo-coordination polymers, and metallodendrimers.  

PubMed

Supramolecular coordination cages and polymers bear exceptional advantages over their organic counterparts. They are available in one-pot reactions and in high yields and display physical properties that are generally inaccessible with organic species. Moreover, their weak, reversible, noncovalent bonding interactions facilitate error checking and self-correction. This review emphasizes the achievements in supramolecular coordination container as well as polymer chemistry initiated by serendipity and their materialization based on rational design. The recognition of similarities in the synthesis of different supramolecular assemblies allows prediction of potential structures in related cases. The combination of detailed symmetry considerations with the basic rules of coordination chemistry has only recently allowed for the design of rational strategies for the construction of a variety of nanosized spherical containers, bowls, 1D-, 2D-, and 3D-coordination polymers with specified size and shape. PMID:22160460

Saalfrank, Rolf W; Scheurer, Andreas

2012-01-01

153

catena-Poly[[[4-amino-3,5-bis(pyridin-2-yl)-4H-1,2,4-triazole-?(2)N(1),N(5)](dicyanamido-?N)copper(II)]-?2-dicyanamido-?(2)N:N']: coordination polymer chains linked into a bilayer by hydrogen bonds and ?-? stacking interactions.  

PubMed

In the title compound, [Cu(C2N3)2(C12H10N6)]n or [Cu(dca)2(abpt)]n, where abpt is 4-amino-3,5-bis(pyridin-2-yl)-4H-1,2,4-triazole and dca is the dicyanamide anion, the Cu(II) centre is five-coordinate with an approximately square-pyramidal geometry. One of the two dicyanamide ligands is a terminal ligand, but the other one acts as a ?1,5-bridging ligand between pairs of Cu(II) centres, so generating a one-dimensional coordination polymer. A combination of N-H···N and C-H···N hydrogen bonds, augmented by ?-? stacking interactions, links the coordination polymer chains into a bilayer structure. Comparisons are made with some related Cu(II) complexes containing dca ligands and heteroaromatic co-ligands. PMID:24705048

Setifi, Zouaoui; Setifi, Fatima; Saadi, Mohamed; Rouag, Djamil Azzeddine; Glidewell, Christopher

2014-04-01

154

Reactions and reactivity of Co-bpdc coordination polymers (bpdc = 4,4'-biphenyldicarboxylate).  

PubMed

By choosing a suitable metal center, ligand, and solvents, we have revealed several structural transformations involving a polymer precursor. infinity 1[Co(bpdc)(H2O)2].H2O (1) was prepared by reaction of Na2bpdc and Co(NO3)2 in aqueous solution. Immersing 1 in pyridine/water solutions of (2:1) and (8:1) ratios yielded a second one-dimensional structure infinity 1[Co(bpdc)(py)2(H2O)2].2py (2) and a two-dimensional structure infinity 2[Co(bpdc)(py)2].H2O (3), respectively. After heating 1 under N2 to remove all water within the structure, the compound Co(bpdc) (IR) was obtained. When IR was immersed in solutions of pyridine/water (5:4) and in pure pyridine (in air), a third one-dimensional structure of infinity 1[Co(bpdc)(py)2(H2O)2].2py.H2O (4) and 3, respectively, were obtained. Compounds 2-4 easily transformed to 1 when immersed in water. Crystal data for 1: monoclinic, space group C2/c with a = 6.950(1), b = 31.585(6), and c = 6.226(1) A, beta = 95.84(3) degrees, Z = 4. Crystal data for 2: triclinic, space group P1 with a = 9.646(2), b = 10.352(2), and c = 17.031(3) A, alpha = 79.02(3) degrees, beta = 86.88(3) degrees, gamma = 77.16(3) degrees, Z = 2. Crystal data for 3: triclinic, space group P1 with a = 9.137(2), b = 10.480(2), and c = 12.254(2) A, alpha = 102.10(3) degrees, beta = 100.80(3) degrees, gamma = 99.43(3) degrees, Z = 2. Crystal data for 4: orthorhombic, space group Pbcn with a = 13.468(3), b = 16.652 (3), and c = 14.977(3) A, Z = 4. PMID:11154590

Pan, L; Ching, N; Huang, X; Li, J

2000-11-13

155

Observation of gas molecules adsorbed in the nanochannels of porous coordination polymers by the in situ synchrotron powder diffraction experiment and the MEM\\/Rietveld charge density analysis  

Microsoft Academic Search

Microporous coordination polymers have attracted attention for their numerous nanotechnology and engineering applications. Nano-coordination space provides some unique properties and functions that could never be realized in conventional porous materials. For the strategy of rational designs and the syntheses of novel porous coordination polymers, the structural information of adsorbed guest molecules inside the nanopores and the host framework is very

Yoshiki Kubota; Masaki Takata; Tatsuo C. Kobayashi; S. Kitagawa

2007-01-01

156

Coordination  

NSDL National Science Digital Library

Coordination is an organized working together of muscles and groups of muscles aimed at bringing about a purposeful movement such as walking or standing. Coordination involves timing and concentration.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-06

157

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

158

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

159

Semiconducting neutral microstructures fabricated by coordinative self-assembly of intramolecular charge-transfer tetrathiafulvalene derivatives.  

PubMed

A new class of tetrathiafulvalene (TTF)-based microstructures fabricated by coordinative self-assembly has been successfully prepared by a solution process. The morphology of the TTF coordination polymers is readily tuned by the variation of metal ions. Upon incorporation of Pb(2+) and Zn(2+) ions, one-dimensional (1D) wirelike microstructures and spherical polymer particles were achieved, respectively. These results indicate that the coordinative approach pursued in this work, in which the building blocks of 1 are linked in a coordination polymer chain by association with metal ions, is an efficient and versatile approach to produce more mechanically robust micro- and nanometer-sized coordination polymer materials. More interestingly, the neutral coordination polymers are conductive and magnetic at room temperature without external manipulation. Such conductivity is reminiscent of the behavior of the neutral conductive TTF in single crystals. PMID:19322846

Geng, Yan; Wang, Xiao-Jun; Chen, Bin; Xue, Hai; Zhao, Yao-Peng; Lee, Shuittong; Tung, Chen-Ho; Wu, Li-Zhu

2009-01-01

160

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

161

Ligand effects on the structural dimensionality and antibacterial activities of silver-based coordination polymers.  

PubMed

Four Ag-based coordination polymers [Ag(Bim)] (1), [Ag2(NIPH)(HBim)] (2), [Ag6(4-NPTA)(Bim)4] (3) and [Ag2(3-NPTA)(bipy)0.5(H2O)] (4) (HBim = 1H-benzimidazole, bipy = 4,4'-bipyridyl, H2NIPH = 5-nitroisophthalic acid, H2NPTA = 3-/4-nitrophthalic acid) have been synthesized by hydrothermal reaction of Ag(i) salts with N-/O-donor ligands. Single-crystal X-ray diffraction indicated that these coordination polymers constructed from mononuclear or polynuclear silver building blocks exhibit three typical structure features from 1-D to 3-D frameworks. These compounds favour a slow release of Ag(+) ions leading to excellent and long-term antimicrobial activities, which is distinguished by their different topological structures, towards both Gram-negative bacteria, Escherichia coli (E. coli) and Gram-positive bacteria, Staphylococcus aureus (S. aureus). In addition, these compounds show good thermal stability and light stability under UV-vis and visible light, which are important characteristics for their further application in antibacterial agents. PMID:24871812

Lu, Xinyi; Ye, Junwei; Sun, Yuan; Bogale, Raji Feyisa; Zhao, Limei; Tian, Peng; Ning, Guiling

2014-07-14

162

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

163

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

164

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

2013-01-01

165

Shock waves in an augmented one-dimensional atom chain  

NASA Astrophysics Data System (ADS)

We derive here a simplified discrete one-dimensional model describing some important features of shock waves. In order to avoid expensive multidimensional simulations, one-dimensional models are commonly used, but the existing ones often exhibit some spurious physically irrelevant behaviour. Here we build a one-dimensional model with perturbations arising from mean higher-dimensional behaviour. The coupling of the system with a deterministic heat bath in the Kac-Zwanzig fashion allows us to derive a generalized Langevin equation for the system, without a priori fixing the temperature in the shocked region. This deterministic problem with several degrees of freedom is then reduced to a simpler stochastic problem with memory. Some numerical results are provided, which illustrate and confirm the qualitative correctness of the model.

Stoltz, G.

2005-09-01

166

Quantum solution for the one-dimensional Coulomb problem  

SciTech Connect

The one-dimensional hydrogen atom has been a much studied system with a wide range of applications. Since the pioneering work of Loudon [R. Loudon, Am. J. Phys. 27, 649 (1959).], a number of different features related to the nature of the eigenfunctions have been found. However, many of the claims made throughout the years in this regard are not correct--such as the existence of only odd eigenstates or of an infinite binding-energy ground state. We explicitly show that the one-dimensional hydrogen atom does not admit a ground state of infinite binding energy and that the one-dimensional Coulomb potential is not its own supersymmetric partner. Furthermore, we argue that at the root of many such false claims lies the omission of a superselection rule that effectively separates the right side from the left side of the singularity of the Coulomb potential.

Nunez-Yepez, H. N.; Salas-Brito, A. L.; Solis, Didier A. [Departamento de Fisica, Universidad Autonoma Metropolitana, Unidad Iztapalapa, Apartado Postal 55-534, Iztapalapa CP 09340 D. F. (Mexico); Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Apartado Postal 21-267, Coyoacan CP 04000 D. F. (Mexico); Facultad de Matematicas, Universidad Autonoma de Yucatan, Periferico Norte Tablaje C. 13615, Merida, Yucatan (Mexico)

2011-06-15

167

One-dimensional action for simplicial gravity in three dimensions  

NASA Astrophysics Data System (ADS)

We present a derivation of the Ponzano-Regge model from a one-dimensional spinor action. The construction starts from the first-order Palatini formalism in three dimensions. We introduce a simplicial decomposition of the three-dimensional manifold and study the discretized action in the spinorial representation of loop gravity. A one-dimensional refinement limit along the edges of the discretization brings us back to a continuum formulation. The three-dimensional action turns into a line integral over the one-skeleton of the simplicial manifold. All fields are continuous but have support only along the one-dimensional edges. We define the path integral and remove the redundant integrals over the local gauge orbits through the usual Faddeev-Popov procedure. The resulting state sum model reproduces the Ponzano-Regge amplitudes.

Wieland, Wolfgang M.

2014-08-01

168

The nature of one-dimensional carbon: polyynic versus cumulenic.  

PubMed

A question of both fundamental as well as practical importance is the nature of one-dimensional carbon, in particular whether a one-dimensional carbon allotrope is polyynic or cumulenic, that is, whether bond-length alternation occurs or not. By combining the concept of aromaticity and antiaromaticity with the rule of Peierls distortion, the occurrence and magnitude of bond-length alternation in carbon chains with periodic boundary conditions and corresponding carbon rings as a function of the chain or ring length can be explained. The electronic properties of one-dimensional carbon depend crucially on the bond-length alternation. Whereas it is generally accepted that carbon chains in the limit of infinite length have a polyynic structure at the minimum of the potential energy surface with bond-length alternation, we show here that zero-point vibrations lead to an effective equalization of all carbon-carbon bond lengths and thus to a cumulenic structure. PMID:24962252

Neiss, Christian; Trushin, Egor; Görling, Andreas

2014-08-25

169

Equilibration of a one-dimensional quantum liquid  

SciTech Connect

We review some of the recent results on equilibration of one-dimensional quantum liquids. The low-energy properties of these systems are described by the Luttinger liquid theory, in which the excitations are bosonic quasiparticles. At low temperatures, the relaxation of the gas of excitations toward full equilibrium is exponentially slow. In electronic Luttinger liquids, these relaxation processes involve backscattering of electrons and give rise to interesting corrections to the transport properties of one-dimensional conductors. We focus on the phenomenological theory of the equilibration of a quantum liquid and obtain an expression for the relaxation rate in terms of the excitation spectrum.

Matveev, K. A., E-mail: matveev@anl.gov [Argonne National Laboratory Argonne, Materials Science Division (United States)

2013-09-15

170

The one-dimensional Hubbard model: A reminiscence  

E-print Network

In 1968 we published the solution of the ground state energy and wave function of the one-dimensional Hubbard model, and we also showed that there is no Mott transition in this model. Details of the analysis have never been published, however. As the Hubbard model has become increasingly important in condensed matter physics, relating to topics such as the theory of high-T_c superconductivity, it is appropriate to revisit the one-dimensional model and to recall here some details of the solution.

E. H. Lieb; F. Y. Wu

2002-07-22

171

Capacitance oscillations in one-dimensional electron systems  

NASA Astrophysics Data System (ADS)

We have made the first capacitance measurements of the density of states of quasi-one-dimensional electronic systems. We observe oscillations reflecting the discrete energy levels of doubly confined electrons squeezed beneath submicron lines (0.2, 0.3, and 0.4 ?m wide) patterned on the surface of GaAs-AlxGa1-xAs heterojunction capacitors. The spacings of the oscillations and their dependence on potential well width can be explained theoretically by quantum-size effects and the quasi-one-dimensional nature of our samples.

Smith, T. P., III; Arnot, H.; Hong, J. M.; Knoedler, C. M.; Laux, S. E.; Schmid, H.

1987-12-01

172

1D + 1D ? 1D polyrotaxane, 2D + 2D ? 3D interpenetrated, and 3D self-penetrated divalent metal terephthalate bis(pyridylformyl)piperazine coordination polymers.  

PubMed

Divalent metal coordination polymers containing terephthalate (tere) and bis(4-pyridylformyl)piperazine (bpfp) show diverse and interesting two-dimensional (2D) interpenetrated, three-dimensional (3D) self-penetrated, or one-dimensional (1D) polyrotaxane topological features. Isostructural {[M(tere)(bpfp)(H(2)O)(2)]•4H(2)O}(n) phases (1, Zn; 2, Co) exhibit mutually inclined 2D + 2D ? 3D interpenetration of gridlike layers. {[Cd(4)(tere)(4)(bpfp)(3)(H(2)O)(2)]·8H(2)O}(n) (3) possesses a novel 3,4,8-connected trinodal self-penetrated network with (4.6(2))(2)(4(2)6(16)8(7)10(3))(4(2)6(4))(2) topology. [Zn(2)Cl(2)(tere)(bpfp)(2)](n) (4) is the first example of a 1D + 1D ? 1D polyrotaxane coordination polymer, to the best of our knowledge. Metal coordination geometry plays a crucial role in dictating the overall dimensionality in this system. Thermal decomposition behavior and luminescent properties of the d(10) configuration metal derivatives are also presented herein. PMID:21776990

Wang, Curtis Y; Wilseck, Zachary M; LaDuca, Robert L

2011-09-19

173

Oxamato-based coordination polymers: recent advances in multifunctional magnetic materials.  

PubMed

The design and synthesis of novel examples of multifunctional magnetic materials based on the so-called coordination polymers (CPs) have become very attractive for chemists and physicists due to their potential applications in nanoscience and nanotechnology. However, their preparation is still an experimental challenge, which requires a deep knowledge of coordination chemistry and large skills in organic chemistry. The recent advances in this field using a molecular-programmed approach based on rational self-assembly methods which fully exploit the versatility of the coordination chemistry of the barely explored and evergreen family of N-substituted aromatic oligo(oxamato) ligands are presented in this feature article. These exploratory studies have revealed a wide variety of interesting multifunctional magnetic materials such as optically-active chiral and luminescent magnets or dynamic porous magnets as candidates for chemical sensing. Our feeling, however, is that we have only scratched the surface of the topic and that there are many more exciting brand-new molecule-based materials waiting to be discovered. PMID:24727906

Grancha, Thais; Ferrando-Soria, Jesús; Castellano, María; Julve, Miguel; Pasán, Jorge; Armentano, Donatella; Pardo, Emilio

2014-07-21

174

Linker-directed vertex desymmetrization for the production of coordination polymers with high porosity.  

PubMed

Five non-interpenetrated microporous coordination polymers (MCPs) are derived by vertex desymmetrization using linkers with symmetry inequivalent coordinating groups, and these MCPs include properties such as rare metal clusters, new network topologies, and supramolecular isomerism. Gas sorption in polymorphic frameworks, UMCM-152 and UMCM-153 (based upon a copper-coordinated tetracarboxylated triphenylbenzene linker), reveals nearly identical properties with BET surface areas in the range of 3300-3500 m(2)/g and excess hydrogen uptake of 5.7 and 5.8 wt % at 77 K. In contrast, adsorption of organosulfur compounds dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) shows remarkably different capacities, providing direct evidence that liquid-phase adsorption is not solely dependent on surface area or linker/metal cluster identity. Structural features present in MCPs derived from these reduced symmetry linkers include the presence of more than one type of Cu-paddlewheel in a structure derived from a terphenyl tricarboxylate (UMCM-151) and a three-bladed zinc paddlewheel metal cluster in an MCP derived from a pentacarboxylated triphenylbenzene linker (UMCM-154). PMID:20839886

Schnobrich, Jennifer K; Lebel, Olivier; Cychosz, Katie A; Dailly, Anne; Wong-Foy, Antek G; Matzger, Adam J

2010-10-01

175

Structural diversity of four novel cadmium coordination polymers constructed by 1,4-bis(imidazol-1-yl)butane and anion ligands  

NASA Astrophysics Data System (ADS)

The reaction of the flexible bis(imidazole) ligand 1,4-bis(imidazol-1-yl)butane (bimb) with corresponding Cd(II) salts (NCS -, dicyanamide (dca), N3-, ClO4-) yields four new coordination polymers, from 1D to 3D networks, namely [Cd(bimb) 2(NCS) 2] n ( 1), [Cd(bimb)(dca) 2] n ( 2), [Cd(bimb)(N 3) 2] n ( 3) and {[Cd(bimb) 3](ClO 4) 2} n ( 4). In 1, each Cd(II) atom links two Cd(II) atoms by double bimb ligands and extends to form an one-dimensional chain structure containing the Cd 2(bimb) 2 22-membered metallocycle. In 2, double ? 1,5-dca bridges connect the Cd(II) atoms to form the zigzag [Cd(dca) 2] n chains and extend through bimb long bridges in four different directions alternatively to construct a novel three-dimensional network. In 3, double end-to-end (EE) and double end-on (EO) azide short bridges alternatively link Cd(II) atoms to form the [Cd(N 3) 2] n chains containing both eight- and four-membered metallocycles which further extend via bimb long bridges in four different directions alternatively to result a three-dimensional network. Compound 4 comprises two equivalent, mutually interpenetrating three-dimensional networks.

Zhang, Yu-Mei; Wang, Li-Yan; Li, Bao-Long; Yang, Jian-Hu; Zhang, Yong

2008-03-01

176

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

177

One-dimensional integral imaging 3D display systems  

Microsoft Academic Search

We have developed several kinds of autostereoscopic display systems using one-dimensional integral imaging method. The integral imaging system reproduces light beams similar of those produced by a real object. Therefore our displays have continuous motion parallax. The design, fabrication, and optical evaluation of the displays have been made. By using our proprietary software, the fast playback of the CG movie

Yuzo Hirayama

2009-01-01

178

Wavelet Analysis of One-Dimensional Cosmological Density Fluctuations  

Microsoft Academic Search

Wavelet analysis is proposed as a new tool for studying the large-scale structure formation of the universe. To reveal its usefulness, the wavelet decomposiiton of a one-dimensional model of cosmological density fluctuations is performed. In contrast with Fourier analysis, the wavelet analysis has the advantage of the ability to retain information concerning location of local density peaks in addition to

Yoshi Fujiwara; Jiro Soda

1996-01-01

179

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

180

Title: Unbiased one dimensional University Ranking application based preference ordering  

E-print Network

level of worldwide reputation. Since no adequate measure of competitiveness of university rankers1 Title: Unbiased one dimensional University Ranking ­ application based preference ordering Authors: András TELCS Professor of Quantitative Methods, University of Pannonia and Assoc. Prof

Telcs, András

181

Random search in the one-dimensional cutting stock problem  

Microsoft Academic Search

The paper reports on a randomized approach to the one-dimensional cutting stock problem. In a sequential heuristic the next pattern to be processed is chosen according to the best outcome of 200 trials of random bin packing. The quality of the solutions is discussed and the problem of multiple occurrence of equivalent solutions with different patterns is explained by the

Richard Vahrenkamp

1996-01-01

182

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

183

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

184

Reflection properties of one dimensional plasma photonic crystal  

NASA Astrophysics Data System (ADS)

In this paper band structure and reflection properties of on one-dimensional plasma photonic crystal (PPC) containing alternate layers of dielectric and micro-plasma have been presented. For the purpose of computation, transfer matrix method has been used. It is found that width of the forbidden band gap(s) can be increased by increasing the thickness of plasma layers.

Kumar, Arun; Khundrakpam, Pinky; Sharma, Priyanka

2013-06-01

185

A closed form network connectivity formula one-dimensional MANETs  

Microsoft Academic Search

In this paper, a closed form network connectivity formula for a one-dimensional mobile ad hoc network (MANET) is developed. Precisely, we derive the probability that a MANET is fully connected given a certain number of nodes randomly and uniformly placed along a path between a source and destination pair. This formula is particularly useful in the process of design and

Chuan Heng Foh; Bu Sung Lee

2004-01-01

186

One-Dimensional Ising Model with "k"-Spin Interactions  

ERIC Educational Resources Information Center

We examine a generalization of the one-dimensional Ising model involving interactions among neighbourhoods of "k" adjacent spins. The model is solved by exploiting a connection to an interesting computational problem that we call ""k"-SAT on a ring", and is shown to be equivalent to the nearest-neighbour Ising model in the absence of an external…

Fan, Yale

2011-01-01

187

One-dimensional wave propagation in particulate suspensions  

NASA Technical Reports Server (NTRS)

One-dimensional small-amplitude wave motion in a two-phase system consisting of an inviscid gas and a cloud of suspended particles is analyzed using a continuum theory of suspensions. Laplace transform methods are used to obtain several approximate solutions. Properties of acoustic wave motion in particulate suspensions are inferred from these solutions.

Rochelle, S. G.; Peddieson, J., Jr.

1976-01-01

188

Physics of quasi one dimensional J.-P. Pouget  

E-print Network

Physics of quasi one dimensional conductors J.-P. Pouget Laboratoire de Physique des Solides, CNRS liquid) behavior; quasi­order at T=0°K (TL and LE liquids) ­ Exact treatment of thermal fluctuations experimental systems · magnetic (AF) chains and ladders · 1D inorganic and organic electronic conductors · edge

Paris-Sud 11, Université de

189

Boundary conditions for one-dimensional Feshbach–Villars equation  

Microsoft Academic Search

We solve the one-dimensional Feshbach–Villars equation for spinless particle subjected to a scalar smooth potential. The wave function is given in terms of the hypergeometric function and via a limiting procedure, the wave functions of the step potential are deduced. Then, the appropriate boundary conditions for the step potential are deduced using the two-component form.

M. Merad; L. Chetouani; A. Bounames

2000-01-01

190

WHYRAC, a new modular one-dimensional exploding wire code  

Microsoft Academic Search

A new one-dimensional code, WHYRAC, intended to provide a comprehensive treatment of exploding wires and wire arrays, is described. The circuit equations treat the wire plasma in an exact way, rather than using a lumped circuit model. Great care has been taken in the Eulerian MHD treatment of plasma motion, resulting in an unusual combination of rapid running capability to

D. G. Colombant; M. Lampe; H. W. Bloomberg

1978-01-01

191

PREMIXED ONE-DIMENSIONAL FLAME (PROF) CODE USER'S MANUAL  

EPA Science Inventory

The report is a user's manual that describes the problems that can be treated by the Premixed One-dimensional Flame (PROF) code. It also describes the mathematical models and solution procedures applied to these problems. Complete input instructions and a description of output ar...

192

Computer solution of one-dimensional Poisson's equation  

Microsoft Academic Search

The one-dimensional Poisson's equation for semiconductors doped with an ion-implanted profile (or any profile) is solved numerically using the mesh method of solution. The original equation is replaced by a set of finite difference equations. Solutions using a uniform mesh distribution together with the Störmer or the Cowell method are described. A variable mesh formulation of both the Störmer and

R. W. Klopfenstein; C. P. Wu

1975-01-01

193

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

194

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

195

Modeling and perception of deformable one-dimensional objects  

Microsoft Academic Search

Recent advances in the modeling of deformable one-dimensional objects (DOOs) such as surgical suture, rope, and hair show significant promise for improving the simulation, perception, and manipulation of such objects. An important application of these tasks lies in the area of medical robotics, where robotic surgical assistants have the potential to greatly reduce surgeon fatigue and human error by improving

Shervin Javdani; Sameep Tandon; Jie Tang; James F. O'Brien; Pieter Abbeel

2011-01-01

196

Phonons in a one-dimensional microfluidic TSEVI BEATUS1  

E-print Network

crystals, formed by the introduction of droplets of immiscible fluid into a liquid-filled channel, provide relations markedly different to those of harmonic crystals, and give rise to a variety of crystalLETTERS Phonons in a one-dimensional microfluidic crystal TSEVI BEATUS1 , TSVI TLUSTY2 AND ROY BAR

Tlusty, Tsvi

197

The Long Decay Model of One-Dimensional Projectile Motion  

ERIC Educational Resources Information Center

This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo ("in De Motu") and by contemporary students. Implications for instruction are…

Lattery, Mark Joseph

2008-01-01

198

Stepwise Nanopore Evolution in One-Dimensional Nanostructures  

E-print Network

) nanostructures such as porous zinc oxide nanorods (ZnONRs), silicon nanowires (SiNWs), and silver nanowires (Ag 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

Cui, Yi

199

One-Dimensional Thermomechanical Constitutive Relations for Shape Memory Materials  

Microsoft Academic Search

The use of the thermoelastic martensitic transformation and its reverse transformation has recently been proposed and demonstrated for several active control ap plications. However, the present constitutive models have lacked several important funda mental concepts that are essential for many of the proposed intelligent material system ap plications such as shape memory hybrid composites.A complete, unified, one-dimensional constitutive model of

C. Liang; C. A. Rogers

1990-01-01

200

Optimal One-Dimensional Relay Placement in Cognitive Radio Networks  

E-print Network

Optimal One-Dimensional Relay Placement in Cognitive Radio Networks Junhua Zhu and Jianwei Huang for a secondary user in a cognitive radio network subject to outage constraints. With selection decode the approximation instead to solve the relay placement problem in cognitive radio networks. We find that the optimal

Huang, Jianwei

201

Asymptotic velocity of one dimensional diffusions with periodic drift  

E-print Network

We consider the asymptotic behaviour of the solution of one dimensional stochastic differential equations and Langevin equations in periodic backgrounds with zero average. We prove that in several such models, there is generically a non vanishing asymptotic velocity, despite of the fact that the average of the background is zero.

