Three Dimensional Structure-Electrical Properties of Oriented PPV and PANI Films

2003 ◽  
Author(s):  
Runqing Ou ◽  
Robert J. Samuels ◽  
Rosario A. Gerhardt
Keyword(s):  
Electrical Properties ◽  
Three Dimensional ◽  
The Other ◽  
Planar Structure ◽  
Dimensional Structure ◽  
Phenylene Vinylene ◽  
Random Orientation ◽  
Waveguide Coupler ◽  
Impedance Measurements ◽  
Oriented Films

In this paper the influence of anisotropic molecular structure on the three dimensional electrical properties of both poly(phenylene vinylene), (PPV), and polyaniline, (PANI) oriented films is investigated. The anisotropic structure of the stretched PPV and PANI EB films were examined using a modified waveguide coupler while three dimensional impedance spectroscopy measurements were made using specially designed test fixtures that allowed the in-plane as well as the through-plane impedance to be measured. The unstretched PANI EB film has a random orientation and one-way stretching leads to a uniaxial structure. The unstretched PPV film, on the other hand, was found to have a highly planar structure and oneway stretching converts the planar structure to a uniaxial structure. Impedance measurements were made on PANI after it was doped with HCl while PPV films were measured in the undoped state. For HCl-doped PANI films, the conductivity along the stretch direction was found to increase with orientation. For undoped PPV films, the conductivity through the film thickness direction decreased with increasing orientation. For both polymers, the in-plane conductivity was significantly greater than the through-plane conductivity.

A new three-dimensional anionic cadmium(II) dicyanamide network

2014 ◽  
Vol 70 (11) ◽  
pp. 1054-1056 ◽  
Author(s):  
Qiang Li ◽  
Hui-Ting Wang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Unit Cell Volume ◽  
Three Dimensional ◽  
Building Blocks ◽  
The Other ◽  
Dimensional Structure ◽  
Cadmium Nitrate ◽  
Nitrate Tetrahydrate ◽  
Anionic Framework

A new cadmium dicyanamide complex, poly[tetramethylphosphonium [μ-chlorido-di-μ-dicyanamido-κ4N1:N5-cadmium(II)]], [(CH3)4P][Cd(NCNCN)2Cl], was synthesized by the reaction of tetramethylphosphonium chloride, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each CdIIatom is octahedrally coordinated by four terminal N atoms from four anionic dicyanamide (dca) ligands and by two chloride ligands. The dicyanamide ligands play two different roles in the building up of the structure; one role results in the formation of [Cd(dca)Cl]2building blocks, while the other links the building blocks into a three-dimensional structure. The anionic framework exhibits a solvent-accessible void of 673.8 Å3, amounting to 47.44% of the total unit-cell volume. The cavities in the network are occupied by pairs of tetramethylphosphonium cations.

scholarly journals Bis(μ2-4-nitrophenolato)bis(4-nitrophenolato)di-μ3-oxido-octaphenyltetratin chloroform sesquisolvate [+ solvate]: a tetranuclear stannoxane

IUCrData ◽  
2019 ◽  
Vol 4 (8) ◽  
Author(s):  
Patrick Butler
Keyword(s):  
Hydrogen Bonds ◽  
Electron Density ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Coordination Geometry ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Complex Molecules ◽  
Three Dimensional Structure

The title tetranuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex molecules, A and B, in the asymmetric unit together with 1.5 molecules of chloroform. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex molecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex molecules are linked by a number of C—H...O hydrogen bonds within the layers and between the layers, forming a supramolecular three-dimensional structure.

Supercoils in plant DNA: nucleoid sedimentation studies

1988 ◽  
Vol 89 (2) ◽  
pp. 243-252
Author(s):  
L.M. Stoilov ◽  
J.S. Zlatanova ◽  
A.P. Vassileva ◽  
M.G. Ivanchenko ◽  
C.P. Krachmarov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gamma Irradiation ◽  
Protein Content ◽  
Ethidium Bromide ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Salt Treatment ◽  
Plant Dna ◽  
Ionic Detergent

Plant nuclei have been studied with respect to the three-dimensional structure of DNA. Nucleoids derived from nuclei by non-ionic detergent and high salt treatment were analysed by sedimentation in a series of sucrose gradients containing increasing amounts of the intercalating agent ethidium bromide. In addition the nucleoid sedimentation behaviour was investigated following gamma irradiation. The results show that plant DNA is supercoiled, as is the DNA from the other eukaryotes studied, and contains approximately the same concentration of superhelical turns but probably relatively fewer DNA superhelical loops. The plant nuclear populations in all cases studied give rise to two distinct nucleoid bands. These have been characterized by electron microscopy and by their DNA and protein content. The possible origin of the two bands is discussed.

Poly[deca-μ2-cyanido-dicyanidobis(μ2-ethylenediamine)bis(ethylenediamine)tricadmium(II)dicobalt(III)]: a two-dimensional coordination polymer

2009 ◽  
Vol 65 (3) ◽  
pp. m118-m120
Author(s):  
Olha Sereda ◽  
Helen Stoeckli-Evans
Keyword(s):  
Coordination Polymer ◽  
Network Structure ◽  
General Position ◽  
Rotation Axis ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Dimensional Network

The title coordination polymer, [Cd3Co2(CN)12(C2H8N2)4]n, has an infinite two-dimensional network structure. The asymmetric unit is composed of two crystallographically independent CdIIatoms, one of which is located on a twofold rotation axis. There are two independent ethylenediamine (en) ligands, one of which bis-chelates to the Cd atom that sits in a general position, while the other bridges this Cd atom to that sitting on the twofold axis. The Cd atom located on the twofold rotation axis is linked to four equivalent CoIIIatomsviacyanide bridges, while the Cd atom that sits in a general position is connected to three equivalent CoIIIatomsviacyanide bridges. In this way, a series of trinuclear, tetranuclear and pentanuclear macrocycles are linked to form a two-dimensional network structure lying parallel to thebcplane. In the crystal structure, these two-dimensional networks are linkedviaN—H...N hydrogen bonds involving an en NH2H atom and a cyanide N atom, leading to the formation of a three-dimensional structure. This coordination polymer is only the second example involving a cyanometallate where the en ligand is present in both chelating and bridging coordination modes.

A three-dimensional zinc-based coordination polymer built from 5-carboxylato-1-carboxylatomethyl-2-oxidopyridinium with a 4-connectedsratopology

2014 ◽  
Vol 70 (8) ◽  
pp. 801-804
Author(s):  
De-Yun Ma ◽  
Jing Zheng ◽  
Jie-Qiong Cao ◽  
Xu-Min Lin ◽  
You-Biao Ling
Keyword(s):  
Coordination Polymer ◽  
Luminescence Spectrum ◽  