P. Collet S. Martinez

2007-05-10

202

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

203

A Short Course on One-Dimensional Random Schrödinger Operators  

E-print Network

We discuss various approaches to localization results for one-dimensional random Schr\\"odinger operators, both discrete and continuum. We focus in particular on the approach based on F\\"urstenberg's Theorem and the Kunz-Souillard method. These notes are based on a series of five one-hour lectures given at University College London in June/July 2011.

David Damanik

2011-07-06

204

A Typed Language for Truthful One-Dimensional Mechanism Design  

E-print Network

A Typed Language for Truthful One-Dimensional Mechanism Design Andrei Lapets Computer Science Dept automatic veri- fication that an algorithm is monotonic and therefore truth- ful. The analysis of truthfulness is accomplished using a syntax-directed transformation which constructs a proof of monotonicity

205

Pyridine-2,4-dicarboxylate: a versatile building block for the preparation of functional coordination polymers.  

PubMed

The hydrothermal reaction of the pyridine-2,4-dicarboxylate (2,4-pdc) dianion with various 3d metal(II) cations resulted in the formation of a series of one-, two- and three-dimensional coordination polymers with varied network topologies. 2,4-pdc reacted directly with MnCI2 or FeCl2 in water at 200 degrees C under mild basic conditions to give a dense three-dimensional polymer, [M(2,4-pdc)] (M = Mn, 1a; M = Fe, 1b), which supports a highly-connected three-dimensional magnetic exchange lattice. Both 1a and 1b undergo antiferromagnetic ordering and the latter Fe(II)-containing material exhibited spin-canting behavior below 6.5 K. Reaction of 2,4-pdc with CoCl2 under identical conditions gave an unusual zigzag chain polymer, [Co4(2,4-pdc)4(OH2)10] (2), that has large amounts of coordinated H2O. The magnetism of 2 based on isolated Co(II) dimers was modeled using a modified van Vleck approach. Adjustment of the reaction pH resulted in the formation of additional Co(II)-containing materials with strongly contrasting structures: at lower pH in the presence of oxalic acid, the same reaction components gave a protonated molecular species, [Co(2,4-pdcH)2(OH2)2]. 2H2O (3); at higher pH in the presence of excess hydroxide, a highly porous, three-dimensional material was obtained, [Co3(micro3-OH)2(2,4-pdc)2] x 9H2O (4a). 4a contains cobalt hydroxide chains, whose magnetic behavior has been studied in detail by neutron diffraction. A Ni(II)-containing analogue was also prepared using NiCI2 (4b), which shows weak antiferromagnetic coupling. Attempts to obtain a Zn(II)-based analogue of the porous material 4 gave instead a unique coordination material, [Zn(micro2-OH)2(2,4-pdc)] (5), which contains uncommon zinc hydroxide bridging modes. PMID:20352809

Humphrey, Simon M; Weldon, Gerald F; Wood, Paul T

2010-01-01

206

Synthesis, crystal structures and properties of a series of three-dimensional lanthanide coordination polymers with the rigid and flexible mixed dicarboxylate ligands of 1,4-benzene dicarboxylic acid and succinic acid  

NASA Astrophysics Data System (ADS)

A series of new lanthanide coordination polymers, with the formula [Ln(Suc) 0.5( p-BDC)] (Ln = Eu ( 1), Sm ( 2), Tb ( 3), Pr ( 4), Ho ( 5); H 2Suc = succinic acid; p-H 2BDC = 1,4-benzene dicarboxylic acid), have been synthesized under hydrothermal condition and all of them have been structurally characterized. X-ray diffraction analyses reveal that complexes 1- 5 are isostructural and crystallized in orthorhombic space group Pbca. One-dimensional infinite inorganic edge-sharing polyhedra chains formed by lanthanide ions and tetradentate carboxyl groups of succinic acid ligands, link to each other through the carbon atoms of succinic acid ligands and phenyl groups of the 1,4-benzene dicarboxylic acid ligands, to lead to a three-dimensional framework structure. In addition, the phase purities of the bulk samples were identified by X-ray powder diffraction. The photoluminescent properties of 1 and 3 were discussed in detail.

Wang, Chun-Guang; Xing, Yong-Heng; Li, Zhang-Peng; Li, Jing; Zeng, Xiao-Qing; Ge, Mao-Fa; Niu, Shu-Yun

2009-03-01

207

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

208

Amine-responsive adaptable nanospaces: fluorescent porous coordination polymer for molecular recognition.  

PubMed

Flexible and dynamic porous coordination polymers (PCPs) with well-defined nanospaces composed of chromophoric organic linkers provide a scaffold for encapsulation of versatile guest molecules through noncovalent interactions. PCPs thus provide a potential platform for molecular recognition. Herein, we report a flexible 3D?supramolecular framework {[Zn(ndc)(o-phen)]?DMF}n (o-phen=1,10-phenanthroline, ndc=2,6-napthalenedicarboxylate) with confined nanospaces that can accommodate different electron-donating aromatic amine guests with selective turn-on emission signaling. This system serves as a molecular recognition platform through an emission-readout process. Such unprecedented tunable emission with different amines is attributed to its emissive charge-transfer (CT) complexation with o-phen linkers. In certain cases this CT emission is further amplified by energy transfer from the chromophoric linker unit?ndc, as evidenced by single-crystal X-ray structural characterization. PMID:25213865

Haldar, Ritesh; Matsuda, Ryotaro; Kitagawa, Susumu; George, Subi J; Maji, Tapas Kumar

2014-10-27

209

Synthesis, structure and characterization of new 1D and 2D Ni(II) coordination polymers  

NASA Astrophysics Data System (ADS)

Two new Ni(II) coordination polymers, namely [Ni 3(Hsdac) 2(sdac) 2(2,2'-bipy) 2] ( 1) and [Ni 2(sdac) 2(4,4'-bipy) 2]·2H 2O ( 2) (sdba = 4,4'-sulfonyldibenzoate, 2,2'-bipy = 2,2'-bipyridine, 4,4'-bipy = 4,4'-bipyridine), have been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses. Compound 1 possesses an interesting chain structure. Adjacent chains are further linked through H-bond interactions between Hsdac ligands to give a two-dimensional (2D) supramolecular architecture. Compound 2 displays an unusual 2D polyrotaxane-like network.

Wang, Jingyuan; Zhang, Yu; Ji, Yanyan

2009-02-01

210

Distortional supramolecular isomers of polyrotaxane coordination polymers: photoreactivity and sensing of nitro compounds.  

PubMed

Distortional isomers, or bond-stretch isomers, differ only in the length of one or more bonds, which is due to crystallographic disorder in most cases. The term distortional isomerism is introduced to describe the structures of polyrotaxane 2D coordination polymers (CPs) that differ only by the relative positions in the neighboring entangled axles. A large ring and a long spacer ligand in 2D CPs yielded four different supramolecular isomers, of which two have an entangled polyrotaxane structure. One pair of C=C bonds in the spacer ligand is well-aligned in one isomer and undergoes [2+2] cycloaddition reaction, whereas the other isomer is photoinert. They also have different sensing efficiency for several aromatic nitro compounds. However, both isomers show selective PL quenching for the Brady's reagent. Structurally similar supramolecular isomers with different photochemical reactivity and sensing abilities appear to be unprecedented. PMID:24729582

Park, In-Hyeok; Medishetty, Raghavender; Kim, Ja-Yeon; Lee, Shim Sung; Vittal, Jagadese J

2014-05-26

211

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

212

Weak cooperativity in selected iron(II) 1D coordination polymers  

NASA Astrophysics Data System (ADS)

The spin crossover behaviour of a new class of FeII coordination polymers [Fe(phtptrz)3]I2 ( 1), [Fe(phtptrz)3](ReO4)2•CH3OH ( 2) and [Fe(phtptrz)3]TaF7•6H2O ( 3) based on a novel ligand 4-(3' -N-phtalimido-propyl)-1,2,4-triazole (phtptrz), were investigated by temperature dependent 57Fe Mössbauer spectroscopy and magnetic susceptibility measurements. The adverse effect of bulky substituent on 1,2,4-triazole, favorable supramolecular interactions and influence of increasing anion size on spin crossover profile is discussed. 1 and 2 show thermally induced spin conversions of gradual and incomplete nature with associated thermochromism, and transition temperatures T1/2 ~ 163 K and 137 K, respectively. A spin state crossover is also identified for 3.

Dîrtu, Marinela M.; Gillard, Damien; Naik, Anil D.; Rotaru, Aurelian; Garcia, Yann

2012-03-01

213

Hydrothermal synthesis and structural characterization of two novel lanthanide supramolecular coordination polymers with nano-chains  

Microsoft Academic Search

Two novel lanthanide supramolecular coordination polymers, {[Nd2(phth)3(phen)(H2O)]·H2O}n (1, phth=phthalate, phen=1,10-phenanthroline) and {[Ho2(phth)3(phen)(H2O)2]·3H2O}n (2), have been synthesized by hydrothermal method and characterized by X-ray diffraction. The results show that complex 1 crystallizes in triclinic space group P1? with a=7.605(2)Å, b=12.972(4)Å, c=18.773(6)Å, ?=109.778(5)°, ?=91.657(5)°, ?=103.951(5)° and Z=2. Complex 1 has a one-dimentional nano-chain structure and the existence of hydrogen bonds and ?–?

Yong-Hong Wan; Lin-Pei Jin; Ke-Zhi Wang

2003-01-01

214

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

215

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

216

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

217

A 3D porous indium(III) coordination polymer involving in-situ ligand synthesis  

SciTech Connect

The hydrothermal reaction of In{sup 3+} and 1,2,4-benzenetricarboxylic acid with the presence of piperazine leads to the generation of a novel 3D porous coordination polymer, [H{sub 3}O][In{sub 2}(btc)(bdc)(OH){sub 2}].5.5H{sub 2}O (1), (btc=1,2,4-benzenetricarboxylate, bdc=1,4-benzenedicarboxylate). Compound 1 crystallizes in orthorhombic space group Pbca with a=16.216(7) A, b=13.437(6) A, c=31.277(14) A, and Z=8. It is interesting to find that the in-situ decarboxylation reaction of 1,2,4-benzenetricarboxylate (btc) partially transformed into 1,4-benzenedicarboxylate (bdc) occurs. The 16 indium(III) centers were linked by four btc, four bdc and two mu{sub 2}-OH ligands to form a box-girder. The adjacent box-girders are further connected by the bdc and btc ligands to generate a novel porous metal-organic framework containing nanotubular open channel with a cross-section of approximately 11.5x11.3 A{sup 2}. The micropores are occupied by lattice water molecules, and the solvent-accessible volume of the unit cell was estimated to be 3658.6 A{sup 3}, which is approximately 53.7% of the unit-cell volume (6815.4 A{sup 3}). - Graphical Abstract: The hydrothermal reaction of In{sup 3+} and 1,2,4-benzenetricarboxylic acid with the presence of piperazine leads to the generation of a novel 3D porous coordination polymer, [H{sub 3}O][In{sub 2}(btc)(bdc)(OH){sub 2}].5.5H{sub 2}O, (btc=1,2,4-benzenetricarboxylate, bdc=1,4-benzenedicarboxylate).

Han Zhengbo, E-mail: ceshzb@lnu.edu.c [College of Chemistry, Liaoning University, Shenyang 110036 (China); Song Yongjuan; Ji Jianwei; Zhang Wei; Han Guangxi [College of Chemistry, Liaoning University, Shenyang 110036 (China)

2009-11-15

218

Carboxyl Group (?CO2 H) Functionalized Coordination Polymer Nanoparticles as Efficient Platforms for Drug Delivery.  

PubMed

Functionalization of nanoparticles can significantly influence their properties and potential applications. Although researchers can now functionalize metal, metal oxide, and organic polymer nanoparticles with a high degree of precision, controlled surface functionalization of nanoscale coordination polymer particles (CPPs) has remained a significant challenge. The lack of methodology is perhaps one of the greatest roadblocks to the advancement of CPPs into high added-value drug delivery applications. Here, we report having achieved this goal through a stepwise formation and functionalization protocol. We fabricated robust nanoparticles with enhanced thermal and colloidal stabilities by incorporation of carboxyl groups and these surface carboxyl groups could be subsequently functionalized through well-known peptide coupling reactions. The set of chemistries that we employed as proof-of-concept enabled a plethora of new functional improvements for the application of CPPs as drug delivery carriers, including enhanced colloidal stabilities and the incorporation of additional functional groups such as polyethylene glycol (PEG) or fluorescent dyes that enabled tracking of their cellular uptake. Finally, we ascertained the cytotoxicity of the new CPP nanoparticles loaded with camptothecin to human breast adenocarcinoma (MCF-7). Efflux measurements show that the encapsulation of camptothecin enhances the potency of the drug 6.5-fold and increases the drug retention within the cell. PMID:25284328

Novio, Fernando; Lorenzo, Julia; Nador, Fabiana; Wnuk, Karolina; Ruiz-Molina, Daniel

2014-11-17

219

Assessing the inherent uncertainty of one-dimensional diffusions  

NASA Astrophysics Data System (ADS)

In this paper we assess the inherent uncertainty of one-dimensional diffusion processes via a stochasticity classification which provides an à la Mandelbrot categorization into five states of uncertainty: infra-mild, mild, borderline, wild, and ultra-wild. Two settings are considered. (i) Stopped diffusions: the diffusion initiates from a high level and is stopped once it first reaches a low level; in this setting we analyze the inherent uncertainty of the diffusion's maximal exceedance above its initial high level. (ii) Stationary diffusions: the diffusion is in dynamical statistical equilibrium; in this setting we analyze the inherent uncertainty of the diffusion's equilibrium level. In both settings general closed-form analytic results are established, and their application is exemplified by stock prices in the stopped-diffusions setting, and by interest rates in the stationary-diffusions setting. These results provide a highly implementable decision-making tool for the classification of uncertainty in the context of one-dimensional diffusions.

Eliazar, Iddo; Cohen, Morrel H.

2013-01-01

220

Coherent transmission through a one-dimensional lattice  

NASA Astrophysics Data System (ADS)

Based on the Keldysh nonequilibrium Green function (NGF) technique, a general formula for the current and transmission coefficient through a one-dimensional lattice is derived without the consideration of electron-electron interactions. We obtain an analytical condition for perfect resonant transmission when the levels of sites are aligned, which depends on the parity of the number of sites. Localization-delocalization transition in a generic one-dimensional disordered lattice is also analyzed, depending on the correlation among the hopping parameters and the strength of the coupling to reservoirs. The dependence of the number and lineshape of resonant transmission and linear conductance peaks on the structure parameters of the lattice is also given in several site cases.

Zeng, Zhao Yang; Nie, Yi-You; Claro, F.; Yan, W.

2004-10-01

221

Clustering in a one-dimensional inelastic lattice gas  

NASA Astrophysics Data System (ADS)

We analyze a lattice model closely related to the one-dimensional inelastic gas with periodic boundary condition. The one-dimensional inelastic gas tends to form high density clusters of particles with almost the same velocity, separated by regions of low density; plotted as a function of particle indices, the velocities of the gas particles exhibit sharp gradients, which we call shocks. Shocks and clusters are seen to form in the lattice model too, although no true positions of the particles are taken into account. The locations of the shocks in terms of the particle index show remarkable independence on the coefficient of restitution and the sequence of collisions used to update the system, but they do depend on the initial configuration of the particle velocities. We explain the microscopic origin of the shocks. We show that dynamics of the velocity profile inside a cluster satisfies a simple continuum equation, thereby allowing us to study cluster-cluster interactions at late times.

Ostojic, Srdjan; Panja, Debabrata; Nienhuis, Bernard

2004-04-01

222

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

223

Experimental system for one-dimensional rotational brownian motion.  

PubMed

We present here an experimental, strictly one-dimensional rotational system, made by using single magnetic Janus particles in a static magnetic field. These particles were half-coated with a thin metallic film, and by turning on a properly oriented external static magnetic field, we monitor the rotational brownian motion of single particles, in solution, around the desired axis. Bright-field microscopy imaging provides information on the particle orientation as a function of time. Rotational diffusion coefficients are derived for one-dimensional rotational diffusion, both for a single rotating particle and for a cluster of four such particles. Over the studied time domain, up to 10 s, the variation of the angle of rotation is strictly brownian; its probability distribution function is gaussian, and the mean squared angular displacement is linear in time, as expected for free diffusion. Values for the rotational diffusion coefficients were also determined. Monte Carlo and hydrodynamic simulations agree well with the experimental results. PMID:21500841

McNaughton, Brandon H; Kinnunen, Paivo; Shlomi, Miri; Cionca, Codrin; Pei, Shao Ning; Clarke, Roy; Argyrakis, Panos; Kopelman, Raoul

2011-05-12

224

One-dimensional Hubbard-Luttinger model for carbon nanotubes  

E-print Network

A Hubbard-Luttinger model is developed for qualitative description of one-dimensional motion of interacting Pi-conductivity-electrons in carbon single-wall nanotubes at low temperatures. The low-lying excitations in one-dimensional electron gas are described in terms of interacting bosons. The Bogolyubov transformation allows one to describe the system as an ensemble of non-interacting quasi-bosons. Operators of Fermi-excitations and Green functions of fermions are introduced. The electric current is derived as a function of potential difference on the contact between a nanotube and a normal metal. Deviations from Ohm law produced by electron-electron short-range repulsion as well as by the transverse quantization in single-wall nanotubes are discussed. The results are compared with experimental data.

Ishkhanyan, H A

2014-01-01

225

The First Noncluster Vanadium(IV) Coordination Polymers: Solvothermal Syntheses, Crystal Structure, and Ion Exchange  

NASA Astrophysics Data System (ADS)

Two isostructural vanadium(IV) coordination polymers [VO(dod) 2] X2 [ X=Cl, Br; dod=1,4-diazoniabicyclo[2,2,2] octane-1,4-diacetate (C 10H 16N 2O 4)] have been synthesized solvothermally and determined by single-crystal X-ray analysis. Both of them crystallize in the tetragonal space group P4/ ncc (no. 130), with cell parameters a=15.702(5), c=9.745(5) Å, V=2403(2) Å 3, Z=4 for 1 and a=15.916(5), c=9.820(4) Å, V=2488(2) Å 3, Z=4 for 2. In both complexes, each vanadium atom adopts a V IVO 5 square-pyramidal environment, being coordinated by four oxygen atoms [V-O=1.978(2) Å for 1 and 1.969(3) Å for 2] from four dod ligands and a terminal oxygen atom [V=O=1.580(5) Å for 1 and 1.572(7) Å for 2]. The bis-monodentate dod ligands bridge vanadium atoms to furnish two-dimensional double wave-like layers of (4,4) topological type. Along the c-axis direction, there are square channels constructed from side-sharing saddle-shaped rings. The microporous material 1 shows chloride-to-sulfate exchange properties in aqueous media.

Zhang, Xian-Ming; Tong, Ming-Liang; Lee, Hung Kay; Chen, Xiao-Ming

2001-08-01

226

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

227

Cavity modes in one-dimensional photonic crystal slabs  

Microsoft Academic Search

A theoretical study of cavity modes in one-dimensional photonic crystal slabs embedded in Silicon-on-Insulator structures is reported. Three different methods are employed, namely a guided-mode expansion in which the coupling to radiative modes is treated by perturbation theory, a grating or scattering-matrix method for calculating the surface reflectance, and a Fourier modal expansion for in-plane transmission calculations. It is shown

D. Gerace; M. Agio; L. C. Andreani; P. Lalanne

2005-01-01

228

Image processing using one-dimensional processor arrays  

Microsoft Academic Search

The first half of this paper presents the design rationale for CNAPS, a specialized one-dimensional (1-D) processor array developed by Adaptive Solutions Inc. In this context, we discuss the problem of Amdahl's law which severely constrains special-purpose architectures. We also discuss specific architectural decisions such as the kind of parallelism, the computational precision of the processors, on-chip versus off-chip processor

DAN W. HAMMERSTROM; DANIEL P. LULICH

1996-01-01

229

Cloud pumping in a one-dimensional photochemical model  

NASA Technical Reports Server (NTRS)

Cloud pumping data based on tropical maritime updraft statistics are incorporated in a one-dimensional steady-state eddy diffusive photochemical model of the troposphere. It is suggested that regions with weaker convection, such as the midlatitudes, may also experience substantial effects from cloud pumping. The direct effects of cloud pumping on CO were found to be more significant than implied by sensitivity studies. The (CH3)2S profile computed with cloud pumping agrees well with previous data.

Costen, Robert C.; Tennille, Geoffrey M.; Levine, Joel S.

1988-01-01

230

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

231

One-dimensional model of vapor-dominated geothermal systems  

Microsoft Academic Search

A one-dimensional model of vapor-dominated geothermal systems in the natural state is developed in order to study the ranges of the heat and mass transport and flow resistance at which a system is capable of existing in the vapor-dominated state. The model consists of a near-surface condensate layer lying above a two-phase counterflow region with rising steam and descending water

J. M. Straus; Gerald Schubert

1981-01-01

232

Electrochromic properties of one-dimensional tungsten oxide nanobundles  

Microsoft Academic Search

In this study, one-dimensional (1D) tungsten oxide nanobundles (TNB) were synthesized via a simple solvothermal method. The phase of 1D tungsten oxide was W18O49, and the diameter and length of the building units (nanowires) were about 7 and 800nm, respectively. TNB films were fabricated by the Langmuir–Blodgett (LB) method. The locally arranged domains of the long nanobundles form the LB

Sung Jong Yoo; Young Hwa Jung; Ju Wan Lim; Hong Goo Choi; Do Kyung Kim; Yung-Eun Sung

2008-01-01

233

Hydrogen peroxide stabilization in one-dimensional flow columns  

Microsoft Academic Search

Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H2O2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the

Jeremy T. Schmidt; Mushtaque Ahmad; Amy L. Teel; Richard J. Watts

2011-01-01

234

Hydrogen peroxide stabilization in one-dimensional flow columns  

Microsoft Academic Search

Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H2O2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25mM citrate or phytate was applied to the columns

Jeremy T. Schmidt; Mushtaque Ahmad; Amy L. Teel; Richard J. Watts

235

Quasi-one-dimensional magnons in an intermetallic marcasite  

SciTech Connect

We present inelastic neutron scattering measurements and rst principles calculations examining the intermetallic marcasite CrSb2. The observed spin wave dispersion implies that the magnetic interactions are strongly one-dimensional with antiferromagnetic chains parallel to the crystalline c-axis. Such low-dimensional excitations are unexpected in a semiconducting intermetallic system. Moreover this material may be further interesting in that the magnetic anisotropy may enhance thermoelectric properties along particular crystallographic directions.

Stone, Matthew B [ORNL; Lumsden, Mark D [ORNL; Nagler, Stephen E [ORNL; Singh, David J [ORNL; Sales, Brian C [ORNL; Mandrus, David [ORNL

2012-01-01

236

One-dimensional toy model of globular clusters  

Microsoft Academic Search

We introduce a one-dimensional toy model of globular clusters. The model is a version of the well-known gravitational sheets system, where we also take into account mass and energy loss by evaporation of stars at the boundaries. Numerical integration by the ``exact'' event-driven dynamics is performed, for initial uniform density and Gaussian random velocities. Two distinct quasistationary asymptotic regimes are

Duccio Fanelli; Marco Merafina; Stefano Ruffo

2001-01-01

237

Diffraction images of truncated, one-dimensional, periodic targets.  

PubMed

Formulas are developed that permit the calculation of the diffraction images of truncated, one-dimensional, periodic objects in the presence of incoherent illumination using transfer function theory. Special attention is paid to the important problem of determining the minimum number of cycles that such a target must possess in order for it to act effectively as an infinite periodic target. Illustrative calculations are carried out for aberration-free, defocused systems. PMID:20057792

Barakat, R; Lerman, S

1967-03-01

238

Correlation functions of one-dimensional bosons at low temperature  

E-print Network

We consider the low-temperature limit of the long-distance asymptotic behavior of the finite temperature density-density correlation function in the one-dimensional Bose gas derived recently in the algebraic Bethe ansatz framework. Our results confirm the predictions based on the Luttinger liquid and conformal field theory approaches. We also demonstrate that the amplitudes arising in this asymptotic expansion at low-temperature coincide with the amplitudes associated with the so-called critical form factors.

K. K. Kozlowski; J. M. Maillet; N. A. Slavnov

2011-02-09

239

Fast Integration of One-Dimensional Boundary Value Problems  

NASA Astrophysics Data System (ADS)

Two-point nonlinear boundary value problems (BVPs) in both unbounded and bounded domains are solved in this paper using fast numerical antiderivatives and derivatives of functions of L2(-?, ?). This differintegral scheme uses a new algorithm to compute the Fourier transform. As examples we solve a fourth-order two-point boundary value problem (BVP) and compute the shape of the soliton solutions of a one-dimensional generalized Korteweg-de Vries (KdV) equation.

Campos, Rafael G.; Ruiz, Rafael García

2013-11-01

240

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

241

Quantum Hall effect in a one-dimensional dynamical system  

SciTech Connect

We construct a periodically time-dependent Hamiltonian with a phase transition in the quantum Hall universality class. One spatial dimension can be eliminated by introducing a second incommensurate driving frequency, so that we can study the quantum Hall effect in a one-dimensional (1D) system. This reduction to 1D is very efficient computationally and would make it possible to perform experiments on the 2D quantum Hall effect using cold atoms in a 1D optical lattice.

Dahlhaus, J. P.; Edge, J. M.; Beenakker, C. W. J. [Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, NL-2300 RA Leiden (Netherlands); Tworzydlo, J. [Institute of Theoretical Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland)

2011-09-15

242

A (one-dimensional) free Brunn–Minkowski inequality  

Microsoft Academic Search

We present a one-dimensional version of the functional form of the geometric Brunn–Minkowski inequality in free (non-commutative) probability theory. The proof relies on matrix approximation as used recently by Biane and Hiai et al. to establish free analogues of the logarithmic Sobolev and transportation cost inequalities for strictly convex potentials, that are recovered here from the Brunn–Minkowski inequality as in

Michel Ledoux

2005-01-01

243

On One-Dimensional Propagation of Long Waves  

Microsoft Academic Search

The one-dimensional Schrodinger wave equation for particles of mass m and energy E, psi''+2mhslash-2(E-V) psi = 0 (-? < x < ?). is solved for fairly general potential function V(x) by successive approximations for small de Broglie wave numbers. The method of solution is to use power series in the wave number after the essential singularities at infinity have been

P. G. Drazin

1963-01-01

244

Inversion of one-dimensional scattering data using Prony's method  

SciTech Connect

A one-dimensional configuration is the simplest geometry to invert, yet it has practical application to such problems as scattering from inhomogeneous half spaces and propagation on nonuniform transmision lines. Whether the medium parameters vary continuously or discretely with position, the problem's numerical description can usually be developed in finite-difference approximation. As such, the scattered and transmitted fields can be represented as exponential series, whose exponents are related to the electrical thicknesses of the layers which make up the model. If the exponents or poles are derivable from field data, then the inverse problem is formally solvable. This paper considers application of Prony's method, a procedure for obtaining the poles of exponential signals, to such one-dimensional problems. Analysis of both time-domain and frequency-domain data is studied. The effects of the medium characteristics, number of layers, and other factors are examined. It is concluded that Prony's method has merit for certain classes of one-dimensional inverse problems.

Miller, E.K.; Lager, D.L.

1982-01-01

245

Cryptography using multiple one-dimensional chaotic maps  

NASA Astrophysics Data System (ADS)

Recently, Pareek et al. [Phys. Lett. A 309 (2003) 75] have developed a symmetric key block cipher algorithm using a one-dimensional chaotic map. In this paper, we propose a symmetric key block cipher algorithm in which multiple one-dimensional chaotic maps are used instead of a one-dimensional chaotic map. However, we also use an external secret key of variable length (maximum 128-bits) as used by Pareek et al. In the present cryptosystem, plaintext is divided into groups of variable length (i.e. number of blocks in each group is different) and these are encrypted sequentially by using randomly chosen chaotic map from a set of chaotic maps. For block-by-block encryption of variable length group, number of iterations and initial condition for the chaotic maps depend on the randomly chosen session key and encryption of previous block of plaintext, respectively. The whole process of encryption/decryption is governed by two dynamic tables, which are updated time to time during the encryption/decryption process. Simulation results show that the proposed cryptosystem requires less time to encrypt the plaintext as compared to the existing chaotic cryptosystems and further produces the ciphertext having flat distribution of same size as the plaintext.

Pareek, N. K.; Patidar, Vinod; Sud, K. K.

2005-10-01

246

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

247

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

248

A ratiometric and colorimetric luminescent thermometer over a wide temperature range based on a lanthanide coordination polymer.  

PubMed

A lanthanide coordination polymer Tb0.957Eu0.043cpda was synthesized as a ratiometric and colorimetric luminescent thermometer. The high triplet excited state energy of a linker enables Tb0.957Eu0.043cpda to detect and visualize temperature over a wide range from cryogenic to room temperature (40-300 K). PMID:24287968

Cui, Yuanjing; Zou, Wenfeng; Song, Ruijing; Yu, Jiancan; Zhang, Wenqian; Yang, Yu; Qian, Guodong

2014-01-21

249

Monocrystalline mesoporous metal oxide with perovskite structure: a facile solid-state transformation of a coordination polymer.  

PubMed

Monocrystalline mesoporous BiFeO3 crystals were obtained via a multi-step single-crystal to single-crystal transformation of a coordination polymer, Bi[Fe(CN)6]·4H2O. This unique transformation process significantly decreased the crystallization temperature of perovskite oxide without losing high crystallinity. PMID:25259374

Xu, Li; Bu, Fan-Xing; Hu, Ming; Jin, Chuan-Yin; Jiang, Dong-Mei; Zhao, Zhen-Jie; Zhang, Qing-Hong; Jiang, Ji-Sen

2014-10-14

250

A unique three-dimensional coordination polymer constructed from 4,4 ?-biphenyldicarboxylate and zinc(II)  

Microsoft Academic Search

Zinc(II) coordination polymer [Zn(bpdc)]n (bpdc=4,4?-biphenyldicarboxylate) (1) with a unique entanglement PtS structure was synthesized by hydrothermal reaction of zinc nitrate and 4,4-biphenyldicarboxylic acid in aqueous sodium hydroxide solution.

La-Sheng Long; Yan-Ping Ren; Li-Hua Ma; Yun-Bao Jiang; Rong-Bin Huang; Lan-Sun Zheng

2003-01-01

251

Ion conductivity and transport by porous coordination polymers and metal-organic frameworks.  

PubMed

Ion conduction and transport in solids are both interesting and useful and are found in widely distinct materials, from those in battery-related technologies to those in biological systems. Scientists have approached the synthesis of ion-conductive compounds in a variety of ways, in the areas of organic and inorganic chemistry. Recently, based on their ion-conducting behavior, porous coordination polymers (PCPs) and metal-organic frameworks (MOFs) have been recognized for their easy design and the dynamic behavior of the ionic components in the structures. These PCP/MOFs consist of metal ions (or clusters) and organic ligands structured via coordination bonds. They could have highly concentrated mobile ions with dynamic behavior, and their characteristics have inspired the design of a new class of ion conductors and transporters. In this Account, we describe the state-of-the-art of studies of ion conductivity by PCP/MOFs and nonporous coordination polymers (CPs) and offer future perspectives. PCP/MOF structures tend to have high hydrophilicity and guest-accessible voids, and scientists have reported many water-mediated proton (H(+)) conductivities. Chemical modification of organic ligands can change the hydrated H(+) conductivity over a wide range. On the other hand, the designable structures also permit water-free (anhydrous) H(+) conductivity. The incorporation of protic guests such as imidazole and 1,2,4-triazole into the microchannels of PCP/MOFs promotes the dynamic motion of guest molecules, resulting in high H(+) conduction without water. Not only the host-guest systems, but the embedding of protic organic groups on CPs also results in inherent H(+) conductivity. We have observed high H(+) conductivities under anhydrous conditions and in the intermediate temperature region of organic and inorganic conductors. The keys to successful construction are highly mobile ionic species and appropriate intervals of ion-hopping sites in the structures. Lithium (Li(+)) and other ions can also be transported. If we can optimize the crystal structures, this could offer further improvements in terms of both conductivity and the working temperature range. Another useful characteristic of PCP/MOFs is their wide application to materials fabrication. We can easily prepare heterodomain crystal systems, such as core-shell or solid solution. Other anisotropic morphologies (thin film, nanocrystal, nanorod, etc.,) are also possible, with retention of the ion conductivity. The flexible nature also lets us design morphology-dependent ion-conduction behaviors that we cannot observe in the bulk state. We propose (1) multivalent ion and anion conductions with the aid of redox activity and defects in structures, (2) control of ion transport behavior by applying external stimuli, (3) anomalous conductivity at the hetero-solid-solid interface, and (4) unidirectional ion transport as in the ion channels in membrane proteins. In the future, scientists may use coordination polymers not only to achieve higher conductivity but also to control ion behavior, which will open new avenues in solid-state ionics. PMID:23730917

Horike, Satoshi; Umeyama, Daiki; Kitagawa, Susumu

2013-11-19

252

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

253

How to Define Variation of Physical Properties Normal to an Undulating One-Dimensional Object  

E-print Network

One-dimensional flexible objects are abundant in physics, from polymers to vortex lines to defect lines and many more. These objects structure their environment and it is natural to assume that the influence these objects exert on their environment depends on the distance from the line-object. But how should this be defined? We argue here that there is an intrinsic length scale along the undulating line that is a measure of its "stiffness" (i.e., orientational persistence), which yields a natural way of defining the variation of physical properties normal to the undulating line. We exemplify how this normal variation can be determined from a computer simulation for the case of a so-called bottle-brush polymer, where side chains are grafted onto a flexible backbone.

Hsiao-Ping Hsu; Kurt Binder; Wolfgang Paul

2009-11-15

254

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

255

Superconducting cosmic strings and one dimensional extended supersymmetric algebras  

NASA Astrophysics Data System (ADS)

In this article we study in detail the supersymmetric structures that underlie the system of fermionic zero modes around a superconducting cosmic string. Particularly, we extend the analysis existing in the literature on the one dimensional N=2 supersymmetry and we find multiple N=2, d=1 supersymmetries. In addition, compact perturbations of the Witten index of the system are performed and we find to which physical situations these perturbations correspond. More importantly, we demonstrate that there exists a much more rich supersymmetric structure underlying the system of fermions with Nf flavors and these are N-extended supersymmetric structures with non-trivial topological charges, with “N” depending on the fermion flavors.

Oikonomou, V. K.

2014-11-01

256

Explicit phase diagram for a one-dimensional blister model  

E-print Network

In this article, we consider a simple one-dimensional variational model, describing the delamination of thin films under cooling. We characterize the global minimizers, which correspond to films of three possible types: non delaminated, partially delaminated (called blisters), or fully delaminated. Two parameters play an important role: the length of the film and the cooling parameter. In the phase plane of those two parameters, we classify all the minimizers. As a consequence of our analysis, we identify explicitly the smallest possible blisters for this model.

Ghada Chmaycem; Mustapha Jazar; Régis Monneau

2014-02-16

257

One-dimensional photonic crystals with cylindrical geometry.  

PubMed

A one-dimensional photonic crystal (1DPC) consisting of a stack of alternate TiO2 and Al2O3 layers is deposited on the side wall of a glass rod by Atomic Layer Deposition. The stack is designed to sustain TE-polarized Bloch Surface Waves (BSW) in the visible spectrum at wavelengths shorter than 650 nm. Experimental evidence of light coupling and guiding capabilities of the 1DPC is provided together with a possible application for fluorescence-based remote sensors. PMID:25401874

Roussey, Matthieu; Descrovi, Emiliano; Häyrinen, Markus; Angelini, Angelo; Kuittinen, Markku; Honkanen, Seppo

2014-11-01

258

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

259

Spin Waves in a One-Dimensional Spinor Bose Gas  

SciTech Connect

We study a one-dimensional (iso)spin 1/2 Bose gas with repulsive {delta}-function interaction by the Bethe Ansatz method and discuss the excitations above the polarized ground state. In addition to phonons the system features spin waves with a quadratic dispersion. We compute analytically and numerically the effective mass of the spin wave and show that the spin transport is greatly suppressed in the strong coupling regime, where the isospin-density (or 'spin-charge') separation is maximal. Using a hydrodynamic approach, we study spin excitations in a harmonically trapped system and discuss prospects for future studies of two-component ultracold atomic gases.

Fuchs, J.N. [Laboratoire de Physique des Solides, Universite Paris-Sud, ba circumflex t. 510, F-91405 Orsay (France); Gangardt, D.M. [Laboratoire de Physique Theorique et Modeles Statistiques, Universite Paris-Sud, bat. 100, F-91405 Orsay (France); Keilmann, T. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann Str. 1, D-85748 Garching (Germany); Shlyapnikov, G.V. [Laboratoire de Physique Theorique et Modeles Statistiques, Universite Paris-Sud, bat. 100, F-91405 Orsay (France); Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65/67, 1018 XE Amsterdam (Netherlands)

2005-10-07

260

On Global One-Dimensionality proposal in Quantum General Relativity  

E-print Network

Quantum General Relativity, better known as Quantum Gravity with additional epithets, currently is faraway from phenomenology. This mental crisis leads at most to empty hypotheses, but not to realistic physics. However, there exists the way, investigated by Dirac, which is constructive for experimental data predictions in astrophysics, high energy physics, and condensed matter physics. It is Field Theory. This article presents certain proposal for new discussion. General Relativity in 3+1 metric field gauge and its canonical quantization is developed. Reduction of the quantum geometrodynamics to Global One-Dimensional bosonic field theory, its quantization, and some conclusions are presented.

Glinka, L A

2008-01-01

261

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

262

One dimensional Brownian motion in hard rods: adiabatic piston problem  

E-print Network

We have investigated the motion characteristics of a movable piston immersed in a one dimensional gas of hard rods by event-oriented molecular dynamics in the absence of thermal noise. Periodic and reflecting boundary conditions are explored. It is shown that the piston undergoes systematic oscillations with decaying amplitudes in short times before it comes to global thermodynamic equilibrium. Moreover, the diffusion of the piston is explored and analytical expressions for its equilibrium mean-squared displacement is obtained. It is shown that MSD of the piston does not differ much from the normal rods despite its mass and length are significantly larger.

M. Ebrahim Foulaadvand; M. Mehdi Shafiee

2014-09-11

263

One-dimensional nanostructures based bio-detection.  

PubMed

This paper presents a review on recent developments of one-dimensional (1-D) nanostructures based label-free chemiresistive/chemFET biosensors and the various sensing mechanisms used for biomolecular detection. The sensor performance including sensitivity, selectivity, and reliability is compared in terms of material synthesis of the sensor's element, relating surface functionalization schemes to their properties with respect to selected bioreceptors, its method of fabrication, and its intended operation. As a final point, we outline the prospects of chemiresistive/chemFET biosensors and recommend specific advancements in this field. PMID:25128623

Chartuprayoon, Nicha; Zhang, Miluo; Bosze, Wayne; Choa, Yong-Ho; Myung, Nosang V

2015-01-15

264

One dimensional s-wave holographic superconductor with supercurrent  

E-print Network

We study the one dimensional s-wave holographic superconductor by turning on the vector potential $A_x$ in the bulk, which behaves as $A_x=A_x^{(0)} \\ln z+ A_x^{(1)}$ on the boundary. By solving the model with fixed $A_x^{(0)}$, we find that if we identify the $A_x^{(0)}$ with the supercurrent $j_x$ of the holographic superconductor, the results agree with the Gindzburg- Landau theory. For example, $A_x^{(0)}$ will break the superconductivity, and the critical value of $A_x^{(0)}$ is proportional to $(T_c-T)^{3/2}$.

Hua-Bi Zeng

2012-04-24

265

Quantum mechanics of graphene with a one-dimensional potential  

SciTech Connect

Electron states in graphene with a one-dimensional potential have been studied. An approximate solution has been obtained for a small angle between vectors of the incident electron momentum and potential gradient. Exactly solvable problems with a potential of the smoothened step type U(x) Utanh(x/a) and a potential with a singularity U(x) = -U/(|x| + d) are considered. The transmission/reflection coefficients and phases for various potential barriers are determined. A quasi-classical solution is obtained.

Miserev, D. S. [Novosibirsk State University (Russian Federation); Entin, M. V., E-mail: entin@isp.nsc.ru [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2012-10-15

266

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

267

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

268

Propagation of nonclassical correlations through one-dimensional quantum networks  

NASA Astrophysics Data System (ADS)

We investigate transfer of nonclassical correlations through one-dimensional quantum networks for several schemes by employing concurrence and local quantum uncertainty as the measures and the extended Werner-like states as the initial resources. The exact dynamics of quantum correlations are derived, and the differences of dynamics between concurrence and local quantum uncertainty are analyzed. Besides, the influences of node number and initial parameters on the generation of quantum correlations between the two end nodes are discussed. Moreover, we explore the effects of duplex encodings and double channels on distribution of quantum correlations.

Hu, Zheng-Da; Zhang, Yixin; Zhang, Ye-Qi

2014-08-01

269

A series of Zn-4f heterometallic coordination polymers and a zinc complex containing a flexible mixed donor dicarboxylate ligand.  

PubMed

A new zinc compound, together with a corresponding series of Zn-4f heterometallic coordination polymers, namely, [Zn(H2PBDA)(PBDA)]n (1), {[Ln2(PBDA)2·2H2O] [Zn2(PBDA)2Cl2]}n [H2PBDA = 3-(pyridin-3-yl-oxy) benzene-1,2-dicarboxylic acid, and Ln = Pr(2), Nd(3), Eu(4), Gd(5), Dy(6), Ho(7), Er(8)] have been hydrothermally synthesized and characterized systematically. Polymers 2-8 feature two-dimensional (2D) 4,4 networks, containing the original 1D heterometallic double stranded chains composed of [Ln2Zn2(PBDA)2] entities. The extensive hydrogen bonding and ?-? stacking interactions were observed to stabilize the extended architectures. The luminescence emission spectra of the polymers vary depending on the lanthanide(III) ion present. Informative magnetic susceptibility measurements show that the same carboxylate bridging fashion of the PBDA ligand results in the different magnetic properties occurring within the heterometallic coordination polymers. In addition, polymer 6 exhibits an interesting slow magnetic relaxation behavior at lower temperatures. PMID:23549773

Feng, Xun; Feng, Yu-Quan; Liu, Lang; Wang, Li-Ya; Song, Hong-Liang; Ng, Seik-Weng

2013-06-01

270

N-(sulfoethyl) iminodiacetic acid-based lanthanide coordination polymers: Synthesis, magnetism and quantum Monte Carlo studies  

SciTech Connect

A series of lanthanide coordination polymers have been obtained through the hydrothermal reaction of N-(sulfoethyl) iminodiacetic acid (H{sub 3}SIDA) and Ln(NO{sub 3}){sub 3} (Ln=La, 1; Pr, 2; Nd, 3; Gd, 4). Crystal structure analysis exhibits that lanthanide ions affect the coordination number, bond length and dimension of compounds 1-4, which reveal that their structure diversity can be attributed to the effect of lanthanide contraction. Furthermore, the combination of magnetic measure with quantum Monte Carlo(QMC) studies exhibits that the coupling parameters between two adjacent Gd{sup 3+} ions for anti-anti and syn-anti carboxylate bridges are -1.0 Multiplication-Sign 10{sup -3} and -5.0 Multiplication-Sign 10{sup -3} cm{sup -1}, respectively, which reveals weak antiferromagnetic interaction in 4. - Graphical abstract: Four lanthanide coordination polymers with N-(sulfoethyl) iminodiacetic acid were obtained under hydrothermal condition and reveal the weak antiferromagnetic coupling between two Gd{sup 3+} ions by Quantum Monte Carlo studies. Highlights: Black-Right-Pointing-Pointer Four lanthanide coordination polymers of H{sub 3}SIDA ligand were obtained. Black-Right-Pointing-Pointer Lanthanide ions play an important role in their structural diversity. Black-Right-Pointing-Pointer Magnetic measure exhibits that compound 4 features antiferromagnetic property. Black-Right-Pointing-Pointer Quantum Monte Carlo studies reveal the coupling parameters of two Gd{sup 3+} ions.

Zhuang Guilin, E-mail: glzhuang@zjut.edu.cn [Institute of Industrial Catalysis, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Chen Wulin [Institute of Industrial Catalysis, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Zheng Jun [Center of Modern Experimental Technology, Anhui University, Hefei 230039 (China); Yu Huiyou [Institute of Industrial Catalysis, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Wang Jianguo, E-mail: jgw@zjut.edu.cn [Institute of Industrial Catalysis, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

2012-08-15

271

One-dimensional M.Gromov's problem on minimal filling  

E-print Network

The present paper opens a new branch in the theory of variational problems with branching extremals, the investigation of one-dimensional minimal fillings of finite pseudo-metric spaces. On the one hand, this problem is a one-dimensional version of a generalization of M. Gromov minimal fillings problem to the case of stratified manifolds (the filling in our case is a weighted graph). On the other hand, this problem is interesting itself and also can be considered as a generalization of another classical problem, namely, Steiner problem on the construction of a shortest network joining a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings, describe minimal fillings of additive spaces, and state several conjectures. We also include some announcements concerning the very recent results obtained in our group, including a formula calculating the weight of the minimal filling for an arbitrary finite pseudo-metric space and the concept of pseudo-additiv...

Ivanov, A O

2011-01-01

272

Constraint and gauge shocks in one-dimensional numerical relativity  

NASA Astrophysics Data System (ADS)

We study how different types of blowups 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 blowups can be expected. One criteria is related to the so-called geometric blowup leading to gradient catastrophes, while the other is based upon the ODE-mechanism leading to blowups 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 blowups can appear in one-dimensional numerical relativity. In the latter case we recover the well known “gauge shocks” associated with Bona-Massó type slicing conditions. However, a crucial result of this study has been the identification of a second family of blowups associated with the way in which the constraints have been used to construct a hyperbolic formulation. We call these blowups “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.

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

2005-03-01

273

Generating arbitrary one-dimensional dose profiles using rotational therapy  

NASA Astrophysics Data System (ADS)

Conformal radiation therapy can be delivered using several methods: intensity-modulated radiotherapy (IMRT) at fixed gantry angles, through the continuous gantry rotation of linac (rotational arc therapy), or by a dedicated treatment unit such as tomotherapy. The recently developed volumetric modulated arc therapy (VMAT), a form of rotational arc therapy, has attracted lots of attention from investigators to explore its capability of generating highly conformal dose to the target. The main advanced features of VMAT are the variable dose rate and gantry rotation speed. In this paper, we present a theoretical framework of generating arbitrary one-dimensional dose profiles using rotational arc therapy to further explore the new degree of freedom of the VMAT technique. This framework was applied to design a novel technique for total body irradiation (TBI) treatment, where the desired dose distribution can be simplified by a one-dimensional profile. The technique was validated using simulations and experimental measurements. The preliminary results demonstrated that the new TBI technique using either dynamic MLC only, variable dose rate only, or a combination of dynamic MLC and variable dose rate can achieve arbitrary dose distribution in one dimension, such as uniform dose to target and lower dose to critical organ. This technique does not require the use of customized compensators, nor large treatment rooms as in the conventional extended SSD technique.

Zhuang, Tingliang; Wu, Qiuwen

2010-10-01

274

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

275

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

276

Solvothermal synthesis of four polyoxometalate-based coordination polymers including diverse Ag(I)···? interactions.  

PubMed

Four 3D POM-based silver coordination polymers, namely, [Ag17(ptz)11(PW12O40)2]n (1), [Ag17(ptz)11(PMo12O40)2]n (2), [Ag12(ptz)6(CN)2(SiW12O40)]n (3), and [Ag19(ptz)8(H2ptz)(H3ptz)(AgP5W30O110)·7H2O]n (4), have been obtained by solvothermal reaction of AgNO3 and 5-phenyl-1H-tetrazole (Hptz) ligand in the presence of four types of polyoxometalates. Structural analysis shows that four types of Ag(I)···? interactions, m-?(1), m/p-?(2), o/m-?(2), and o/m/p-?(3), were observed in compounds 1-4, depending on the polyoxometalates used. The in situ generated CN(-) ion in compound 3 shows unprecedented mixed ? and ? bonding modes, similar to the C2(2-) ion in well-studied silver acetylides. For 4, the Na(+) ion in the Preyssler heteropolyoxoanion, [NaP5W30O110](14-), was exchanged by Ag(I) under solvothermal conditions, generating a novel [AgP5W30O110](14-) anion. In addition, the photoluminescence behavior of 1-4 was also investigated. PMID:24392969

Liang, Min-Xia; Ruan, Chan-Zi; Sun, Di; Kong, Xiang-Jian; Ren, Yan-Ping; Long, La-Sheng; Huang, Rong-Bin; Zheng, Lan-Sun

2014-01-21

277

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

278

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

279

A family of 2D and 3D coordination polymers involving a trigonal tritopic linker.  

PubMed

Five new coordination polymers, namely, [Zn(2)(H(2)O)(2)(BBC)](NO(3))(DEF)(6) (DUT-40), [Zn(3)(H(2)O)(3)(BBC)(2)] (DUT-41), [(C(2)H(5))(2)NH(2)][Zn(2)(BBC)(TDC)](DEF)(6)(H(2)O)(7) (DUT-42), [Zn(10)(BBC)(5)(BPDC)(2)(H(2)O)(10)](NO(3))(DEF)(28)(H(2)O)(8) (DUT-43), and [Co(2)(BBC)(NO(3))(DEF)(2)(H(2)O)](DEF)(6)(H(2)O) (DUT-44), where BBC--4,4',4''-(benzene-1,3,5-triyl-tris(benzene-4,1-diyl))tribenzoate, TDC--2,5-thiophenedicarboxylate, BPDC--4,4'-biphenyldicarboxylate, DEF--,N-diethylformamide, were obtained under solvothermal conditions and structurally characterized. It has been shown that compounds DUT-40, DUT-41 and DUT-44 exhibit 2D layered structures with large hexagonal channels. Utilization of additional angular dicarboxylic TDC linker led to the formation of the DUT-42 compound with the structure consisting of three interpenetrated 3D networks. Using the linear co-linker dicarboxylic BPDC, DUT-43 was obtained which forms a complicated 3D architecture arising from the polycatenation of triple-layered 2D building units and 2D single layer units. The pore accessibility of the synthesized compounds in the liquid phase was proved by the adsorption of dye molecules. PMID:22293901

Hauptvogel, Ines Maria; Bon, Volodymyr; Grünker, Ronny; Baburin, Igor A; Senkovska, Irena; Mueller, Uwe; Kaskel, Stefan

2012-04-14

280

Preparation of nanocrystalline metal oxides and intermetallic phases by controlled thermolysis of organometallic coordination polymers  

NASA Astrophysics Data System (ADS)

Organometallic coordination polymers of the super-Prussian blue type [(Me 3Sn) nM(CN) 6] (Me=CH 3; n=3, 4; M=Fe, Co, Ru) were subjected to thermolysis in different atmospheres (air, argon, hydrogen/nitrogen). In air, oxides were found: Fe 2O 3/SnO 2 (crystalline and nanocrystalline), Co 2SnO 4 and RuO 2. In argon and in hydrogen, the intermetallic phases FeSn 2, CoSn 2, Ru 3Sn 7 and Fe 3SnC were obtained. A detailed mechanistic study was carried out using thermogravimetry (TG), X-ray diffraction (XRD), X-ray absorption spectroscopy (EXAFS) at Fe, Co, Ru and Sn K-edges, infrared spectroscopy (IR) and elemental analysis. Below 250°C, Me 3SnCN and (CN) 2 are released, whereas above 250°C oxidation or pyrolysis leads to the corresponding oxides or intermetallic phases. Polymeric cyanides containing at least two metals have turned out to be suitable precursors to prepare well-defined oxides and intermetallic phases at comparatively low temperature.

Rehbein, Marcus; Epple, Matthias; Fischer, R. Dieter

2000-06-01

281

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

PubMed

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. PMID:25124847

Etaiw, Safaa El-Din H; Abdou, Safaa N

2015-01-25

282

Two coordination polymers of manganese(II) isophthalate and their preparation, structures, and magnetic properties  

SciTech Connect

Two manganese coordination polymers, [Mn{sub 2}(ip){sub 2}(dmf)]{center_dot}dmf (1) and [Mn{sub 4}(ip){sub 4}(dmf){sub 6}]{center_dot}2dmf (2) (ip=isophthalate; dmf=N,N-dimethylformamide), have been synthesized and characterized. X-ray crystal structural data reveal that compound 1 crystallizes in triclinic space group P-1, a=9.716(3) A, b=12.193(3) A, c=12.576(3) A, {alpha}=62.19(2) Degree-Sign , {beta}=66.423(17) Degree-Sign , {gamma}=72.72(2) Degree-Sign , Z=2, while compound 2 crystallizes in monoclinic space group Cc, a=19.80(3) A, b=20.20(2) A, c=18.01(3) A, {beta}=108.40(4) Degree-Sign , Z=4. Variable-temperature magnetic susceptibilities of compounds 1 and 2 exhibit overall weak antiferromagnetic coupling between the adjacent Mn(II) ions. - Graphical abstract: Three-dimensional porous and two-dimensional layered manganese isophthalates have been prepared. Magnetic susceptibility measurements exhibit overall weak antiferromagnetic interactions between the Mn(II) ions in both compounds. Highlights: Black-Right-Pointing-Pointer Two manganese isophthalates have been prepared. Black-Right-Pointing-Pointer Compound 1 adopts a three-dimensional porous structure. Black-Right-Pointing-Pointer Compound 2 adopts a two-dimensional layered structure. Black-Right-Pointing-Pointer Magnetic properties of both compounds are investigated.

Chen Jinxi, E-mail: chenjinxi@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Wang Jingjing [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Ohba, Masaaki [Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka (Japan)

2012-01-15

283

Synthesis, crystal structure, and properties of a double-helical zinc(II) coordination polymer with Ozagrel drug  

NASA Astrophysics Data System (ADS)

By the reaction of Zn(OAc) 2·2H 2O with Ozagrel, ( E)-3-(4-((1 H-imidazol-1-yl)methyl)phenyl)acrylic acid (Himpaa), a novel coordination polymer [Zn(impaa) 2] n(1) was synthesized and was characterized by IR, elemental analysis, single-crystal X-ray diffraction analysis, photoluminescence spectroscopy, and thermogravimetric and differential thermal analysis. The four-coordinate Zn(II) ions are linked into 1D double-helical chain by the deprotonated impaa -, which is extended into a 3D supramolecular structure through intermolecular C-H⋯O hydrogen bonds.

Yang, Wei-Chun; Zheng, Zhe-Bo; Sun, Hao-Ling; Wang, Ke-Zhi

2012-02-01

284

Solvothermal synthesis and structures of lanthanide-organic sandwich coordination polymers with 4,4?-biphenyldicarboxylic acid  

Microsoft Academic Search

First examples of lanthanide coordination polymers with 4,4?-biphenyldicarboxylic acid (4,4?-H2bpdc), Ln(4,4?-Hbpdc)(4,4?-bpdc)(H2O)2 (Ln=Pr(1), Eu(2), Gd(3)) and Er(4,4?-bpdc)1.5(H2O)2 (4) were prepared by the solvothermal synthesis. Crystallographic data show that complexes 1–3 are isostructural and each lanthanide(III) ion is coordinated to six 4,4?-Hbpdc ligands, and display 3D sandwich structure with lanthanide ion layers and organic ligand layers alternately linking up with each other.

Yi-Bo Wang; Wen-Juan Zhuang; Lin-Pei Jin; Shao-Zhe Lu

2004-01-01

285

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

286

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

287

Compressibility measurements of quasi-one-dimensional quantum wires.  

PubMed

We report measurements of the compressibility of a one-dimensional quantum wire, defined in the upper well of a GaAs/AlGaAs double quantum well heterostructure. A wire defined simultaneously in the lower well probes the ability of the upper wire to screen the electric field from a biased surface gate. The technique is sensitive enough to resolve spin splitting of the subbands in the presence of an in-plane magnetic field. We measure a compressibility signal due to the 0.7 structure and study its evolution with increasing temperature and magnetic field. We see no evidence of the formation of the quasibound state predicted by the Kondo model, instead our data are consistent with theories which predict that the 0.7 structure arises as a result of spontaneous spin polarization. PMID:22026783

Smith, L W; Hamilton, A R; Thomas, K J; Pepper, M; Farrer, I; Griffiths, J P; Jones, G A C; Ritchie, D A

2011-09-16

288

Compressibility Measurements of Quasi-One-Dimensional Quantum Wires  

NASA Astrophysics Data System (ADS)

We report measurements of the compressibility of a one-dimensional quantum wire, defined in the upper well of a GaAs/AlGaAs double quantum well heterostructure. A wire defined simultaneously in the lower well probes the ability of the upper wire to screen the electric field from a biased surface gate. The technique is sensitive enough to resolve spin splitting of the subbands in the presence of an in-plane magnetic field. We measure a compressibility signal due to the 0.7 structure and study its evolution with increasing temperature and magnetic field. We see no evidence of the formation of the quasibound state predicted by the Kondo model, instead our data are consistent with theories which predict that the 0.7 structure arises as a result of spontaneous spin polarization.

Smith, L. W.; Hamilton, A. R.; Thomas, K. J.; Pepper, M.; Farrer, I.; Griffiths, J. P.; Jones, G. A. C.; Ritchie, D. A.

2011-09-01

289

One-dimensional transport of In2O3 nanowires  

NASA Astrophysics Data System (ADS)

The gate-dependent one-dimensional transport of single-crystal In2O3 nanowire field effect transistors is studied at low temperature by measuring current (I-V) and differential conductance (dIds/dVds). At a smaller positive gate bias, gaps at near-zero source-drain bias were observed for both current and differential conductance spectra due to the absence of the density of states in the source-drain energy window for a small Vds. The transport can be explained using conventional low-temperature field effect transistor theory. On the other hand, at a large gate bias when the Fermi energy of the nanowire moves up into its conduction band, the differential conductance of the semiconducting In2O3 nanowire exhibits zero-bias anomalies, following a power-law behavior.

Liu, Fei; Bao, Mingqiang; Wang, Kang L.; Li, Chao; Lei, Bo; Zhou, Chongwu

2005-05-01

290

Dielectric environment mediated quantum screening of one dimensional electron gas  

E-print Network

Relaxing the assumption of "infinite and homogenous background" the dielectric response function of one-dimensional (1D) semiconducting nanowires embedded in a dielectric environment is calculated. It is shown that high-k (higher than semiconductor dielectric constant) dielectric environment reduces the screening by the free carriers inside the nanostructure whereas, low dielectric environment increases the Coulombic interaction between free carriers and enhances the strength of screening function. In long wavelength limit, dielectric screening and collective excitation of electron gas are found to be solely determined by the environment instead of the semiconductor. Behavior of static dielectric function is particularly addressed at a specific wavevector q=2k_F; a wavevector ubiquitously appears in charge transport in nanostructures

Aniruddha Konar; Tian Fang; Debdeep Jena

2011-02-15

291

Erosion by a one-dimensional random walk  

NASA Astrophysics Data System (ADS)

We consider a model introduced by Baker et al. [Phys. Rev. E 88, 042113 (2013), 10.1103/PhysRevE.88.042113] of a single lattice random walker moving on a domain of allowed sites, surrounded by blocked sites. The walker enlarges the allowed domain by eroding the boundary at its random encounters with blocked boundary sites: attempts to step onto blocked sites succeed with a given probability and convert these sites to allowed sites. The model interpolates continuously between the Pólya random walker on the one-dimensional lattice and a "blind" walker who attempts freely, but always aborts, moves to blocked sites. We obtain some exact results about the walker's location and the rate of erosion.

Chisholm, Rebecca H.; Hughes, Barry D.; Landman, Kerry A.

2014-08-01

292

Light Field Distributions in One-dimensional Photonic Crystal Fibers  

E-print Network

It is shown in this paper that the light field distribution in a band gap within periodic structures for one-dimensional photonic crystal fibers is described by a decaying factor multiplied by a periodical function that has the same period length as the one of the medium or has double the period length of the medium, depending on the sign of the trace of eigen value matrix. This fundamental property is applicable to any 1D planar periodic structures, no matter how many layers a unit cell has, what the contrast of refractive indices is, and whether the dielectric parameters in individual layers are homogeneous or inhomogeneous; it plays a significant role in understanding of numerical results in a number of previously published research works. It is also shown that, similar to the refractive index guidance in conventional optical fibers, the photonic band gap guidance is also a form of total internal reflection.

Changbiao Wang

2010-07-16

293

Finite one-dimensional impenetrable Bose systems: Occupation numbers  

SciTech Connect

Bosons in the form of ultracold alkali-metal atoms can be confined to a one-dimensional (1D) domain by the use of harmonic traps. This motivates the study of the ground-state occupations {lambda}{sub i} of effective single-particle states {phi}{sub i}, in the theoretical 1D impenetrable Bose gas. Both the system on a circle and the harmonically trapped system are considered. The {lambda}{sub i} and {phi}{sub i} are the eigenvalues and eigenfunctions, respectively, of the one-body density matrix. We present a detailed numerical and analytic study of this problem. Our main results are the explicit scaled forms of the density matrices, from which it is deduced that for fixed i the occupations {lambda}{sub i} are asymptotically proportional to {radical}(N) in both the circular and harmonically trapped cases.

Forrester, P.J. [Department of Mathematics and Statistics, University of Melbourne, Victoria 3010 (Australia); Frankel, N.E.; Garoni, T.M. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Witte, N.S. [Department of Mathematics and Statistics, University of Melbourne, Victoria 3010 (Australia); School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia)

2003-04-01

294

One-dimensional plasma photonic crystals with sinusoidal densities  

NASA Astrophysics Data System (ADS)

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.; Shang, L.; Zhang, S.

2014-01-01

295

Bandgap characteristics of one-dimensional plasma photonic crystal  

SciTech Connect

When two pump laser pulses intersect in an underdense plasma, plasma Bragg grating (PBG) is induced by the slow-varying ponderomotive force [Z. M. Sheng et al., Appl. Phys. B: Lasers Opt. 77, 673 (2003)]. Such a PBG can be considered as a one-dimensional (1D) plasma photonic crystal (PPC). Here the bandgap characteristic of 1D PPC composed of plasma layers of different densities is investigated theoretically and numerically. It is found that when the maximum density is lower than the critical density of the pump laser, there is only one normal-incidence bandgap. When the maximum density is higher than the critical density of the pump laser, high-order bandgaps are found. The theoretical results are verified by 1D particle-in-cell simulations.

Yin Yan; Ma Yanyun; Tian Chenglin; Shao Fuqiu [Institute of Science, National University of Defense Technology, Changsha 410073 (China); Xu Han; Zhuo Hongbin [Institute of Computer Science, National University of Defense Technology, Changsha 410073 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institut fuer Theoretische Physik I, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

2009-10-15

296

Kondo Polarons in a One-Dimensional Fermi Gas  

SciTech Connect

We consider the motion of a spin-1/2 impurity in a one-dimensional gas of spin-1/2 fermions. For antiferromagnetic interaction between the impurity and the fermions, the low temperature behavior of the system is governed by the two-channel Kondo effect, leading to the impurity becoming completely opaque to the spin excitations of the gas. As well as the known spectral signatures of the two-channel Kondo effect, we find that the low temperature mobility of the resulting 'Kondo polaron' takes the universal form {mu}{yields}3({Dirac_h}/2{pi})v{sub F}{sup 2}/2{pi}k{sub B}{sup 2}T{sup 2}, in sharp contrast to the spinless case where {mu}{proportional_to}T{sup -4}.

Lamacraft, Austen [Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714 (United States)

2008-11-28

297

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

298

Friction-induced oscillatory behaviour of one-dimensional detonations  

NASA Astrophysics Data System (ADS)

This paper studied the feasibility of the propagation of a steady detonation wave in rough tubes, based on the unsteady quasi-one-dimensional reactive Euler equations with frictional drag. The analysis showed that a competition between the rate of the chemical energy release and the rate of energy dissipation induced by friction drives a detonation in general towards instability. A steady wave solution can exist only when the unsteady downstream flow matches the upstream flow at the sonic locus where this energy rate competition is balanced. This criterion can be satisfied in the presence of low frictional drag. For large frictional drag, the competing effect of the chemical energy release and the momentum loss results in an oscillatory detonation and a steady wave solution does not exist.

Zhang, Fan; Lee, John H. S.

1994-07-01

299

Quasi one dimensional transport in individual electrospun composite nanofibers  

NASA Astrophysics Data System (ADS)

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 ?bulk ˜ 0.06 which agrees with theoretical predictions.

Avnon, A.; Wang, B.; Zhou, S.; Datsyuk, V.; Trotsenko, S.; Grabbert, N.; Ngo, H.-D.

2014-01-01

300

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

301

Interlayer magnetoresistance of quasi-one-dimensional layered organic conductors.  

PubMed

We studied the interlayer magnetoresistance of the representative quasi-one-dimensional (Q1D) layered organic conductor, (TMTSF)2PF6, over the full range of magnetic field orientations in three dimensions, and constructed a stereographic conductivity plot. Our results show that the previously reported angular-dependent magnetoresistance phenomena in Q1D conductors are closely related to one another in intermediate field orientations. Based on a comparison with theories, we can conclude that the Lebed resonance is the only fundamental effect and that other effects result from the modulation of the Lebed resonance amplitude. Most of the observed phenomena can be explained within the framework of the conventional Fermi liquid; however, the anomalous enhancement of the interlayer conductivity under a field parallel to the conducting planes suggests the existence of a new electron state. PMID:17678182

Kang, W; Osada, T; Jo, Y J; Kang, Haeyong

2007-07-01

302

One-dimensional simulations of reversed field pinch discharges  

NASA Astrophysics Data System (ADS)

A simple one-dimensional time-dependent model for simulating the magnetic field profiles in a reversed field pinch (RFP) plasma is presented. The model, which is derived from basic MHD equations with the addition of a phenomenological dynamo electric field, is able, through the tuning of a few free parameters, to simulate the time evolution of RFP discharges in a large range of operating conditions, successfully reproducing quantities such as the average toroidal field, the loop voltage and the on-axis safety factor. The application to several experimental conditions obtained on the RFX-mod machine [P. Sonato et al., Fusion Eng. Des. 66, 161 (2003)], including oscillating poloidal current drive (OPCD) is shown and the simulation outcome is discussed.

Martines, E.; Spagnolo, S.

2008-12-01

303

Wigner quantization of some one-dimensional Hamiltonians  

SciTech Connect

Recently, several papers have been dedicated to the Wigner quantization of different Hamiltonians. In these examples, many interesting mathematical and physical properties have been shown. Among those we have the ubiquitous relation with Lie superalgebras and their representations. In this paper, we study two one-dimensional Hamiltonians for which the Wigner quantization is related with the orthosymplectic Lie superalgebra osp(1|2). One of them, the Hamiltonian H=xp, is popular due to its connection with the Riemann zeros, discovered by Berry and Keating on the one hand and Connes on the other. The Hamiltonian of the free particle, H{sub f}=p{sup 2}/2, is the second Hamiltonian we will examine. Wigner quantization introduces an extra representation parameter for both of these Hamiltonians. Canonical quantization is recovered by restricting to a specific representation of the Lie superalgebra osp(1|2).

Regniers, G.; Van der Jeugt, J. [Department of Applied Mathematics and Computer Science, Ghent University, Krijgslaan 281-S9, B-9000 Gent (Belgium)

2010-12-15

304

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

305

Entanglement dynamics in one-dimensional quantum cellular automata  

SciTech Connect

Several proposed schemes for the physical realization of a quantum computer consist of qubits arranged in a cellular array. In the quantum circuit model of quantum computation, an often complex series of two-qubit gate operations is required between arbitrarily distant pairs of lattice qubits. An alternative model of quantum computation based on quantum cellular automata (QCA) requires only homogeneous local interactions that can be implemented in parallel. This would be a huge simplification in an actual experiment. We find some minimal physical requirements for the construction of unitary QCA in a one-dimensional Ising spin chain and demonstrate optimal pulse sequences for information transport and entanglement distribution. We also introduce the theory of nonunitary QCA and show by example that nonunitary rules can generate environment assisted entanglement.

Brennen, Gavin K.; Williams, Jamie E. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)

2003-10-01

306

Feedback-induced oscillations in one-dimensional colloidal transport.  

PubMed

We investigate a driven, one-dimensional system of colloidal particles in a periodically corrugated narrow channel subject to a time-delayed feedback control. Our goal is to identify conditions under which the control induces oscillatory, time-periodic states. The investigations are based on the Fokker-Planck equation involving the density distribution of the system. First, by using the numerical continuation technique, we determine the linear stability of a stationary density. Second, the nonlinear regimes are analyzed by studying numerically the temporal evolution of the first moment of the density distribution. In this way we construct a bifurcation diagram revealing the nature of the instability. Apart from the case of a system with periodic boundary conditions, we also consider a microchannel of finite length. Finally, we study the influence of (repulsive) particle interactions based on dynamical density functional theory. PMID:23214782

Lichtner, K; Pototsky, A; Klapp, S H L

2012-11-01

307

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

308

Topologically Protected States in One-Dimensional Systems  

E-print Network

We study a class of periodic Schr\\"odinger operators, which we prove have Dirac points. We then show that the introduction of an "edge" via adiabatic modulation of a periodic potential by a domain wall results in the bifurcation of spatially localized "edge states", associated with the topologically protected zero-energy mode of an asymptotic one-dimensional Dirac operator. The bound states we construct can be realized as highly robust TM- electromagnetic modes for a class of photonic waveguides with a phase-defect. Our model also captures many aspects of the phenomenon of topologically protected edge states for two-dimensional bulk structures such as the honeycomb structure of graphene.

Charles L. Fefferman; James P. Lee-Thorp; Michael I. Weinstein

2014-05-19

309

One-dimensional topological edge states of bismuth bilayers  

NASA Astrophysics Data System (ADS)

The hallmark of a topologically insulating state of matter in two dimensions protected by time-reversal symmetry is the existence of chiral edge modes propagating along the perimeter of the sample. Among the first systems predicted to be a two-dimensional topological insulator are bilayers of bismuth. Here we report scanning tunnelling microscopy experiments on bulk Bi crystals that show that a subset of the predicted Bi-bilayers' edge states are decoupled from the states of the substrate and provide direct spectroscopic evidence of their one-dimensional nature. Moreover, by visualizing the quantum interference of edge-mode quasi-particles in confined geometries, we demonstrate their remarkable coherent propagation along the edge with scattering properties consistent with strong suppression of backscattering as predicted for the propagating topological edge states.

Drozdov, Ilya K.; Alexandradinata, A.; Jeon, Sangjun; Nadj-Perge, Stevan; Ji, Huiwen; Cava, R. J.; Andrei Bernevig, B.; Yazdani, Ali

2014-09-01

310

Electronic properties of one-dimensional graphene bilayer ribbons  

NASA Astrophysics Data System (ADS)

The electronic properties of armchair and zigzag bilayer graphene nanoribbons are studied using ab-initio density functional theory. We study the effect of width and the electric fields (upto the dielectric breakdown field of SiO2) on their energy gaps [Sahu 2007]. We find metallic and semiconductor arm-chair ribbons and electric field has the effect of increasing the gap in metallic ribbons. The zigzag ribbons due to the edge magnetism show opposite behavior: gap decreases with increase in the applied electric field. We studied small ribbons (below 1 nm) as well as large ribbons (5 nm). In small width arm-chair semiconductor ribbons, the gap decreases whereas in the large width ribbons, the gap increases with applied electric field. Sahu B, Min H, MacDonald AH, and Banerjee SK ``Electronic properties of one-dimensional graphene bilayer ribbons'' (Submitted to Physical Review B).

Sahu, Bhagawan; Min, Hongki; MacDonald, Allan; Banerjee, Sanjay

2008-03-01

311

Quantum Fields bounded by one dimensional crystal plates  

E-print Network

We get deeper understanding of the role played by boundary conditions in quantum field theory, by studying the structure of a scalar massless quantum field theory bounded by two one dimensional planar crystal plates. The system can also be understood as a massless scalar confined to propagate in the surface of a finite cylinder. We classify the most general type of regular behaved boundary conditions that the quantum field can satisfy, in accordance with the unitarity principle of quantum field theory. Also, we characterize the frequency spectrum for each quantum field theory, by computing the holomorphic spectral function. The spectral function is the starting point to compute the Casimir energy as a global function over the space of allowed boundary conditions for the quantum field theory.

J. M. Munoz-Castaneda; M. Bordag

2011-04-27

312

The Asymmetric One-Dimensional Constrained Ising Model: Rigorous Results  

NASA Astrophysics Data System (ADS)

We study a one-dimensional spin (interacting particle) system, with product Bernoulli ( p) stationary distribution, in which a site can flip only when its left neighbor is in state +1. Such models have been studied in physics as simple exemplars of systems exhibiting slow relaxation. In our "East" model the natural conjecture is that the relaxation time ?( p), that is 1/(spectral gap), satisfies log ?( p)˜tfrac{{log ^2 (1/p)}}{{log 2}} as p?0. We prove this up to a factor of 2. The upper bound uses the Poincaré comparison argument applied to a "wave" (long-range) comparison process, which we analyze by probabilistic techniques. Such comparison arguments go back to Holley (1984, 1985). The lower bound, which atypically is not easy, involves construction and analysis of a certain "coalescing random jumps" process.

Aldous, David; Diaconis, Persi

2002-06-01

313

Photon propagation in a one-dimensional optomechanical lattice  

NASA Astrophysics Data System (ADS)

We consider a one-dimensional optomechanical lattice where each site is strongly driven by a control laser to enhance the basic optomechanical interaction. We then study the propagation of photons injected by an additional probe laser beam; this is the lattice generalization of the well-known optomechanically induced transparency (OMIT) effect in a single optomechanical cavity. We find an interesting interplay between OMIT-type physics and geometric, Fabry-Perot-type resonances. In particular, phononlike polaritons can give rise to high-amplitude transmission resonances which are much narrower than the scale set by internal photon losses. We also find that the local photon density of states in the lattice exhibits OMIT-style interference features. It is thus far richer than would be expected by just looking at the band structure of the dissipation-free coherent system.

Chen, Wei; Clerk, Aashish A.

2014-03-01

314

One-dimensional photonic crystals as selective back reflectors  

NASA Astrophysics Data System (ADS)

Using the sol-gel technology and dip-coating method involving the deposition of silica layers and titania layers, we have fabricated symmetrical structures with one-dimensional photonic crystals on both sides of glass substrates. For the structure with five bilayers (SiO2/TiO2) we have obtained the maximum reflectance of 0.967 for the wavelength ?r=493 nm and full width at half maximum of the main reflectance peak of FWHM=185 nm. The fabricated structures have been analyzed theoretically with the application of the transfer matrix 2×2 method, allowing for complex refraction indexes for the component layers. The paper presents the applied theoretical model and the discussion involving the calculated and experimental results. Good agreement between the calculation and experimental results has been obtained. The elaborated photonic structures can be applied in solar light concentrators for photovoltaic systems.

Gondek, Ewa; Karasi?ski, Pawe?

2013-06-01

315

Entropic topological invariant for a gapped one-dimensional system  

NASA Astrophysics Data System (ADS)

We propose an order parameter for a general one-dimensional gapped system with an open boundary condition. The order parameter can be computed from the ground state entanglement entropy of some regions near one of the boundaries. Hence, it is well defined even in the presence of arbitrary interaction and disorder. We also show that it is invariant under a finite-depth local quantum circuit, suggesting its stability against an arbitrary local perturbation that does not close the energy gap. Further, it can unambiguously distinguish a Majorana chain from a trivial chain under global fermion parity conservation. We argue that the order parameter can be, in principle, measured in an optical lattice system.

Kim, Isaac H.

2014-06-01

316

Topological invariants and interacting one-dimensional fermionic systems  

NASA Astrophysics Data System (ADS)

We study one-dimensional, interacting, gapped fermionic systems described by variants of the Peierls-Hubbard model, and we characterize their phases via a topological invariant constructed out of their Green's functions. We demonstrate that the existence of topologically protected, zero-energy states at the boundaries of these systems can be tied to the value of the topological invariant, just like when working with the conventional, noninteracting topological insulators. We use a combination of analytical methods and the numerical density matrix renormalization group method to calculate the values of the topological invariant throughout the phase diagrams of these systems, thus deducing when topologically protected boundary states are present. We are also able to study topological states in spin systems because, deep in the Mott insulating regime, these fermionic systems reduce to spin chains. In this way, we associate the zero-energy states at the end of an antiferromagnetic spin-1 Heisenberg chain with a topological invariant equal to 2.

Manmana, Salvatore R.; Essin, Andrew M.; Noack, Reinhard M.; Gurarie, Victor

2012-11-01

317

Transport through quasi-one-dimensional wires with correlated disorder  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

318

Ordering phenomena in quasi-one-dimensional organic conductors.  

PubMed

Low-dimensional organic conductors could establish themselves as model systems for the investigation of the physics in reduced dimensions. In the metallic state of a one-dimensional solid, Fermi liquid theory breaks down and spin and charge degrees of freedom become separated. But the metallic phase is not stable in one dimension: as the temperature is reduced, the electronic charge and spin tend to arrange themselves in an ordered fashion due to strong correlations. The competition of the different interactions is responsible for which broken-symmetry ground state is eventually realized in a specific compound and which drives the system toward an insulating state. Here, we review the various ordering phenomena and how they can be identified by optic and magnetic measurements. While the final results might look very similar in the case of a charge density wave and a charge-ordered metal, for instance, the physical cause is completely different. When density waves form, a gap opens in the density of states at the Fermi energy due to nesting of the one-dimension Fermi surface sheets. When a one-dimensional metal becomes a charge-ordered Mott insulator, on the other hand, the short-range Coulomb repulsion localizes the charge on the lattice sites and even causes certain charge patterns. We try to point out the similarities and conceptional differences of these phenomena and give an example for each of them. Particular emphasis will be put on collective phenomena that are inherently present as soon as ordering breaks the symmetry of the system. PMID:17479236

Dressel, Martin

2007-07-01

319

New Zn(2+) coordination polymers constructed from acylhydrazidate molecules: synthesis and structural characterization.  

PubMed

By employing two types of hydrothermal in situ ligand reactions (acylation of N2H4 with aromatic polycarboxylic acids, reduction of 3-nitrophthalhydrazide by N2H4), three new acylhydrazidate-extended Zn(2+) coordination polymers [Zn2(3-apth)(atrz)2] (3-apth = 3-aminophthalhydrazidate; atrz = 3-amino-1,2,4-triazolate) , [Zn2(4-apth)(atez)2] (4-apth = 4-aminophthalhydrazidate; atez = 5-aminotetrazolate) , and [Zn(3-cppth)(H2O)] (3-cppth = 4-(3-carboxyphenoxy)phthalhydrazidate) were obtained. X-ray single-crystal diffraction analysis revealed that (i) compound possesses a 3-D structure. The triazolate molecules link the Zn(2+) ions to form a 2-D layer with a (6,3) topology. Then the acylhydrazidate molecule acts as the second linker, extending the (6,3) nets into a 3-D network of compound ; (ii) compound also exhibits a 3-D structure. The acylhydrazidate molecules first link the Zn(2+) ions into a 1-D infinite chain. The tetrazolate molecules propagate further the chains into a 3-D (4,4)-connected net (symbol: (4·6(4)·8)2(4(2)·6(2)·8(2))); (iii) compound only shows a 1-D chain structure. The photoluminescence analysis indicates that the three title compounds all emit light, especially compound which emits extremely strong blue light. The side group on the phthalhydrazidate molecule plays a crucial role in the emission behaviors of compounds . At 77 K, the activated compound can adsorb N2 with a capacity of ca. 41.0 cm(3) g(-1). PMID:25208479

Wang, Yan-Ning; Li, Guang-Hua; Bai, Fu-Quan; Yu, Jie-Hui; Xu, Ji-Qing

2014-09-30

320

Synthesis and structure of solution-stable one-dimensional palladium wires  

NASA Astrophysics Data System (ADS)

One-dimensional metal wires are valuable materials because of their optical and electronic anisotropy, and they have potential utility in devices such as photovoltaic cells and molecular sensors. However, despite more than a century of research, only a few examples exist of well-defined one-dimensional (1D) metal wires that allow for the rational variation of conductivity. Herein we describe the first examples of 1D molecular wires supported by Pd-Pd bonds, the thin-film conductive properties of which can be altered by controlled molecular changes. Wires based on Pd(III) give semiconducting films with a modifiable bandgap, whereas wires based on Pd(2.5) give films that display metallic conductivity above 200 K: a metallic state has not been reported previously for any polymer composed of 1D metal wires. The wires are infinite in the solid state and maintain 1D structures in solution with lengths of up to 750 nm. Solution stability enables thin film coating, a requisite for device fabrication using molecular wires.

Campbell, Michael G.; Powers, David C.; Raynaud, Jean; Graham, Michael J.; Xie, Ping; Lee, Eunsung; Ritter, Tobias

2011-12-01

321

Fullerene-based one-dimensional crystalline nanopolymer formed through topochemical transformation of the parent nanowire  

NASA Astrophysics Data System (ADS)

Large-scale practical applications of fullerene (C60) in nanodevices could be significantly facilitated if the commercially available micrometer-scale raw C60 powder were further processed into a one-dimensional nanowire-related polymer displaying covalent bonding as molecular interlinks and resembling traditional important conjugated polymers. However, there has been little study thus far in this area despite the abundant literature on fullerene. Here we report the preparation and characterization of such a C60 -based polymer nanowire, (-C60TMB-)n , where TMB=1,2,4 -trimethylbenzene, which displays a well-defined crystalline nanostructure, exceptionally large length-to-width ratio and excellent thermal stability. The material is prepared by first growing the corresponding nanowire through a solution phase of C60 followed by a topochemical polymerization reaction in the solid state. Gas chromatography, mass spectrometry and C13 nuclear magnetic resonance evidence is provided for the nature of the covalent bonding mode adopted by the polymeric chains. Theoretical analysis based on detailed calculations of the reaction energetics and structural analysis provides an in-depth understanding of the polymerization pathway. The nanopolymer promises important applications in biological fields and in the development of optical, electrical, and magnetic nanodevices.

Geng, Junfeng; Solov'Yov, Ilia A.; Reid, David G.; Skelton, Paul; Wheatley, Andrew E. H.; Solov'Yov, Andrey V.; Johnson, Brian F. G.

2010-06-01

322

Synthesis, structures and properties of two metal-organic coordination polymers derived from manganese(??), thiabendazole and polydentate carboxylic acids.  

PubMed

Two novel binuclear Mn(II) metal-organic coordination complexes [Mn2(TBZ)2(CDC)(C2O4)]n (1), {[Mn2(TBZ)2(BDC)(0.5)(BTC)(H2O)2]·ET}n (2), (where TBZ = thiabendazole, H2CDC = trans-1,4-cyclohexanedicarboxylic acid, H2C2O4 = oxalic acid, H3BTC = 1,3,5-benzenetricarboxylic acid, ET = ethanol, H2BDC = 1,4-benzenedicarboxylate) have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, electrochemical analysis and single crystal X-ray diffraction. The X-ray structure analysis reveals that 1 is s two-dimensional layer and 2 is s one-dimensional chain. In complex 1, it reveals 2-D layers composed of multi-(bidentate) bridging ligands (CDC and C2O4), and in 2, the coordinated BTC ligands adopt a monodentate mode and with BDC ligands adopt alternately chelating Mn1 and Mn2 bridges into 1-D chains. The 3-D structures of the two complexes are stabilized by ?-? stacking interactions and hydrogen bonds. PMID:24317523

Liang, Peng; Xia, Wen-Xiu; Tian, Wei-Man; Yin, Xian-Hong

2013-01-01

323

Exploring control of cadmium halide coordination polymers via control of cadmium(II) coordination sites utilizing short multidentate ligands  

NASA Astrophysics Data System (ADS)

The goal of this project has been to determine the capability of a number of linear multidentate ligands to induce extended structures in cadmium halides. Metal salts of the form CdX 2 (X=Cl, Br, I), and for comparison Cd(NO 3) 2, were complexed with diethylene glycol (EO2), triethylene glycol monomethyl ether (EO3Me), triethylene glycol dimethyl ether (a glyme, EG3), diethylene triamine (EN2), and 1,3-propylenediamine (PN1). The crystal structures of 11 resulting complexes were structurally characterized including: [Cd(EO2) 3][Cd 2I 6], [Cd(EN2) 2]Cl 2·H 2O, [Cd(EN2) 2]Br 2, [Cd(EN2) 2][CdI 4], [CdCl 2(EO3Me)] 2, [CdBr 2(EO3Me)] 2, [Cd(NO 3) 2(EO3Me)], [(CdCl 2) 2(EG3)] n, [(CdBr 2) 2(EG3)] n, [CdI 2(EG3)], and [CdI 2(PN1)] n. While each structure is interesting in its own right, the continued observance of a wide variety of coordination modes for such similar ligands does little to help improve the predictability of simple Cd 2+ coordination compounds.

Hines, C. Corey; Reichert, W. Matthew; Griffin, Scott T.; Bond, Andrew H.; Snowwhite, Paul E.; Rogers, Robin D.

2006-08-01

324

Polymer complexes. LIV. Structural and spectral studies of supramolecular coordination polymers built from Ni(II), Fe(II) and Pd(II) with sulphadrug  

NASA Astrophysics Data System (ADS)

Polymer complexes of p-acrylamidyl sulphaguanidine (HL) with Ni(II), Fe(II) and Pd(II) salts have been prepared. The structures of the polymer complexes were elucidated using elemental analysis, 1H NMR, UV-Vis, IR spectroscopies, magnetic moment, molar conductance and thermal analysis. The polymer complexes were isolated in 1:1 and 1:2 (M:L) ratios. The solid monocomplexes (1:1) (M:L) were isolated in the general formula [Fe(HL)O 2SO 2(OH 2) 2]. The biscomplexes (1:2) (M:L) solid chelates found to have the general formula [Ni(HL) 2X 2] n (X = Cl -, Br -, I -, NO3-, NCS -), [Fe(HL)(en)(OSO 3)(OH 2)] n and [Ni(HL) 2(Py) 2] nX 2, while {[Pd(L)X] 2} n (1:1) (X = Cl - or Br -). In all the polymer complexes the ligand and anions were found to be coordinated to the Ni(II) and Fe(II) ions. The bidentate nature of the ligand is evident from IR spectra. The magnetic and spectroscopic data indicate a octahedral geometry for complexes. The thermal behaviour of these chelates shows that the hydrated complexes loss water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps.

El-Sonbati, A. Z.; Belal, A. A. M.; Diab, M. A.; Mohamed, R. H.

2011-03-01

325

One-dimensional flows of an imperfect diatomic gas  

NASA Technical Reports Server (NTRS)

With the assumptions that Berthelot's equation of state accounts for molecular size and intermolecular force effects, and that changes in the vibrational heat capacities are given by a Planck term, expressions are developed for analyzing one-dimensional flows of a diatomic gas. The special cases of flow through normal and oblique shocks in free air at sea level are investigated. It is found that up to a Mach number 10 pressure ratio across a normal shock differs by less than 6 percent from its ideal gas value; whereas at Mach numbers above 4 the temperature rise is considerable below and hence the density rise is well above that predicted assuming ideal gas behavior. It is further shown that only the caloric imperfection in air has an appreciable effect on the pressures developed in the shock process considered. The effects of gaseous imperfections on oblique shock-flows are studied from the standpoint of their influence on the life and pressure drag of a flat plate operating at Mach numbers of 10 and 20. The influence is found to be small. (author)

1959-01-01

326

Dynamical Stability of a One-dimensional Plasma  

NASA Astrophysics Data System (ADS)

Since the days of the early computers, computer simulations have been incredibly important to the study of the motion of systems of particles as a way to model such systems as stars in a galaxy or charges in plasmas, which cannot be physically produced in a laboratory. These models are still used today, to the great benefit of the scientific community. In this study, the interaction of a one-dimensional system of charges with periodic boundary conditions is modeled with a computer simulation using an Euler integration technique. The chaos in a particular system is then studied through the computation of the largest Lyapunov exponent for that system. It is revealed that the value for this largest exponent, while independent of the initial conditions for a particular system, is dependent upon the size of the system, i.e. the number of particles in the system, as well as the charge-to-mass ratio of these particles. We will present the results of different computer simulations to demonstrate these dependencies by graphing intermediate averages for the greatest Lyapunov exponents over time for a set of systems of either different sizes, or with different charge-to-mass ratios.

Roberts, Matthew; Miller, Bruce

2011-10-01

327

One-dimensional surface phonon polaritons in boron nitride nanotubes  

NASA Astrophysics Data System (ADS)

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.

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.

2014-08-01

328

Critical velocity of a clean one-dimensional superconductor  

NASA Astrophysics Data System (ADS)

We revisit the problem of critical velocity of a clean one-dimensional superconductor. At the level of mean-field theory, we find that the zero-temperature value of the critical velocity—the uniform velocity of the superfluid condensate at which the superconducting state becomes unstable—is a factor of 2 smaller than the Landau critical velocity. This is in contrast to a prior finding, which held that the critical velocity is equal to the Landau critical velocity. The smaller value of the critical velocity, which our analysis yields, is the result of a pre-emptive Clogston-Chandrasekhar-type discontinuous phase transition, and is an analog of the threshold value of the uniform exchange field of a superconductor previously investigated by Sarma [J. Phys. Chem. Solids 24, 1029 (1963)] and by Maki and Tsuneto [Prog. Theor. Phys. 31, 945 (1964)]. We also consider the impact of nonzero temperature, study critical currents, and examine metastability and its limits in the temperature versus flow-velocity phase diagram. In addition, we comment on the effects of electron scattering by impurities.

Wei, Tzu-Chieh; Goldbart, Paul M.

2009-10-01

329

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

330

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

331

Multi-band design for one-dimensional phononic crystals  

NASA Astrophysics Data System (ADS)

Periodic composites with band gaps that prevent the propagation of elastic waves in certain frequency ranges can be used to control waves for a variety of engineering applications. Although studies on the characteristics of these materials, which are called phononic crystals (PCs), have yielded a large number of positive results in recent years, there is still a lack of effective design methods. In this work, a multi-objective optimization approach based on the band gap mechanism and an intelligent algorithm is used to design a one-dimensional (1D) slab construction of PCs. The design aims to fit pre-determined bands by arranging the available materials properly. Obtained by analyzing the wave transmission in periodic layers, the objective functions are linked to the optimization program to obtain a proper solution set. The results of the numerical simulations demonstrate that without constructing complicated structures, the design method is able to produce PCs that overcome the limitations of two-component PCs and hence can feasibly and effectively achieve the design targets. The design approach presented in this paper can be extended to two- or three-dimensional systems and has great potential for the development of sound/ultrasound isolation structures, multiple band frequency filters, and other applications.

Zhang, Pei; Wang, ZhenYu; Zhang, YongQiang; Liang, Xu

2013-07-01

332

Index theory of one dimensional quantum walks and cellular automata  

E-print Network

If a one-dimensional quantum lattice system is subject to one step of a reversible discrete-time dynamics, it is intuitive that as much "quantum information" as moves into any given block of cells from the left, has to exit that block to the right. For two types of such systems - namely quantum walks and cellular automata - we make this intuition precise by defining an index, a quantity that measures the "net flow of quantum information" through the system. The index supplies a complete characterization of two properties of the discrete dynamics. First, two systems S_1, S_2 can be pieced together, in the sense that there is a system S which locally acts like S_1 in one region and like S_2 in some other region, if and only if S_1 and S_2 have the same index. Second, the index labels connected components of such systems: equality of the index is necessary and sufficient for the existence of a continuous deformation of S_1 into S_2. In the case of quantum walks, the index is integer-valued, whereas for cellular automata, it takes values in the group of positive rationals. In both cases, the map S -> ind S is a group homomorphism if composition of the discrete dynamics is taken as the group law of the quantum systems. Systems with trivial index are precisely those which can be realized by partitioned unitaries, and the prototypes of systems with non-trivial index are shifts.

D. Gross; V. Nesme; H. Vogts; R. F. Werner

2009-10-20

333

One-dimensional simulation of lanthanide isotachophoresis using COMSOL.  

PubMed

Electrokinetic separations can be used to quickly separate rare earth metals to determine their forensic signature. In this work, we simulate the concentration and separation of trivalent lanthanide cations by isotachophoresis. A one-dimensional simulation is developed using COMSOL v4.0a, a commercial finite element simulator, to represent the isotachophoretic separation of three lanthanides: lanthanum, terbium, and lutetium. The binding ligand chosen for complexation with the lanthanides is ?-hydroxyisobutyric acid (HIBA) and the buffer system includes acetate, which also complexes with the lanthanides. The complexes formed between the three lanthanides, HIBA, and acetate are all considered in the simulation. We observe that the presence of only lanthanide:HIBA complexes in a buffer system with 10 mM HIBA causes the slowest lanthanide peak (lutetium) to split from the other analytes. The addition of lanthanide:acetate complexes into the simulation of the same buffer system eliminates this splitting. Decreasing the concentration of HIBA in the buffer to 7 mM causes the analyte stack to migrate faster through the capillary. PMID:22522543

Dixon, Derek R; Clark, Sue B; Ivory, Cornelius F

2012-03-01

334

Phonons in a one-dimensional microfluidic crystal  

E-print Network

The development of a general theoretical framework for describing the behaviour of a crystal driven far from equilibrium has proved difficult1. Microfluidic crystals, formed by the introduction of droplets of immiscible fluid into a liquid-filled channel, provide a convenient means to explore and develop models to describe non-equilibrium dynamics2, 3, 4, 5, 6, 7, 8, 9, 10, 11. Owing to the fact that these systems operate at low Reynolds number (Re), in which viscous dissipation of energy dominates inertial effects, vibrations are expected to be over-damped and contribute little to their dynamics12, 13, 14. Against such expectations, we report the emergence of collective normal vibrational modes (equivalent to acoustic 'phonons') in a one-dimensional microfluidic crystal of water-in-oil droplets at Reapprox10-4. These phonons propagate at an ultra-low sound velocity of approx100 mum s-1 and frequencies of a few hertz, exhibit unusual dispersion relations markedly different to those of harmonic crystals, and give rise to a variety of crystal instabilities that could have implications for the design of commercial microfluidic systems. First-principles theory shows that these phonons are an outcome of the symmetry-breaking flow field that induces long-range inter-droplet interactions, similar in nature to those observed in many other systems including dusty plasma crystals15, 16, vortices in superconductors17, 18, active membranes19 and nucleoprotein filaments20.

Tsevi Beatus; Tsvi Tlusty; Roy Bar-Ziv

2010-08-06

335

Index Theory of One Dimensional Quantum Walks and Cellular Automata  

NASA Astrophysics Data System (ADS)

If a one-dimensional quantum lattice system is subject to one step of a reversible discrete-time dynamics, it is intuitive that as much "quantum information" as moves into any given block of cells from the left, has to exit that block to the right. For two types of such systems — namely quantum walks and cellular automata — we make this intuition precise by defining an index, a quantity that measures the "net flow of quantum information" through the system. The index supplies a complete characterization of two properties of the discrete dynamics. First, two systems S 1, S 2 can be "pieced together", in the sense that there is a system S which acts like S 1 in one region and like S 2 in some other region, if and only if S 1 and S 2 have the same index. Second, the index labels connected components of such systems: equality of the index is necessary and sufficient for the existence of a continuous deformation of S 1 into S 2. In the case of quantum walks, the index is integer-valued, whereas for cellular automata, it takes values in the group of positive rationals. In both cases, the map {S mapsto ind S} is a group homomorphism if composition of the discrete dynamics is taken as the group law of the quantum systems. Systems with trivial index are precisely those which can be realized by partitioned unitaries, and the prototypes of systems with non-trivial index are shifts.

Gross, D.; Nesme, V.; Vogts, H.; Werner, R. F.

2012-03-01

336

Spontaneous Growth of Quasi-One-Dimensional Silver Filaments  

NASA Astrophysics Data System (ADS)

Quasi-one-dimensional silver filaments spontaneously grow on power contacts of electrical apparatus in corrosive industrial atmosphere. Though hazardous phenomenon has been seen from 1920s and caused a number of violent failures, it was practically neither studied nor understood. The major environmental factor to initiate the growth is relatively low concentration of H_2S. In electrical apparatus, conductive parts are usually made of Cu with relatively thin Ag plating ( ~10 ?m) with both base metal and plating corroding in such environment. As soon as a thick enough layer of Ag_2S has been formed, the new process of growing thin filaments (whiskers) spontaneously begins in certain places exposed to H_2S. The filaments grow virtually everywhere but most intense growth is found in locations having elevated temperature while electrical units are energized. Morphology and chemical composition of the filaments have been determined by SEM/EDS technique. The sizes of the filaments are ranging from miniscule (several ?m long), up to 10 cm long and 1 mm thick. Previous study shows that at specific conditions the rate of growth may reach 1mm/hr. Most of the whiskers are made of 97-99 % Ag with 1-3 % of Cu with the color depending on copper content. The major factors initiating, supporting and accelerating the mechanism of whisker growth have been investigated.

Helmer Chudnovsky, Bella

2002-03-01

337

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

338

New insights from one-dimensional spin glasses  

NASA Astrophysics Data System (ADS)

The concept of replica symmetry breaking found in the solution of the mean-field Sherrington-Kirkpatrick spinglass model has been applied to a variety of problems in science ranging from biological to computational and even financial analysis. Thus it is of paramount importance to understand which predictions of the mean-field solution apply to non-mean-field systems, such as realistic short-range spin-glass models. The one-dimensional spin glass with random power-law interactions promises to be an ideal test-bed to answer this question: Not only can large system sizes-which are usually a shortcoming in simulations of high-dimensional short-range system-be studied, by tuning the power-law exponent of the interactions the universality class of the model can be continuously tuned from the mean-field to the short-range universality class. We present details of the model, as well as recent applications to some questions of the physics of spin glasses. First, we study the existence of a spin-glass state in an external field. In addition, we discuss the existence of ultrametricity in short-range spin glasses. Finally, because the range of interactions can be changed, the model is a formidable test-bed for optimization algorithms.

Katzgraber, Helmut G.; Hartmann, Alexander K.; Young, A. P.

339

Validation and Comparison of One-Dimensional Graound Motion Methodologies  

SciTech Connect

Both point- and finite-source stochastic one-dimensional ground motion models, coupled to vertically propagating equivalent-linear shear-wave site response models are validated using an extensive set of strong motion data as part of the Yucca Mountain Project. The validation and comparison exercises are presented entirely in terms of 5% damped pseudo absolute response spectra. The study consists of a quantitative analyses involving modeling nineteen well-recorded earthquakes, M 5.6 to 7.4 at over 600 sites. The sites range in distance from about 1 to about 200 km in the western US (460 km for central-eastern US). In general, this validation demonstrates that the stochastic point- and finite-source models produce accurate predictions of strong ground motions over the range of 0 to 100 km and for magnitudes M 5.0 to 7.4. The stochastic finite-source model appears to be broadband, producing near zero bias from about 0.3 Hz (low frequency limit of the analyses) to the high frequency limit of the data (100 and 25 Hz for response and Fourier amplitude spectra, respectively).

B. Darragh; W. Silva; N. Gregor

2006-06-28

340

A new three-dimensional coordination polymer of Sr(II) based on dipicolinic acid, with different coordination environments for Sr(II).  

PubMed

A three-dimensional coordination polymer of Sr(II) based on dipicolinic acid (pydcH2) has been synthesized and characterized, namely poly[[diaquabis(?3-6-carboxypyridine-2-carboxylato)bis(?4-pyridine-2,6-dicarboxylato)tristrontium(II)] dihydrate], {[Sr3(C7H3NO4)2(C7H4NO4)2(H2O)2]·2H2O}n. The asymmetric unit consists of two unique Sr(II) centres (one of them situated on an inversion centre), two independent pydc(2-) ligands, and one coordinated and one uncoordinated water molecule. The two independent Sr(II) cations are surrounded by water and dipicolinate molecules in distorted square-antiprism and distorted tricapped trigonal prismatic geometries. The dipicolinate ligands adopt ?3- and ?4-bridging modes, linking the alkaline earth metal centres into a three-dimensional coordination framework. One dipicolinate ligand is doubly deprotonated, while the other is singly deprotonated. PMID:24898968

Soleimannejad, Janet; Derikvand, Zohreh; Koleiae, Farzaneh

2014-06-15

341

One-Dimensional Brownian Motion of Charged Nanoparticles along Microtubules: A Model System for Weak Binding Interactions  

PubMed Central

Abstract Various proteins are known to exhibit one-dimensional Brownian motion along charged rodlike polymers, such as microtubules (MTs), actin, and DNA. The electrostatic interaction between the proteins and the rodlike polymers appears to be crucial for one-dimensional Brownian motion, although the underlying mechanism has not been fully clarified. We examined the interactions of positively-charged nanoparticles composed of polyacrylamide gels with MTs. These hydrophilic nanoparticles bound to MTs and displayed one-dimensional Brownian motion in a charge-dependent manner, which indicates that nonspecific electrostatic interaction is sufficient for one-dimensional Brownian motion. The diffusion coefficient decreased exponentially with an increasing particle charge (with the exponent being 0.10 kBT per charge), whereas the duration of the interaction increased exponentially (exponent of 0.22 kBT per charge). These results can be explained semiquantitatively if one assumes that a particle repeats a cycle of binding to and movement along an MT until it finally dissociates from the MT. During the movement, a particle is still electrostatically constrained in the potential valley surrounding the MT. This entire process can be described by a three-state model analogous to the Michaelis-Menten scheme, in which the two parameters of the equilibrium constant between binding and movement, and the rate of dissociation from the MT, are derived as a function of the particle charge density. This study highlights the possibility that the weak binding interactions between proteins and rodlike polymers, e.g., MTs, are mediated by a similar, nonspecific charge-dependent mechanism. PMID:20409479

Minoura, Itsushi; Katayama, Eisaku; Sekimoto, Ken; Muto, Etsuko

2010-01-01

342

Probing ion coordination in polymer electrolytes with multinuclear NMR correlation spectroscopy  

Microsoft Academic Search

Solid polymer electrolytes (SPEs) are generally obtained by mixing an appropriate solvating polymer with alkali salt. Block copolymers based on poly(ethyleneoxide) (PEO) are suitable choices for SPEs because their polar ether moiety dissolves salts and their apolar component permits fine tuning of thermal and mechanical properties. However, the ionic properties of these materials depend greatly on the solvation state of

J.-P. Baltaze; P. Judeinstein

2010-01-01

343

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

344

Functional tetrametallic linker modules for coordination polymers and metal-organic frameworks.  

PubMed

The new biphenol-based tetranucleating ligand, 2,2',6,6'-tetrakis(N,N-bis(2-pyridylmethyl)aminomethyl)-4,4'-biphenolate, dbpbp2-, comprises two linearly disposed phenolato-hinged dinucleating heptadentate units, each of which offer one O and three N donors to a total of four metal ions. The ligand has been isolated as the zinc chloride complex [Zn4(dbpbp)Cl4]2+, and the ZnII ions have been completely or partially substituted by CuII, FeIII, CoII, and CoIII in metathesis reactions. Similarly, the chloride ligands of [Zn4(dbpbp)Cl4]2+ have been exchanged for solvent molecules (acetonitrile and/or water) and bridging carboxylate ligands. The resulting complexes have been characterized by single-crystal X-ray diffraction, ESI mass spectrometry (ESI-MS), cyclic voltammetry (CV), and EPR spectroscopy. The structures containing [M4(dbpbp)Cl4]2+ with M = ZnII or CuII exhibit 2-D polymeric honeycomb sheets in which intermolecular M...Cl interactions bridge between adjacent [M4(dbpbp)Cl4]2+ cations. Two mixed-metal tetrabenzoate complexes [M4(dbpbp)(O2CC6H5)4]2+/3+ have also been prepared, namely a stoichiometric CuII2ZnII2 complex and a nonstoichiometric FeIII/ZnII system. In the latter case, ESI-MS identifies FeZn3, Fe2Zn2, and Zn4 species, and X-ray crystallography suggests an average composition of Fe0.8Zn3.2. Preparation of a CoII4 complex by metathesis was considerably more difficult than preparation of [Cu4(dbpbp)Cl4]2+, requiring both a large excess of the cobalt source and the presence of auxiliary benzoate. In the presence of 2 equiv of benzoate per starting [Zn4(dbpbp)Cl4]2+ unit and excess CoII, dioxygen binds as peroxide at each end of the molecule to give the CoIII4 complex [Co4(dbpbp)(O2)2(O2CC6H5)2]4+. This latter complex, together with new tetra- and hexametallic benzenedicarboxylato- and benzenetricarboxylato-bridged complexes of dinuclear [Co2(O2)(bpbp)]3+ units (bpbp- = 2,6-bis(N,N-bis-(2-pyridylmethyl)aminomethyl)-4-tert-butyl-phenolate), is a module for potential construction of 1-D and 2-D coordination polymers/metal-organic frameworks (MOFs) capable of reversible O2 binding. PMID:17315867

Johansson, Frank B; Bond, Andrew D; McKenzie, Christine J

2007-03-19

345

One-dimensional overdriven detonations with branched-chain kinetics  

NASA Astrophysics Data System (ADS)

The dynamics of time-dependent, planar propagation of gaseous detonations is addressed on the basis of a three-step chemistry model that describes branched-chain processes. Relevant nondimensional parameters are the ratio of the heat release to the thermal enthalpy at the Neumann state, the nondimensional activation energies for the initiation and branching steps, the ratio of the branching time to the initiation time and the ratio of the branching time to the recombination time. The limit of strong overdrive is considered, in which pressure remains constant downstream from the leading shock in the first approximation, and the ratio of specific heats ? is taken to be near unity. A two-term expansion in the strong overdrive factor is introduced, and an integral equation is derived describing the nonlinear dynamics and exhibiting a bifurcation parameter, the reciprocal of the product of (?-1), the nondimensional heat release and the nondimensional branching activation energy, with an acoustic correction. A stability analysis shows that, depending on values of the parameters, either the mode of lowest frequency or a mode of higher frequency may be most unstable. Numerical integrations exhibit different conditions under which oscillations die, low-frequency oscillations prevail, high-frequency oscillations prevail, highly nonlinear oscillations persist, or detonation failure occurs. This type of parametric analysis is feasible because of the relative simplicity of the model, which still is more realistic than a one-step, Arrhenius chemical approximation. In particular, by addressing the limit of slow radical recombination compared with branching, explicit results are derived for the critical value of the bifurcation parameter, involving the ratio of the recombination time to the induction time. The results help to clarify the general nature of one-dimensional detonation instability and provide simplifications that can be employed in efficiently relating gaseous detonation behavior to the true underlying chemistry.

Sánchez, Antonio L.; Carretero, Manuel; Clavin, Paul; Williams, Forman A.

2001-03-01

346

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

347

One-dimensional quantum waveguide theory of Rashba electrons  

NASA Astrophysics Data System (ADS)

The ballistic spin transport in one-dimensional waveguides with the Rashba effect is studied. Due to the Rashba effect, there are two electron states with different wave vectors for the same energy. The wave functions of two Rashba electron states are derived, and it is found that their phase depend on the direction of the circuit and the spin directions of two states are perpendicular to the circuit, with the +?/2 and -?/2 angles, respectively. The boundary conditions of the wave functions and their derivatives at the intersection of circuits are given, which can be used to investigate the waveguide transport properties of Rashba spin electron in circuits of any shape and structure. The eigenstates of the closed circular and square loops are studied by using the transfer matrix method. The transfer matrix M(E ) of a circular arc is obtained by dividing the circular arc into N segments and multiplying the transfer matrix of each straight segment. The energies of eigenstates in the closed loop are obtained by solving the equation det[M(E )-I]=0. For the circular ring, the eigenenergies obtained with this method are in agreement with those obtained by solving the Schrödinger equation. For the square loop, the analytic formula of the eigenenergies is obtained first. The transport properties of the AB ring and AB square loop and double square loop are studied using the boundary conditions and the transfer matrix method. In the case of no magnetic field, the zero points of the reflection coefficients are just the energies of eigenstates in closed loops. In the case of magnetic field, the transmission and reflection coefficients all oscillate with the magnetic field; the oscillating period is ?m=hc/e, independent of the shape of the loop, and ?m is the magnetic flux through the loop. For the double loop the oscillating period is ?m=hc/2e, in agreement with the experimental result. At last, we compared our method with Koga's experiment.

Liu, Duan-Yang; Xia, Jian-Bai; Chang, Yia-Chung

2009-11-01

348

High-Frequency Characteristics of One-Dimensional Carbon Nanostructures  

NASA Astrophysics Data System (ADS)

The ever increasing demand for faster and more reliable chips depends largely on the performance of on-chip interconnects. Over ten years ago, copper became the preferred metal over aluminum as the on-chip interconnects material in the most advanced silicon chip technology. However, as copper interconnects scale down, its resistivity increases exponentially due to the degrading effect of surface scattering and grain-boundary scattering. Currently, the scaled-down copper interconnects suffer from reliability concerns due to electromigration in the sub-30 nm technology regime. In order to keep up with the International Technology Roadmap for Semiconductors (ITRS), copper must be replaced. Because of their superior properties, carbon-based nanostructures are the preferred choice to replace copper in next-generation integrated circuits. The principal objective of this work is to develop a methodology to investigate the high-frequency electrical conduction in one-dimensional carbon nanostructures, in particular, carbon nanofibers (CNFs) as a potential replacement for copper in next-generation on-chips interconnects. This work is divided into four parts. First, a high-frequency test structure with low transmission is designed and fabricated, allowing capacitances less than 1fF to be measured from 0.1 to 50 GHz. Second, S-parameters from 0.1 to 50 GHz are measured for the test structure and for the test structure connected by a CNF. Third, based on this data a frequency-independent parallel-RC network that models the CNF is proposed that matches the measured S-parameters. In this model the capacitance is the only fitting parameter. Finally, an analytical approach is developed that validates the frequency-independent RC -model, whose parameters are obtained directly from measurements without fitting. This simple RC-model takes into account the effect of both the contact impedance between the signal pads and the nanofiber, as well the impedance of the nanofiber.

Madriz Flores, Francisco R.

349

Integrable one-dimensional heavy fermion lattice model  

NASA Astrophysics Data System (ADS)

We consider a one-dimensional lattice gas of interacting electrons embedding a finite concentration of magnetic impurities. The host electrons propagate with nearest neighbor hopping t, constrained by the excluded multiple occupancy of the lattice sites, and interact with electrons on neighboring sites via spin exchange J and a charge interaction ( t- J model). The host is integrable at the supersymmetric point, J = 2 t, where charges and spin form a graded FFB superalgebra. Without destroying the integrability we introduce a finite concentration of mixed-valent impurities with two magnetic configurations of spin S and (S + {1}/{2}) , respectively, which hybridize with the conduction states of the host. We derive the Bethe ansatz equations diagonalizing the correlated host with impurities and discuss the ground-state properties as a function of magnetic field and the Kondo exchange coupling. While for an isolated impurity the ground state is magnetic of effective spin S, a finite concentration of impurities introduces an additional Dirac sea (the impurity band), which gives rise to a singlet ground state. The impurities are antiferromagnetically correlated and frustrated in zero-field. As a function of field first the narrow impurity band is spin polarized. The van Hove singularities of the spindashrapidity bands define critical fields at which the susceptibility diverges. The number of itinerant electrons and the concentration of impurities can be varied continuously, so that the Kondo problem, the supersymmetric t- J model and the antiferromagnetic Heisenberg chain are contained as special limits. The properties of the model are related to heavy fermion alloys and the Kondo lattice.

Schlottmann, P.

1998-08-01

350

Self-assembly of colloidal one-dimensional nanocrystals.  

PubMed

The ability of nanoscopic materials to self-organize into large-scale assembly structures that exhibit unique collective properties has opened up new and exciting opportunities in the field of nanotechnology. Although earlier work on nanoscale self-assembly has focused on colloidal spherical nanocrystals as building blocks, there has been significant interest in recent years in the self-assembly of colloidal nanocrystals having well-defined facets or anisotropic shapes. In this review, particular attention is drawn to anisotropic one-dimensional (1D) nanocrystals, notably nanorods and nanowires, which can be arranged into a multitude of higher-order assembly structures. Different strategies have been developed to realize self-assembly of colloidal 1D nanocrystals and these are highlighted in the first part of this review. Self-assembly can take place (1) on substrates through evaporation control, external field facilitation and template use; (2) at interfaces, such as the liquid-liquid and the gas-liquid interface; and (3) in solutions via chemical bonding, depletion attraction forces and linker-mediated interactions. The choice of a self-assembly approach is pivotal to achieving the desired assembly configuration with properties that can be exploited for functional device applications. In the subsequent sections, the various assembly structures that have been created through 1D nanocrystal self-assembly are presented. These organized structures are broadly categorized into non-close-packed and close-packed configurations, and are further classified based on the different types of 1D nanocrystal alignment (side-by-side and end-to-end), orientation (horizontal and vertical) and ordering (nematic and smectic), and depending on the dimensionality of the structure (2D and 3D). The conditions under which different types of arrangements are achieved are also discussed. PMID:24413386

Zhang, Shuang-Yuan; Regulacio, Michelle D; Han, Ming-Yong

2014-04-01

351

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

352

Stereo correspondence in one-dimensional Gabor stimuli.  

PubMed

Previous data [Prince, S.J.D., & Eagle, R.A., (1999). Size-disparity correlation in human binocular depth perception. Proceedings of the Royal Society of London B, 266, 1361-1365] have demonstrated that the upper disparity limit for stereopsis (DMax) is considerably smaller in filtered noise stereograms than in isolated Gabor patches of the same spatial frequency. This discrepancy is not currently understood. Here, the solution of the correspondence problem for bandpass stereograms was further examined. On each trial observers were presented with two one-dimensional Gabor stimuli containing disparities of equal magnitude but opposite sign. Subjects were required to indicate which interval contained the crossed disparity stimulus. It was found that matching behaviour changed as a function of Gabor envelope size. As a function of disparity magnitude, performance cycled between mostly correct and mostly incorrect at large envelope sizes but was always correct at small envelope sizes. At intermediate envelope sizes performance was cyclical at small disparities but always correct at large disparities. The critical envelope size at which performance changed from mostly correct to mostly incorrect at 270 degrees phase disparity was used as a measure of the matching performance as other parameters of the Gabor were varied. Both absolute and relative contrast were shown to influence the perceived sign of matches. Critical envelope size was also found to decrease as a function of spatial frequency, but more slowly than a phase-based limit would predict. These data cannot be predicted by current models of stereopsis, and can be used to constrain future models. PMID:10720662

Prince, S J; Eagle, R A

2000-01-01

353

Heterolayered, one-dimensional nanobuilding block mat batteries.  

PubMed

The rapidly approaching smart/wearable energy era necessitates advanced rechargeable power sources with reliable electrochemical properties and versatile form factors. Here, as a unique and promising energy storage system to address this issue, we demonstrate a new class of heterolayered, one-dimensional (1D) nanobuilding block mat (h-nanomat) battery based on unitized separator/electrode assembly (SEA) architecture. The unitized SEAs consist of wood cellulose nanofibril (CNF) separator membranes and metallic current collector-/polymeric binder-free electrodes comprising solely single-walled carbon nanotube (SWNT)-netted electrode active materials (LiFePO4 (cathode) and Li4Ti5O12 (anode) powders are chosen as model systems to explore the proof of concept for h-nanomat batteries). The nanoporous CNF separator plays a critical role in securing the tightly interlocked electrode-separator interface. The SWNTs in the SEAs exhibit multifunctional roles as electron conductive additives, binders, current collectors and also non-Faradaic active materials. This structural/physicochemical uniqueness of the SEAs allows significant improvements in the mass loading of electrode active materials, electron transport pathways, electrolyte accessibility and misalignment-proof of separator/electrode interface. As a result, the h-nanomat batteries, which are easily fabricated by stacking anode SEA and cathode SEA, provide unprecedented advances in the electrochemical performance, shape flexibility and safety tolerance far beyond those achievable with conventional battery technologies. We anticipate that the h-nanomat batteries will open 1D nanobuilding block-driven new architectural design/opportunity for development of next-generation energy storage systems. PMID:25226349

Choi, Keun-Ho; Cho, Sung-Ju; Chun, Sang-Jin; Yoo, Jong Tae; Lee, Chang Kee; Kim, Woong; Wu, Qinglin; Park, Sang-Bum; Choi, Don-Ha; Lee, Sun-Young; Lee, Sang-Young

2014-10-01

354

Quasi-One Dimensional Models for Glassy Dynamics  

E-print Network

We describe numerical simulations and analyses of a quasi-one-dimensional (Q1D) model of glassy dynamics. In this model, hard rods undergo Brownian dynamics through a series of narrow channels connected by $J$ intersections. We do not allow the rods to turn at the intersections, and thus there is a single, continuous route through the system. This Q1D model displays caging behavior, collective particle rearrangements, and rapid growth of the structural relaxation time, which are also found in supercooled liquids and glasses. The mean-square displacement $\\Sigma(t)$ for this Q1D model displays several dynamical regimes: 1) short-time diffusion $\\Sigma(t) \\sim t$, 2) a plateau in the mean-square displacement caused by caging behavior, 3) single-file diffusion characterized by anomalous scaling $\\Sigma(t) \\sim t^{0.5}$ at intermediate times, and 4) a crossover to long-time diffusion $\\Sigma(t) \\sim t$ for times $t$ that grow with the complexity of the circuit. We develop a general procedure for determining the structural relaxation time $t_D$, beyond which the system undergoes long-time diffusion, as a function of the packing fraction $\\phi$ and system topology. This procedure involves several steps: 1) define a set of distinct microstates in configuration space of the system, 2) construct a directed network of microstates and transitions between them, 3) identify minimal, closed loops in the network that give rise to structural relaxation, 4) determine the frequencies of `bottleneck' microstates that control the slow dynamics and time required to transition out of them, and 5) use the microstate frequencies and lifetimes to deduce $t_D(\\phi)$. We find that $t_D$ obeys power-law scaling, $t_D\\sim (\\phi^* - \\phi)^{-\\alpha}$, where both $\\phi^*$ (signaling complete kinetic arrest) and $\\alpha>0$ depend on the system topology.

Prasanta Pal; Jerzy Blawzdziewicz; Corey S. O'Hern

2014-01-06

355

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 \\taudependence 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

356

One dimensional scattering of a two body interacting system by an infinite wall  

E-print Network

The one-dimensional scattering of a two body interacting system by an infinite wall is studied in a quantum-mechanical framework. This problem contains some of the dynamical features present in the collision of atomic, molecular and nuclear systems. The scattering problem is solved exactly, for the case of a harmonic interaction between the fragments. The exact result is used to assess the validity of two different approximations to the scattering process. The adiabatic approximation, which considers that the relative co-ordinate is frozen during the scattering process, is found to be inadequate for this problem. The uncorrelated scattering approximation, which neglects the correlation between the fragments, gives results in accordance with the exact calculations when the scattering energy is high compared to the oscillator parameter.

A. M. Moro; J. A. Caballero; J. Gomez-Camacho

2010-10-24

357

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

358

Interpenetrating coordination polymers from Cu(I) or Ag(I) and flexible ligands: 2D polyrotaxanes and interpenetrating grids.  

PubMed

The reaction of [Cu(CH3CN)4]NO3 or AgNO3 with flexible ligands 1,4-bis(4-pyridylmethyl)-2,3,5,6-tetrafluorobenzene (bpf) or 4,4'-bis(4-pyridylmethyl)-2,2',3,3',5,5',6,6'-octafluorobiphenyl (bpfb) afforded two types of interpenetrating coordination polymers. The structures of [Cu2(bpf)3(NO3)2]n and [Ag2(bpf)3-(NO3)2]n are 2D polyrotaxane networks in which 1D polymeric chains are aligned in a grid. The structure of {[Cu(bpfb)2]NO3}n is a 2D grid polymer with two-fold parallel interpenetration. PMID:17441069

Kasai, Kayoko; Sato, Mariko

2006-09-18

359

Polymer complexes.. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes  

NASA Astrophysics Data System (ADS)

The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [( 11)+( 12)] in the paper and in mononuclear polymer complexes ( 1)-( 5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX 2 and KPtCl 4 in the presence of N-heterocyclic base consisting of polymer complexes ( 9)+( 10), and in monouclear compounds ( 6)-( 8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds ( 13)+( 14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

El-Sonbati, A. Z.; El-Bindary, A. A.; Diab, M. A.

2003-02-01

360

Five new Mn(II)/Co(II) coordination polymers constructed from flexible multicarboxylate ligands with varying magnetic properties  

SciTech Connect

Five new Mn(II)/Co(II) coordination polymers [Mn{sub 2}(Adi){sub 2}(DMA)]{sub n} (1), [Mn{sub 2}(Adi){sub 2}(DMF)]{sub n} (2), [Mn{sub 4}(Adi){sub 4}(DMF){sub 2}]{sub n} (3), [Co{sub 4}(Adi){sub 4}(DMF){sub 2}]{sub n} (4) and ([Co{sub 3}(Cit){sub 2}(H{sub 2}O){sub 3}]·(H{sub 2}O)){sub n} (5) [Adi=adipate anion, Cit=citrate anion, DMA=N,N?-dimethylacetamide and DMF=N,N?-dimethylformamide] have been successfully constructed from two flexible multicarboxylate ligands under solvothermal conditions. Complexes 1 and 2 exhibit 2-D network featured 1-D Mn{sup II} chain, 3 and 4 are 3-D frameworks containing different 1-D carboxylate–metal chain, while 5 shows a 3-D structure based on Co{sub 6} wheel clusters. Magnetic investigations indicate antiferromagnetic behaviors for 1–4 and weak ferromagnetic behavior for 5 because of distinct linkage modes of metal ions. - Graphical abstract: Five new Mn(II)/Co(II) coordination polymers display 2-D/3-D structures containing 1-D carboxylate–metal chains or wheel clusters. Magnetic analyses reveal that they show antiferromagnetic, canted antiferromagnetic and weak ferromagnetic behaviors, respectively. Highlights: ?Five new Mn(II)/Co(II) coordination polymers have been synthesized. ?A complex-based Co{sub 6} wheel cluster was obtained. ?The different magnetic properties of the complexes are discussed.

Liu, Sui-Jun; Zeng, Yong-Fei; Hu, Xin; Xue, Li; Han, Song-De; Jia, Ji-Min; Hu, Tong-Liang, E-mail: tlhu@nankai.edu.cn

2013-08-15

361

High energy eigenfunctions of one-dimensional Schrodinger operators with polynomial  

E-print Network

High energy eigenfunctions of one-dimensional Schr¨odinger operators with polynomial potentials A. Eremenko , A. Gabrielov and B. Shapiro May 25, 2007 Abstract For a class of one-dimensional Schr¨odinger

Gabrielov, Andrei

362

Quasi-One-Dimensional Modeling of Pulse Detonation Rocket Engines  

NASA Technical Reports Server (NTRS)

Pulsed detonation rocket engines (PDREs) have generated considerable research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred a great deal of interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the difficulties in comparing the available experimental measurements with numerical models. In a previous paper by the author, parametric studies of the performance of a single, straight-tube PDRE were reported. A 1-D, unsteady method of characteristics code, employing a constant-gamma assumption behind the detonation front, was developed for that study. Models of this type are computationally inexpensive, and are particularly useful for parametric performance comparisons. For example, a plot showing the specific impulse of various PDRE and steady-state rocket engine (SSRE) configurations as a function of blowdown pressure ratio. The performance curves clearly indicate that a straight-tube PDRE is superior in specific impulse to a SSRE with a sonic nozzle over the entire range of pressure ratios. Note, however, that a straight-tube PDRE in general does not compare favorably to a SSRE fitted with an optimized de Laval supersonic nozzle, particularly at the high pressure ratios typical for boost or in-space rocket applications. However, the calculations also show that if a dynamically optimized, supersonic de Laval nozzle could be could be fitted to a PDRE, then the specific impulse of the device would exceed that of a comparable SSRE. While such a nozzle is a considerable idealization, it is clear that nozzle design and optimization will play a critical role in whether the performance potential of PDREs can be effectively realized in practice. In order to study PDRE nozzle issues with greater accuracy, a quasi-one-dimensional, finite-rate chemistry CFD code has been developed by the author. Comparisons of the code with both the previous MOC model and experimental data from Stanford University are reported. The effect of constant-gamma and finite-rate chemistry assumptions on the flowfield and performance is examined. Parametric studies of the effect of nozzle throat size and expansion ratio, at various blowdown pressure ratios, are reported.

Morris, Christopher I.

2002-01-01

363

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

364

Extracting complexity waveforms from one-dimensional signals  

PubMed Central

Background Nonlinear methods provide a direct way of estimating complexity of one-dimensional sampled signals through calculation of Higuchi's fractal dimension (1

Kalauzi, Aleksandar; Bojic, Tijana; Rakic, Ljubisav

2009-01-01

365

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

366

Synthesis, structure, and characterization of a silver(I) coordination polymer with ?6-bridging 2,2?-bipyridyl-3,3?-dicarboxylate  

Microsoft Academic Search

A silver(I) coordination polymer, [Ag2(bpdc)]n (1) (H2bpdc = 2,2?-bipyridyl-3,3?-dicarboxylic acid), has been synthesized and characterized. Compound 1 exhibits a 2-D network containing 1-D channels. Each (bpdc) is an octadentate ?6-1igand coordinating with six Ag(I)'s in 1. This coordination of (bpdc) ligand is first observed here. Neighboring networks are arranged in a [ABAB···] pattern to form 3-D supramolecular architecture by ?···?

Xiao-Li Chen; Yue-Juan Yao; Huai-Ming Hu; Shuan-Hu Chen; Feng Fu

2009-01-01

367

A Yb(III)-Zn(II) heterometallic coordination polymer with interesting three-fold 1D pseudo-nanotube architectures  

NASA Astrophysics Data System (ADS)

A heterometallic coordination polymer formulated as [YbZn(btc)(OH)2(H2O)]·H2O (1), where H3btc = 1,3,5-benzenetricarboxylic acid has been synthesized under hydrothermal condition. Single crystal analysis reveals that complex 1 presents a three-dimensional (3D) structure containing three-fold 1D pseudo-nanotube architectures. The complex has also been characterized by IR, PXRD, TG and elemental analysis. Moreover, solid-state photoluminescence property of the complex has also been investigated at room temperature.

Xu, Bo; Yuan, Senwen; Zhang, Xiutao; Li, Cuncheng

2014-06-01

368

Hydrothermal synthesis and characterization of a zigzag neodymium-2,2?-bipyridine-3,3?-dicarboxylate-isonicotinate coordination polymer  

Microsoft Academic Search

A new neodymium(III) coordination polymer, {[Nd(bpdc)(iso)(H2O)2] ? (H2O)2.25}n (1), was synthesized by treating neodymium oxide with 2,2?-bipyridine-3,3?-dicarboxylic acid (H2bpdc), and isonicotinic acid (Hiso) under hydrothermal conditions. Single-crystal X-ray diffraction shows that 1 is a 1-D zigzag chain and extends to 2-D network structure through ?–? interactions and hydrogen bonds. Thermogravimetric analysis of 1 displays a considerable thermal stability. The variable-temperature

Ming Hu; Jingya Yao; Haiquan Su

2010-01-01

369

A novel double-helical-chain coordination polymer constructed from 2,2 ?-biphenyldicarboxylate-linked binuclear-copper motif  

Microsoft Academic Search

The first 1-D double-helical-chain coordination polymer, [(H2O)Cu(BPDC)] (2,2?-biphenyldicarboxylate), based upon the binuclear square pyramidal copper(II)-pair motifs has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction technique. [(H2O)Cu(BPDC)] crystallized in orthorhombic crystal system, space group Cmca with unit cell dimensions a=21.073(6) Å, b=7.118(2) Å and c=17.670(5) Å, Z=8.

Jack Y. Lu; Vaughn Schauss

2003-01-01

370

Synthesis, structure, and photoluminescence of a series of lanthanide coordination polymers constructed from nitrogen containing organic ligands  

Microsoft Academic Search

We have synthesized four coordination polymers with two different nitrogen containing organic ligands and different lanthanide metal ions, under hydrothermal condition. [{Ln2(bpdc)3(H2O)2}]n (Ln = Dy (1), Sm (2)) (bpdc = 2,2-bipyridine-3,3-dicarboxylic acid) are isostructural, with 2-D supramolecular layer structure composed from 1-D chains. Like 1 and 2, [{Ln(pzda)2(H2O)2} · 4H2O]n (Ln = Dy (3), Nd (4)) (pzda = pyrazine-2,6-dicarboxylic acid)

Xinxin Xu; Xiaoxia Liu; Ting Sun; Xia Zhang; Enbo Wang

2009-01-01

371

A novel silver(?) coordination polymer based on mixed ligands bpp and 2,2?-bipyridine-4,4?-dicarboxylate  

Microsoft Academic Search

A novel coordination polymer based on silver(?) and mixed ligands {[Ag2(bpdc)(bpp)(H2O)]·2H2O}n (1) (H2bpdc=2,2?-bipyridyl-4,4?-dicarboxylic acid, bpp=1,3-bis(4-pyridyl)propane), has been prepared by hydrothermal method. Compound 1 has a 2D polymeric structure extended with subunits tetranuclear silver with Schläfli symbol {3^12;4^9;5^6;6^9}{3^18;4^22;5^5}. Compound 1 represents an Ag-containing polymeric compound possessing room-temperature luminescence.

Cui-Juan Wang; Yao-Yu Wang; Hong Wang; Guo-Ping Yang; Gui-Lin Wen; Mei Zhang; Qi-Zhen Shi

2008-01-01

372

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

373

1D coordination polymers of Cu(II) and Cu(II) dimers with a dicyanomethanide ligand  

Microsoft Academic Search

Several new 1D coordination polymers have been synthesised using the anionic ligand carbamoyldicyanomethanide, C(CN)2(CONH2)? (cdm). The polymeric complexes [Cu(cdm)2(py)2]·2MeOH (1), [Cu(cdm)2(4-Etpy)2]·2MeOH (2), [Cu(cdm)2(3,5-Me2pzH)2]·2MeOH (3) and [Cu(cdm)2(3-HOCH2py)2]·2MeOH (4) (py=pyridine; 3,5-Me2pzH=3,5-dimethylpyrazole) contain Cu(II) atoms bridged by ?2-(N,N?) cdm ligands between equatorial and axial coordination sites. The use of monodentate co-ligands brings about polymeric products, in contrast to the use previously of chelating

David R. Turner; Stuart R. Batten

2010-01-01

374

Structural and spectral properties of a zinc(II) coordination polymer: A combined experimental and theoretical study  

NASA Astrophysics Data System (ADS)

A novel 1D zinc(II) coordination polymer [Zn(bbbm)Cl2]n (where bbbm = 1,4-bis(N-benzimidazolyl)butane) was synthetized by ZnCl2 and bbbm ligand under hydrothermal conditions, and its structural and spectral properties were studied by both experimental and theoretical techniques. The center zinc(II) ion displays four-coordinated in a tetrahedral geometry by two chloride anions and two N atoms of distinct bbbm ligands. Adjacent chains are further connected into a 2D layer structure through ?-? stacking interactions. Vibrational frequencies of [Zn(bbbm)Cl2]n have been calculated using DFT/B3LYP/TZVP method, and well reproduced IR data. Furthermore, the vertical excitation energies from time-dependent DFT calculation confirmed that the fluorescent peaks at 385 nm and 450 nm could respectively be assigned to the ? ? ?* transition within the bbbm ligands and ? ? n transition from chloride anion to bbbm ligand.

Hao, Jin-Ming; Li, Guang-Yue; Li, Yue-Hua; Cui, Guang Hua

2014-10-01

375

A (3,4)-connected two-dimensional copper coordination polymer with a 2D ? 3D polycatenation network  

NASA Astrophysics Data System (ADS)

The reaction of 1,3,5-tri(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene (ttmb) with CuCl 2 yields a coordination polymer [Cu 3(ttmb) 2(H 2O) 6Cl 6] n·3 nH 2O ( 1). The flexible ligand ttmb shows the cis,cis,cis-conformation and a tri-monodentate coordination mode in 1. Each ttmb links three Cu(II) atoms to form an undulated (3,4)-connected two-dimensional network. Each undulated two-dimensional network polycatenates other two identical networks, thus giving a rare (2D ? 3D) parallel polycatenation network in 1. The thermal stability of compound 1 was studied.

Wang, Hong-Liang; Feng, Yun-Fei; Liang, Na; Li, Bao-Long; Li, Hai-Yan

2010-02-01

376

Csbnd H⋯Pd interactions: One dimensional heteropolynuclear complexes  

NASA Astrophysics Data System (ADS)

Three cyanide complexes, [Cu(hepH)2Pd(?-CN)2(CN)2]n (1), [Zn(hepH)2Pd(?-CN)2(CN)2]n (2) and [Cd(hepH)2Pd(?-CN)2(CN)2]n (3) (2-pyridineethanol abbreviated to hepH), have been synthesized and characterized by various techniques (elemental analysis, FT-IR and Raman spectroscopy, thermal analysis and single crystal X-ray diffraction). FT-IR spectroscopy pointed out the existence of terminal and bridged cyanide ligands in the complexes. The crystallographic analyses reveal that complexes 1 and 2 crystallize in the triclinic system, space group P - 1 and complex 3 crystallizes in the monoclinic system, space group P21/n. The palladium atom is coordinated with cyanide-carbon atoms in a square-planar arrangement and the metal(II) atoms are six-coordinated with two cyanide nitrogen, two hepH nitrogen and two hepH oxygen atoms, in a distorted octahedral arrangement. In all the complexes adjacent chains are connected by Csbnd H⋯Pd, ?⋯? and Osbnd H⋯N hydrogen bonding interactions to form two- and three-dimensional networks. When it comes to thermal analysis, the complexes followed usual decomposition mechanism in which neutral ligands (hepH) are released first, and then cyanide ligands are decomposed. The final decomposition products are found to be the corresponding metal oxides.

Say?n, Elvan; Kürkçüo?lu, Güne? Süheyla; Ye?ilel, Okan Zafer; Hökelek, Tuncer

2014-11-01

377

CH?Pd interactions: one dimensional heteropolynuclear complexes.  

PubMed

Three cyanide complexes, [Cu(hepH)2Pd(?-CN)2(CN)2]n (1), [Zn(hepH)2Pd(?-CN)2(CN)2]n (2) and [Cd(hepH)2Pd(?-CN)2(CN)2]n (3) (2-pyridineethanol abbreviated to hepH), have been synthesized and characterized by various techniques (elemental analysis, FT-IR and Raman spectroscopy, thermal analysis and single crystal X-ray diffraction). FT-IR spectroscopy pointed out the existence of terminal and bridged cyanide ligands in the complexes. The crystallographic analyses reveal that complexes 1 and 2 crystallize in the triclinic system, space group P-1 and complex 3 crystallizes in the monoclinic system, space group P2?/n. The palladium atom is coordinated with cyanide-carbon atoms in a square-planar arrangement and the metal(II) atoms are six-coordinated with two cyanide nitrogen, two hepH nitrogen and two hepH oxygen atoms, in a distorted octahedral arrangement. In all the complexes adjacent chains are connected by CH?Pd, ??? and OH?N hydrogen bonding interactions to form two- and three-dimensional networks. When it comes to thermal analysis, the complexes followed usual decomposition mechanism in which neutral ligands (hepH) are released first, and then cyanide ligands are decomposed. The final decomposition products are found to be the corresponding metal oxides. PMID:24975519

Say?n, Elvan; Kürkçüo?lu, Güne? Süheyla; Ye?ilel, Okan Zafer; Hökelek, Tuncer

2014-11-11

378

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

379

One-dimensional Bose gas on an atom chip  

NASA Astrophysics Data System (ADS)

We describe experiments investigating the (coherence) properties of a finite-temperature one-dimensional (1D) Bose gas with repulsive interactions. The confining magnetic field is generated with a micro-electronic circuit. This microtrap for atoms or `atom chip' is particularly suited to generate a tight waveguide for atoms close to the chip surface. In contrast to the usual case of Bose-Einstein condensation in 3D, in 1D the system is not characterized by long-range phase coherence. Further interest in the 1D Bose gas stems from the fact that it forms the textbook example for the many-body quantum-mechanical systems that can be exactly solved using the Bethe Ansatz. Moreover, using a method developed by Yang and Yang, exact expressions for the thermodynamics of this system can be given. We summarize the theoretical background that is relevant to describe the (nearly) 1D gas in our experiments. The design and construction of our microtrap is described in some detail. We discuss the technique of Bose-gas focusing, in particular how it applies to our 1D system, and demonstrate that it can be used to probe the momentum distribution of the 1D gas. Finally, we perform a direct comparison of the measured in situ density distribution to the predictions of a model based on the exact Yang-Yang thermodynamics and find very good agreement. Gaz de Bose unidimensionnel sur une puce atomique. Nous décrivons des expériences permettant d'étudier les propriétés (en particulier la cohérence) d'un gaz unidimensionel (1D) de Bose à température finie avec des interactions répulsives. Le champ magnétique confinant est créé par un circuit micro-électronique. Ce micro-piège à atomes ou "puce atomique" est particulièrement adapté pour générer un guide très confinant pour les atomes près de la surface de la puce. Contrairement au cas habituel de la condensation de Bose-Einstein en 3D, le système uni-dimensionnel n'est pas caractérisé par une cohérence de phase à longue portée. Un intérêt supplémentaire du gaz uni-dimensionnel de Bose est qu'il offre un cas d'école de systèmes quantiques à plusieurs corps pouvant être résolus exactement en utilisant l'ansatz de Bethe. De plus, grâce à une méthode développée par Yang et Yang, on peut obtenir les expressions exactes de la thermodynamique de ces systèmes. Nous rappelons le cadre théorique permettant de décrire le gaz quasi-unidimensionel dans nos expériences. La conception et la construction de notre micro-piège sont décrits en détails. Nous discutons la technique de focalisation du gaz de Bose, et en particulier son application à notre système unidimensionel, et nous montrons qu'elle peut être utilisée pour déterminer la distribution d'impulsions du gaz unidimensionel. Finalement, nous comparons directement la distribution de densité mesurée in situ, aux prédictions d'un modèle basé sur la thermodynamique exacte de Yang et Yang et nous trouvons un très bon accord.

van Amerongen, A. H.

380

Syntheses, crystal structure and properties of two novel coordination polymers with the flexible tetrazole-1-acetic acid (Htza)  

SciTech Connect

Two new coordination polymers, [Ag(tza)]{sub {infinity}} (1) (Htza=tetrazole-1-acetic acid) and [Cu(tza){sub 2}]{sub {infinity}} (2) have been prepared at room temperature and characterized by X-ray crystallography, IR, UV-vis, fluorescence spectra and magnetism analysis. Compound 1 exhibits extended helical chains through bridging ligand tza. The Ag{center_dot}{center_dot}{center_dot}Ag interactions between the adjacent chains form a 3-D framework featuring the extended tza-connected Ag chains that obviously affect the photoluminescent property. Compound 2 features undulated layered structure with hourglass-shaped [Cu{sub 4}(tza){sub 4}] as subunits with the weak ferromagnetic interactions between Cu(II) ions, which are further stabilized by inter-lamellar C-H{center_dot}{center_dot}{center_dot}O hydrogen bonds in the resulting 3-D supramolecular framework. - Graphical abstract: Two novel coordination polymers, [Ag(tza)]{sub {infinity}} (1) and [Cu(tza){sub 2{infinity}} (2) have been prepared and characterized. Compound 1 features extended double-stranded helical chains. Compound 2 features undulated layered structure with hourglass-shaped [Cu{sub 4}(tza){sub 4}] as subunits with the weak ferromagnetic interactions between Cu(II) ions.

Dong Wenwen; Zhao Jun [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Xu Li [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)], E-mail: xli@fjirsm.ac.cn

2008-05-15

381

3-D coordination polymers based on the tetrathiafulvalenetetracarboxylate (TTF-TC) derivative: synthesis, characterization, and oxidation issues.  

PubMed

The reactivity of the redox-active tetracarboxylic acid derived from the tetrathiafulvalene (TTF-TC)H(4) with alkaline cations (K, Rb, Cs) is reported. The exploration of various experimental parameters (temperature, pH) led to the formation of four crystalline three-dimensional coordination polymers formulated M(2)(TTF-TC)H(2) (M = K, Rb, Cs), denoted MIL-132(K), MIL-133(isostructural K, Rb), and MIL-134(Cs). Thermogravimetric analysis and thermodiffraction show that all of the solids are thermally stable up to 150-200 degrees C in the air. In order to exploit the possibility of oxidation of the organic linker in TTF-based compounds, they were employed as positive electrodes in a classical lithium cell. A highly reversible cyclability was achieved at high current density (10 C) with a reasonable performance (approximately 50 mAh g(-1)). Finally, combined electro-(sub)hydrothermal synthesis was used to prepare a fifth 3-D coordination polymer formulated K(TTF-TC)H(2) (denoted MIL-135(K)), this time not based on the neutral TTF-TC linker but its radical, oxidized form TTF-TC(+*). This solid is less thermally stable than its neutral counterparts but exhibits a semiconducting behavior, with a conductivity at room temperature of about 1 mS cm(-1). PMID:20597467

Nguyen, Thi Le Anh; Demir-Cakan, Rezan; Devic, Thomas; Morcrette, Mathieu; Ahnfeldt, Tim; Auban-Senzier, Pascale; Stock, Norbert; Goncalves, Anne-Marie; Filinchuk, Yaroslav; Tarascon, Jean-Marie; Férey, Gérard

2010-08-01

382

Influence of photoinduced electron transfer on lanthanide-based coordination polymer luminescence: a comparison between two pseudoisoreticular molecular networks.  

PubMed

The luminescent properties of two families of heteronuclear lanthanide-containing coordination polymers are compared. These families have general chemical formulas [Ln2-2xLn'2x(ip)3(H2O)9·6H2O]? and [Ln2-2xLn'2x(aip)2(H2O)10·(aip)·4H2O]? where H2ip and H2aip stand for isophthalic acid and 5-amino-isophthalic acid, respectively, and where Ln and Ln' are one of the lanthanide ions between Sm(3+) and Dy(3+). Heteronuclear compounds that belong to each family are isostructural to the already reported homonuclear compounds [Gd2(ip)3(H2O)9·6H2O]? and [Eu2(aip)2(H2O)10·(aip)·4H2O]?, respectively. These two crystal structures are very similar. However, despite similar chemical formulas, similar crystal structures, and similar hydration rates, these two families of compounds present very different luminescent properties that have thus been deeply investigated. This study demonstrates that these different optical behaviors can be attributed to the presence of a PET (photoinduced electron transfer) mechanism that is only present in the amino-isophthalate-containing coordination polymers. PMID:24400864

Freslon, Stéphane; Luo, Yun; Calvez, Guillaume; Daiguebonne, Carole; Guillou, Olivier; Bernot, Kevin; Michel, Vincent; Fan, Xiao

2014-01-21

383

Catenation control in the two-dimensional coordination polymers based on tritopic carboxylate linkers and azamacrocyclic nickel(II) complexes.  

PubMed

Four new coordination polymer frameworks, namely [(NiL(1))(3)(BTB)(2)]·6H(2)O, [(NiL(2))(3)(BTB)(2)]·6H(2)O, [(NiL(3))(3)(BTB)(2)]·6H(2)O and [(NiL(2))(3)(BTC)(2)]·10.25H(2)O (L(1) = 1,4,8,11-tetraazacyclotetradecane, L(2) = 3-methyl-1,3,5,8,12-pentaazacyclotetradecane, L(3) = 3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane, BTC(3-) = benzene-1,3,5-tricarboxylate, BTB(3-) = 4,4',4''-benzene-1,3,5-triyl-tribenzoate) were prepared in water-N,N-dimethylformamide solutions. The molecular and crystal structures of these compounds are compared to the related coordination polymers formed by nickel(II) macrocyclic cations to examine the effect of carboxylate linker size on the framework architecture. Luminescent properties of the complexes based on the BTB(3-) bridging ligand are also discussed. PMID:22266979

Lampeka, Yaroslaw D; Tsymbal, Liudmyla V; Barna, Andrij V; Shu?ga, Yulija L; Shova, Sergiu; Arion, Vladimir B

2012-04-14

384

Soft coordination supramolecular polymers: novel materials for dual electro-Yawei Liang,{a  

E-print Network

to the dynamic nature of coordinating bonds.8,11 In the past decade, various SCSPs of transition and rare earth metals with judicious ligands have been achieved.12,13 It is expected that these metal-containing novel

Huang, Jianbin

385

Semiclassical investigation of the revival phenomena in a one-dimensional system  

NASA Astrophysics Data System (ADS)

In a quantum revival, a localized wave packet re-forms or 'revives' into a compact reincarnation of itself long after it has spread in an unruly fashion over a region restricted only by the potential energy. This is a purely quantum phenomenon, which has no classical analog. Quantum revival and Anderson localization are members of a small class of subtle interference effects resulting in a quantum distribution radically different from the classical after long time evolution under classically nonlinear evolution. However, it is not clear that semiclassical methods, which start with the classical density and add interference effects, are in fact capable of capturing the revival phenomenon. Here we investigate two different one-dimensional systems, the infinite square well and Morse potential. In both the cases, after a long time the underlying classical manifolds are spread rather uniformly over phase space and are correspondingly spread in coordinate space, yet the semiclassical amplitudes are able to destructively interfere over most of coordinate space and constructively interfere in a small region, correctly reproducing a quantum revival. Further implications of this ability are discussed.

Wang, Zhe-xian; Heller, Eric J.

2009-07-01

386

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

387

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

388

Electrical conductivity and luminescence in coordination polymers based on copper(I)-halides and sulfur-pyrimidine ligands.  

PubMed

The solvothermal reactions between pyrimidinedisulfide (pym(2)S(2)) and CuI or CuBr(2) in CH(2)Cl(2):CH(3)CN lead to the formation of [Cu(11)I(7)(pymS)(4)](n) (pymSH = pyrimidine-2(1H)-thione) (1) and the dimer [Cu(II)(?-Br)(Br)L](2) (L = 2-(pyrimidin-2-ylamino)-1,3-thiazole-4-carbaldehyde) (2). In the later reaction, there is an in situ S-S, S-C(sp(2)), and C(sp(2))-N multiple bond cleavage of the pyrimidinedisulfide resulting in the formation of 2-(pyrimidin-2-ylamino)-1,3-thiazole-4-carbaldehyde. Interestingly, similar reactions carried out just with a change in the solvent (H(2)O:CH(3)CN instead of CH(2)Cl(2):CH(3)CN) give rise to the formation of coordination polymers with rather different architectures. Thus, the reaction between pym(2)S(2) and CuI leads to the formation of [Cu(3)I(pymS)(2)](n) (3) and [CuI(pym(2)S(3))] (pym(2)S(3) = pyrimidiltrisulfide) (4), while [Cu(3)Br(pymS)(2)](n) (5) is isolated in the reaction with CuBr(2). Finally, the solvothermal reactions between CuI and pyrimidine-2-thione (pymSH) in CH(2)Cl(2):CH(3)CN at different ratios, 1:1 or 2:1, give the polymers [Cu(2)I(2)(pymSH)(2)](n) (6) and [Cu(2)I(2)(pymSH)](n) (7), respectively. The structure of the new compounds has been determined by X-ray diffraction. The studies of the physical properties of the novel coordination polymers reveal that compounds 3 and 5 present excellent electrical conductivity values at room temperature, while compounds 1, 3, and 5-7 show luminescent strong red emission at room temperature. PMID:22148743

Gallego, Almudena; Castillo, Oscar; Gómez-García, Carlos J; Zamora, Félix; Delgado, Salome

2012-01-01

389

Hydrothermal synthesis and characterization of a copper(I) halide coordination polymer with isonicotinic acid (IN) ligand as a template possessing three-dimensional supramolecular network structure  

Microsoft Academic Search

The title compound [CuBr(IN)]n1 was hydrothermally synthesized from a simple reaction of CuBr2–IN–KBr–NaOH–H2O. X-ray analysis revealed that it is a new example containing extended one-dimensional staircase chain in copper(I) halide family. Its structure can be better described as a three-dimensional supramolecular network assembled via a combination of coordinate–covalent bonds and intermolecular hydrogen bonds. Moreover, compound 1 was characterized by elemental

Jie-Hui Yu; Ji-Qing Xu; Ling Ye; Hong Ding; Wei-Jie Jing; Tie-Gang Wang; Jia-Ning Xu; Hong-Bin Jia; Zhong-Cheng Mu; Guang-Di Yang

2002-01-01

390

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

391

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

392

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

SciTech Connect

The new 1D coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n} (1), where Piv=OOCBu{sup t-}, was synthesized in high yield (>95%) by the reaction of thulium acetate with pivalic acid in air at 100 Degree-Sign S. 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 Horizontal-Ellipsis +50 Degree-Sign S 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. - Graphical Abstract: Novel 1D coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n} was synthesized and studied by X-ray diffraction. The magnetic, luminescence properties, the thermal behavior and the volatility for the compound {l_brace}Tm(Piv){sub 3{r_brace}n} were investigated. Black-Small-Square Highlights: Black-Right-Pointing-Pointer We synthesized the coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n}. Black-Right-Pointing-Pointer Tm atoms in polymer have the coordination number 6. Black-Right-Pointing-Pointer Polymer exhibits blue-color emission at room temperature. Black-Right-Pointing-Pointer Polymer shows high thermal stability and volatility. Black-Right-Pointing-Pointer Polymer has no phase transitions in the range of -50 Horizontal-Ellipsis +50 Degree-Sign S.

Fomina, Irina, E-mail: fomina@igic.ras.ru [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, GSP-1 (Russian Federation); Dobrokhotova, Zhanna; Aleksandrov, Grygory [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, GSP-1 (Russian Federation); Emelina, Anna; Bykov, Mikhail [Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, GSP-1 (Russian Federation); Malkerova, Irina [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, GSP-1 (Russian Federation); Bogomyakov, Artem [International Tomography Center, Siberian Branch of the Russian Academy of Sciences, Institutskaya Str. 3a, 630090 Novosibirsk (Russian Federation); Puntus, Lada [Kotel'nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Mokhovaya Str. 11-7, 125009 Moscow (Russian Federation); Novotortsev, Vladimir; Eremenko, Igor [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, GSP-1 (Russian Federation)

2012-01-15

393

Template-assisted electrodeposition of one-dimensional nanostructures for sensing and solar energy applications  

NASA Astrophysics Data System (ADS)

One-dimensional nanowires and nanotubes offer unique properties that cannot be achieved with bulk materials. High surface area, strain relaxation, quantum confinement, and orthogonal light absorption and charge separation are examples. In this work, conducting polymer nanowires were synthesized by template-assisted electrodeposition. The dimensions of the nanowires could be easily controlled, and arrays or individual nanowires could be obtained. The conducting polymers synthesized were polypyrrole and poly(3,4-ethylendioxythiophene), as well as palladium-polymer and platinum-polymer composites. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) / energy-dispersive X-ray spectroscopy (EDS) were employed for structural characterization. Integration of the nanowires onto test structures was carried through electrofluidic assembly. Once assembled, the electrical properties of individual nanowires were investigated and studied for sensing of various gases. Template-assisted electrodeposition was also employed to synthesize cadmium selenide (CdSe) and copper indium diselenide (CuInSe2) nanowires. The crystal structure and crystallite domain size of the CdSe nanowires was controlled by either direct electrodeposition from an electrolyte that contained both elements or by topochemical cation exchange starting from crystalline t-Se nanowires. This was confirmed by TEM, X-ray Diffraction (XRD), and electron diffraction. CdSe nanowire photoanodes were used to study the effects of crystallite domain size on the photoelectrochemical properties. CuInSe2 nanowires were characterized by SEM, TEM/EDS, XRD, inductively coupled plasma mass spectrometry, Mott-Schottky analysis, and single wire electrical measurements. It was demonstrated that single phase p- and n-type CuInSe2 nanowires could be fabricated by this method. Since micro and nanowire arrays coupled to inexpensive catalysts are promising materials for unassisted-overall water splitting, the viability of membrane-based electrolytic cells was investigated. The challenge is to find conditions under which the cell can operate at solar flux (25 mA/cm 2) and near neutral pH without significant series resistance. Potential losses (DeltaE = iR + Em + EpH + Ecathode + Eanode) were analyzed with anion exchanger membranes and different buffers. It was discovered that monoprotic buffers gave minimal transmembrane pH gradients because of fast permeation of the membrane by the neutral acid. With these membrane/buffer combinations, it should be possible to separate the products of photoelectrolysis with low series resistance over a broad range of operating pH.

Hernandez-Pagan, Emil A.

394

Fluorescence enhancement by microphase separation-induced chain extension coordination polymers: phenomenon and analysis  

E-print Network

on fluorescent biomedical materials,1­3 developing new types of fluorescent assays whose sensitivity is high,7­9 However, both methods still require the concentration of the fluorescent species to be high enough. In practical biomedical applications, the concentration of fluorescent coordination complexes should

Huang, Jianbin

395

A new hetero-bimetallic coordination polymer, cesium, and sodium complex of styphnate trihydrate [CsNa(TNR)(H 2 O) 3 ] n  

Microsoft Academic Search

A new hetero-bimetallic coordination polymer, cesium, and sodium complex of styphnate trihydrate [CsNa(TNR)(H2O)3]\\u000a n\\u000a (TNR: 2,4,6-trinitroresorcinol dianion, the dianion of styphnic acid) was synthesized. The title complex was characterized\\u000a by X-ray single crystal diffraction, element analysis, FT-IR, DSC, TG-DTG studies. In the title polymer molecule, the cesium\\u000a cation is coordinated by 13 oxygen atoms: three originated from the water molecule

Jun-Wei Liu; Jian-Guo Zhang; Tong-Lai Zhang; Hong Zheng; Li Yang; Kai-Bei Yu

2009-01-01

396

One-dimensional transient analysis of volumetric heating for laser drilling  

SciTech Connect

Generally laser energy is considered to interact only with the substrate surface, as in metals, where the laser beam does not propagate into the substrate beyond a very small absorption depth. There are, however, many instances, particularly for ceramics and polymers, where the laser beam can penetrate into the substrate to substantial depths depending on the laser wavelength and laser-material interaction characteristics. Specifically there are polymeric dielectrics used as multilayer electronic substrates in which a laser beam of wavelength 9.3 {mu}m can penetrate into the substrate. The laser energy interacts at the substrate surface as well as inside the substrate. This particular aspect of laser-material interactions is important in laser drilling of blind microvias in polymeric multilayer electronic substrates. A one-dimensional transient heat conduction model including vaporization parameters is constructed to analyze this behavior. The absorption coefficient of the dielectric is also considered in this model and the problem is solved analytically. The microvia drilling speed, temperature distribution in the dielectric, and the thickness of the residue along the microvia walls and at the bottom of the microvia are studied for different laser irradiation conditions. An overheated metastable state of material is found to exist inside the workpiece. The overheating parameters are calculated for various laser drilling parameters and are used to predict the onset of thermal damage and to minimize the residue.

Zhang Chong; Salama, Islam A.; Quick, Nathaniel R.; Kar, Aravinda [Department of Mechanical, Materials and Aerospace Engineering, College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL), University of Central Florida, Orlando, Florida 32816-2700 (United States); Intel Corporation-Assembly and Technology Development, 5000 W. Chandler Boulevard, CH5-159, Chandler, Arizona 85226-3699 (United States); AppliCote Associates, LLC, 1445 Dolgner Place, Suite 23, Sanford, Florida 32771 (United States); College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL), University of Central Florida, Orlando, Florida 32816-2700 (United States)

2006-06-01

397

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

398

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

399

Syntheses, crystal structure and properties of two novel coordination polymers with the flexible tetrazole-1-acetic acid (Htza)  

NASA Astrophysics Data System (ADS)

Two new coordination polymers, [Ag(tza)] ? ( 1) (Htza=tetrazole-1-acetic acid) and [Cu(tza) 2] ? ( 2) have been prepared at room temperature and characterized by X-ray crystallography, IR, UV-vis, fluorescence spectra and magnetism analysis. Compound 1 exhibits extended helical chains through bridging ligand tza. The Ag rad rad rad Ag interactions between the adjacent chains form a 3-D framework featuring the extended tza-connected Ag chains that obviously affect the photoluminescent property. Compound 2 features undulated layered structure with hourglass-shaped [Cu 4(tza) 4] as subunits with the weak ferromagnetic interactions between Cu(II) ions, which are further stabilized by inter-lamellar C sbnd H rad rad rad O hydrogen bonds in the resulting 3-D supramolecular framework.

Dong, Wen-Wen; Zhao, Jun; Xu, Li

2008-05-01

400

Three distinct cadmium coordination polymers with a multidentate tripyridyl-substituted triazole tecton regulated by halide anions  

NASA Astrophysics Data System (ADS)

Three distinct Cd(II) coordination polymers [Cd3(L434)2Cl6]n (1), [Cd(L434)2Br2]n (2), and [Cd2(L434)2I4(H2O)2]n (3) have been designed and synthesized with a versatile building block 3,5-bis(4-pyridyl)-4-(3-pyridyl)-1,2,4-triazole (L434) by altering the Cd(II) halides of reaction systems. Single crystal X-ray diffraction reveals that 1-3 display different zigzag, box-like, and ladder-like 1D polymeric motifs, respectively. Moreover, aromatic stacking interactions are observed in all these structures to extend and/or stabilize the supramolecular lattices. Their thermal stabilities and fluorescent properties have also been explored. Significantly, the regular variation in structural patterns and photoluminescence properties of 1-3 can be properly ascribed to the diversification of halide anions.

Chen, Jing; Wu, Na; Li, Cheng-Peng

2013-11-01

401

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

NASA Astrophysics Data System (ADS)

Two new coordination polymers, namely, [Co(?-nip)(?-bpe)]n (1) and [Zn(?-nip)(?-bpe)]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 CO2/CH4 adsorption and separation were performed. Complex 1 consists of two dimensional (2D) (4,4) grid networks with the point symbol of 44.62. Complex 2 exhibits a 3-fold interpenetrating 3D framework with 65.8-dmp topology. Thermal properties of the complexes showed that both complexes were stable over 320 °C. Simulation studies demonstrated that complex 2 can separate CO2 from CH4 at low pressures at 273 K.

Ar?c?, Mürsel; Ye?ilel, Okan Zafer; Keskin, Seda; ?ahin, Onur

2014-02-01

402

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

403

Luminescent cadmium phenylenediacetate coordination polymers with bis(pyridylformyl)piperazine tethers: Influence of pendant arm position on topology  

NASA Astrophysics Data System (ADS)

Hydrothermal synthesis has generated divalent cadmium coordination polymers containing phenylenediacetate (phda) and bis(4-pyridylformyl)piperazine (bpfp) ligands, in which the position of the pendant acetate arms plays a very significant role in structure direction during self-assembly. [Cd(1,2-Hphda) 2(4-bpfp)] n ( 1) exhibits 2-D polymeric layers with embedded anti-syn bridged [Cd(OCO) 2] n ribbons. {[Cd(1,3-phda)(4-bpfp)(H 2O)] 2} n ( 2) has crystallographically independent (4,4) grids with different carboxylate binding modes, engaged in parallel interpenetration. {[Cd(1,4-phda)(4-bpfp)(H 2O)]} n ( 3) manifests acentric 1-D chains with an uncommon 4-connected 3 34 25 topology instilled by the mismatch in ligand length. Luminescent properties of all phases are also reported.

Wang, Curtis Y.; LaDuca, Robert L.

2010-11-01

404

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

405

Exact solution of the one-dimensional super-symmetric t-J model with unparallel boundary fields  

E-print Network

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 to 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.

Xin Zhang; Junpeng Cao; Wen-Li Yang; Kangjie Shi; Yupeng Wang

2013-12-02

406

Tuning structural topologies of five photoluminescent Cd(II) coordination polymers through modifying the substitute group of organic ligand  

NASA Astrophysics Data System (ADS)

Five new Cd(II) coordination polymers based on mixed 5-position substituted 1,3-benzenedicarboxylate ligands (R=?NO2/?OH/?CH3) and 1,4-bis(imidazol-1-yl)benzene (L1)or 1,4-bis(1-imidazol-yl) -2,5- dimethyl benzene (L2), namely [Cd(5-NO2-ip)(L1)·H2O] (1), [Cd(5-OH-ip)(L1)]n (2), [Cd(5-NO2-ip) (L1)0.5(H2O)2]n (3), {[Cd(5-NO2-ip)(L2)0.5(H2O)]·H2O} (4), [Cd(5-CH3-ip)(L2)(H2O)2]n (5), have been synthesized hydrothermally and structurally characterized. With different substituted groups in the organic ligands, five compounds exhibit five distinct framework structures. By changing the pH value, compound 1 with 2-fold interpenetrating (4,4)-layer structure and compound 3 with three-dimensional diamond-type framework are obtained, respectively, from the assembly of Cd(NO3)2·4H2O, 5-NO2-ip and L1 ligand. The replacement of 5-NO2-ip with 5-OH-ip leads to a compound 2 which features a doubly pillared layered structure with pcu topology. Compounds 4 and 5 are constructed from L2 ligand with 5-NO2-ip or 5-CH3-ip, respectively. Compound 4 has non-interpenetrating (4,4) layer, while compound 5 shows unusual 2D->3D polycatenation of bilayers. The results reveal a new approach toward tuning structural topologies of coordination polymers through modifying the substitute groups in organic ligands. Furthermore, the photoluminescent properties of compounds 1-5 have been studied in the solid state at room temperature.

Guo, Feng; Zhu, Baoyong; Xu, Guilan; Zhang, Miaomiao; Zhang, Xiuling; Zhang, Jian

2013-03-01

407

New Mg-based 4,4'-biphenyldicarboxylate coordination polymer with layered crystal structure.  

PubMed

New magnesium 4,4'-biphenyldicarboxylate (BPDC) was solvothermally synthesized in the presence of N,N'-dimethylformamide (DMF). The crystal structure with formula Mg(3)(BPDC)(3)(DMF)(4) and denoted as NICS-7 was solved in monoclinic symmetry with space group Pn (no. 7) and unit cell parameters a = 12.6433(7) Å, b = 13.3950(5) Å, c = 19.9230(8) A, beta = 107.131(5) °. The structure consists of MgO(6) linear arranged trimers with common vertices connected through BPDC ligands forming extended 2-dimensional layered hybrid structure. Each terminal Mg atom within trimeric clusters is coordinated by two dimethylformamide molecules, respectively. Layers of Mg(3)(BPDC)(3)(DMF)(4) are stabilized by non-coordinated dimethylformamide molecules located within the voids in crystallographically disordered manner. Thermal properties of NICS-7 were determined by thermogravimetric and temperature-programmed X-ray diffraction. The structure remains stable only up to 50 °C. At higher temperatures, the removal of non-coordinated dimethylformamide molecules causes formation of amorphous Mg-BPDC phase. PMID:25286197

Mazaj, Matjaž; Kasuni?, Marta; Kau?i?, Ven?eslav; Zabukovec-Logar, Nataša

2014-01-01

408

Exact Canonically Conjugate Momenta Approach to a One-Dimensional Neutron-Proton System, I  

E-print Network

Applying Tomonaga's idea to nuclei with the aid of Sunakawa's method, we developed a collective description of nuclear surface oscillations. It gives a microscopic foundation of nuclear collective motions in relation to Bohr-Mottelson model. Introducing collective variables, collective description is formulated with the first quantized language, contrary to the second quantized manner in Sunakawa's method for a Bose system. It overcomes difficulties remaining in traditional theoretical treatments of nuclear collective motions: Collective momenta in Tomonaga's manner are not exact canonically conjugate to collective coordinates and they are not independent. In contrast to the above collective description, Tomonaga first gave the another basic idea to approach elementary excitations in a Fermi system. The similar idea was also proposed by Luttinger. The Sunakawa's method for a Fermi system is anticipated to work well for such a problem. In this paper, on the isospin space, we define a density operator and following Tomonaga, introduce collective momentum. Then we develop an exact canonically momenta approach to a one-dimensional neutron-proton system.

Seiya Nishiyama; Joao da Providencia

2014-10-12

409

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

410

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

411

Synthesis, structure and properties of 2D lanthanide coordination polymers based on N-heterocyclic arylpolycarboxylate ligands.  

PubMed

The reaction of 3-(2,4-dicarboxyphenyl)-2,6-pyridinedicarboxylic acid (H4dppd) with rare earth nitrates under hydrothermal conditions generated a series of new two-dimensional (2D) coordination polymers, namely {[La(Hdppd)(H2O)2·(H2O)2]n (), [Ln2(Hdppd)2(H2O)4·(H2O)3]n [Ln = Sm (), Eu ()] and [Ln(Hdppd)(H2O)3·H2O]n [Ln = Gd (), Tb (), Dy (), Ho (), Er ()] [Hdppd = 3-(2,4-dicarboxyphenyl)-2,6-pyridinedicarboxylic trivalent anion]}. The complexes were characterized by X-ray single-crystal diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Luminescence spectroscopy of and showed bright red and green luminescences due to the 4f(n)-4f(n) transitions in Eu(3+) and Tb(3+) respectively, although the luminescence lifetime is shortened by non-radiative decay due to the presence of coordinating water molecules. The magnetic properties of were measured and discussed. Compound exhibits frequency dependent out-of-phase signals, and ferromagnetic coupling exists in . PMID:25331555

You, Li-Xin; Wang, Shu-Ju; Xiong, Gang; Ding, Fu; Meert, Katrien W; Poelman, Dirk; Smet, Philippe F; Ren, Bao-Yi; Tian, Yan-Wen; Sun, Ya-Guang

2014-11-01

412

Computational screening of structural and compositional factors for electrically conductive coordination polymers.  

PubMed

The combination of organic and inorganic chemical building blocks to form metal-organic frameworks (MOFs) offers opportunities for producing functional materials suitable for energy generation, storage and conversion. However, such applications rely on robust electron transport and the design of conductive hybrid materials is still in its infancy. Here we apply density functional theory to assess the important structural and compositional factors for forming conducting MOFs. We focus on 1D metal-organic polymers as a model system and assess the choice of organic, inorganic and linking units. The results demonstrate that electronic communication is sensitive to the energy and symmetry of the frontier orbitals associated with the organic and inorganic building blocks and offers guidance on how to optimise electrical conduction in hybrid materials. PMID:24569694

Tiana, Davide; Hendon, Christopher H; Walsh, Aron; Vaid, Thomas P

2014-07-28

413

Synthesis, structures, luminescent and magnetic properties of four coordination polymers with the flexible 1,3-phenylenediacetate ligands  

SciTech Connect

Four coordination polymers, [Zn(pda)(bpy)(H{sub 2}O)]{sub n}.nH{sub 2}O (1), [Cd(pda)(prz)(H{sub 2}O)]{sub n} (2), [Co{sub 3}({mu}{sub 3}-OH){sub 2}(pda){sub 2}(pyz)]{sub n}.2nH{sub 2}O (3) and [Pr{sub 2}(pda){sub 3}(H{sub 2}O){sub 2}]{sub n} (4) (H{sub 2}pda=1,3-phenylendiacetic acid, bpy=4,4'-bipyridine, prz=piperazine and pyz=pyrazine) have been hydrothermally synthesized and characterized. Complex 1 is a 1D wheel-like chain structure, which is further extended into a 3D metal-organic supramolecular framework by H-bonds and {pi}-{pi} stacking interactions. Complex 2 is a 1D ladder-like chain structure, which is also further extended into a 3D metal-organic supramolecular framework by H-bonds. Complex 3 possess a 2D sheet structure with infrequent two pairs of double-helix chains. Complex 4 features a 3D structure. Both 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of complexes 3 and 4 exhibit antiferromagnetic interactions between the nearest metal ions, with C=9.99 and 3.43 cm{sup 3} mol{sup -1} K, and {theta}=-23.9 and -46.3 K, respectively. -- Graphical abstract: Four new coordination polymers with 1,3-phenylenediacetate ligands have been hydrothermally synthesized and characterized. Complexes 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of 3 and 4 exhibit antiferromagnetic interactions between the nearest metal centers. Display Omitted Research highlights: > Coordinative property of H{sub 2}pda ligand was shown when bonded by different block metals. > Careful selection of co-ligand and metals resulted in dramatic framework evolution. > (c) The compounds constructed with Zn{sup 2+} and Cd{sup 2+} exhibit strong blue fluorescent emission. > The magneto-structural correlation of the complexes constructed with Co{sup 2+} and Pr{sup 3+} was elucidated.

Gu, Jin-Zhong, E-mail: gujzh@lzu.edu.c [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Lv, Dong-Yu [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Gao, Zhu-Qing [School of Chemistry and Biology Engineering, Taiyuan University of Science and Technology, Taiyuan 030021 (China); Liu, Jian-Zhao; Dou, Wei; Tang, Yu [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

2011-03-15

414

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

415

Quantum teleportation in one-dimensional quantum dots system Hefeng Wang, Sabre Kais *  

E-print Network

Quantum teleportation in one-dimensional quantum dots system Hefeng Wang, Sabre Kais * Department of quantum teleportation protocol based on one-dimensional quantum dots system. Three quantum dots with three electrons are used to perform teleportation, the unknown qubit is encoded using one electron spin on quantum

Kais, Sabre

416

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 atomically precise nanostructures at surfaces, particularly nanowires consisting of atom chains; (2) explore the behavior of one-dimensional electrons in atomic chains; (3) find the fundamental limits of data storage

Himpsel, Franz J.

417

One-Dimensional Metal Oxide Nanotubes, Nanowires, Nanoribbons, and Nanorods: Synthesis, Characterizations, Properties and Applications  

Microsoft Academic Search

One dimensional nanomaterials have attracted much attention from academia and industry. A large series of devices have been created on the basis of 1D nanomaterials. Their applications have changed and will continuously change our daily life. In this paper, we will present a comprehensive review on the synthesis, structure characterization, properties and actual and future potential applications of one dimensional

Yu Li; Xiao-Yu Yang; Yi Feng; Zhong-Yong Yuan; Bao-Lian Su

2012-01-01

418

The Application of the Extended Conjugate Gradient Method on the One-Dimensional Energized Wave Equation  

Microsoft Academic Search

This paper computes the optimal control and state of the one-dimensional Energized wave equation using the Extended Conjugate gradient Method (ECGM. We recalled all vital computational issues in the implementation of the ECGM algorithm on the one-dimensional Energized Wave equation in the paper. With these recalls, program codes were derived which gave various numerical optima controls and states. These optimal

Victor O. Waziri; Sunday A. Reju

419

Photoinduced Metallic Properties of One-Dimensional Strongly Correlated Electron Systems  

Microsoft Academic Search

We study photoinduced optical responses of one-dimensional strongly correlated electron systems. Optical conductivity spectra are calculated for the ground and photoexcited states in a one-dimensional Hubbard model at half filling by the exact diagonalization method. It is found that, in the Mott insulator phase, the photoexcited state has large spectral weights including the Drude weight below the optical gap. As

Nobuya Maeshima; Kenji Yonemitsu

2005-01-01

420

Sufficient conditions for a period increment big bang bifurcation in one-dimensional maps  

E-print Network

Sufficient conditions for a period increment big bang bifurcation in one-dimensional maps Viktor bang bifurcation of the period increment type, it is sufficient for a one-dimensional map: organizing centers, piecewise-smooth maps, border collision bifurcations 1 Introduction Big bang bifurcations

421

Optimal one-dimensional inversion and bounding of magnetotelluric apparent resistivity and phase measurements  

Microsoft Academic Search

The properties of the log of the admittance in the complex frequency plane lead to an integral representation for one-dimensional magnetotelluric (MT) apparent resistivity and impedance phase similar to that found previously for complex admittance. The inverse problem of finding a one-dimensional model for MT data can then be solved using the same techniques as for complex admittance, with similar

Robert L. Parker; John R. Booker

1996-01-01

422

Black-box decomposition approach for computational hemodynamics: One-dimensional models  

E-print Network

Black-box decomposition approach for computational hemodynamics: One-dimensional models P. In this context, effective and black-box-type decomposition strategies for one-dimensional networks are needed, so size. Effective iterative strategies for the nonlinear system that preserve the black- box character

Buscaglia, Gustavo C.

423

Quantum phase transition and Coulomb blockade with one-dimensional SQUID arrays  

E-print Network

Quantum phase transition and Coulomb blockade with one-dimensional SQUID arrays Michio Watanabe a-dimensional arrays of small-capacitance super- conducting quantum interference devices (SQUIDs), where an external; Fig. 1. A scanning electron micrograph of a one-dimensional SQUID array. The electromagnetic

Haviland, David

424

Entanglement and Quantum Phase Transition in a One-Dimensional System of quantum Dots with Disorder  

E-print Network

Entanglement and Quantum Phase Transition in a One-Dimensional System of quantum Dots with Disorder We study the entanglement of formation and quantum phase transition in a one-dimensional quantum dots, quantum computer based on quantum dots is a prominent one[9, 10]. Quantum dots are clusters of atoms

Kais, Sabre

425

Effective mass enhancement of two-dimensional electrons in a one-dimensional superlattice potential  

E-print Network

Effective mass enhancement of two-dimensional electrons in a one-dimensional superlattice potential effective mass enhancement of two-dimensional 2D electrons in an atomically precise one-dimensional Al reveal that the mobility of the 2D electrons increases with electron density n2D . At low densities (n2D

Rokhinson, Leonid

426

Synthesis, characterisation and properties of a new three-dimensional Yttrium Europium coordination polymer  

NASA Astrophysics Data System (ADS)

A new three-dimensional europium-doped Yttrium(III) tricarboxylate, MIL-92 LT1 or Y 1- xEu x(H 2O) 2{C 6H 3sbnd (CO 2) 3} ( x˜0.03) (LT: Low Temperature) has been synthesised hydrothermally. Its three-dimensional structure, determined using X-ray powder diffraction data, is built-up from isolated eight coordinated Ln(III) monocapped square antiprisms ( Ln=Y, Eu) linked through carboxylate moieties. Its thermal behaviour, investigated using TGA and X-ray thermodiffractometry indicates that dehydration is irreversible giving the solid MIL-92 HT or Y 1- xEu x{C 6H 3sbnd (CO 2) 3} ( x˜0.03) (HT: High Temperature). It induces a change in the connection mode of the carboxylate and a decrease in the coordination number of the rare-earth leading to an unusual octahedral environment for the rare-earth cation. After a structural analysis of the reconstructive phase transition, the optical properties of these solids have been investigated and show that dehydration leads to a strong increase in the optical output. Crystal data for MIL-92 LT: monoclinic space group C2/c (n° 15) with a=16.428(1) Å, b=6.071(1) Å, c=20.404(1) Å, ?=95.31(3)° and Z=2. Crystal data for MIL-92 HT: monoclinic space group C2/c (n° 15) with a=17.390(1) Å, b=5.521(1) Å, c=19.487(1) Å, ?=105.35(2)° and Z=2.

Surblé, Suzy; Serre, Christian; Millange, Franck; Pelle, Fabienne; Férey, Gérard

2005-09-01

427

A novel two-dimensional Cd(II) coordination polymer: poly[aqua[?4-2-(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

2014-11-15

428

A new calcium trimellitate coordination polymer with a chain-like structure  

NASA Astrophysics Data System (ADS)

The calcium trimellitate, Ca(H 2O)[(O 2C) 2-C 6H 3-CO 2H], was hydrothermally synthesized from a mixture of calcium hydroxide, 1,2,4-benzenetricarboxylic (or trimellitic) acid and water at 180 °C for 24 h (under autogenous pressure). Its crystal structure has been determined by single-crystal X-ray diffraction analysis using synchrotron radiation (station 9.8, SRS Daresbury, UK). It consists of infinite chains of calcium bicapped trigonal prismatic polyhedra connected to each other through the 1,2,4-benzenetricarboxylate ligand. The eight-fold coordinated calcium cation is bonded to one terminal water molecule, two carboxylate groups with a chelating conformation and three carboxylate groups in a monodentating mode. One of the monodentate carboxylate is terminal with the occurrence of protonated C-OH bonding. Triclinic space group P-1 with a = 6.9073(4) Å, b = 6.9917(4) Å, c = 10.3561(6) Å, ? = 87.178(1)°, ? = 83.233(1)°, ? = 69.576(1)°, V = 465.41(5) Å 3.

Volkringer, Christophe; Loiseau, Thierry; Férey, Gérard; Warren, John E.; Wragg, David S.; Morris, Russell E.

2007-06-01

429

Hydrothermal synthesis and characteristics of 3-D hydrated bismuth oxalate coordination polymers with open-channel structure  

SciTech Connect

Two new 3-D porous bismuth coordination polymers, (C{sub 5}NH{sub 6}){sub 2}[Bi{sub 2}(H{sub 2}O){sub 2}(C{sub 2}O{sub 4}){sub 4}].2H{sub 2}O 1 and (NH{sub 4})[Bi(C{sub 2}O{sub 4}){sub 2}].3H{sub 2}O 2, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic symmetry, P2{sub 1}/c space group with a=10.378(2) A, b=17.285(3) A, c=16.563(5) A, {alpha}=90 deg., {beta}=119.66(2) deg., {gamma}=90 deg., V=2581.8(10) A{sup 3}, Z=4, R{sub 1}=0.0355 and wR{sub 2}=0.0658 for unique 4713 reflections I >2{sigma}(I). Compound 2 crystallizes in the tetragonal symmetry, I4{sub 1}/amd space group with a=11.7026(17) A, b=11.7026(17) A, c=9.2233(18) A, {alpha}=90 deg., {beta}=90 deg., {gamma}=90 deg., V=1263.1(4) A{sup 3}, Z=32, R{sub 1}=0.0208 and wR{sub 2}=0.0518 for unique 359 reflections I> 2{sigma}(I). Compounds 1 and 2 are 3-D open-framework structures with a 6{sup 6} uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers, study of ultrasonic treatment on 2 indicates the replacement of NH{sub 4}{sup +} by K{sup +} on potassium ion exchange. Thermogravimetric analysis indicates that the open-channel frameworks are thermally stable up to 200 deg. C, and other characterizations are also described by elemental analysis, IR and ultraviolet-visible diffuse reflectionintegral spectrum (UV-Vis DRIS). - Graphical abstract: Two novel 3-D extended porous coordination polymers have been synthesized by hydrothermal method. Both compounds are 3-D open-framework structures with a 6{sup 6} uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers. Study of ultrasonic treatment on 2 indicates the replacement of NH{sub 4}{sup +} by K{sup +} on potassium ion exchange.

Chen Xinxiang; Cao Yanning [Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); Zhang Hanhui [Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)], E-mail: zhanghh1840@hotmail.com; Chen Yiping; Chen Xuehuan; Chai Xiaochuan [Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China)

2008-05-15

430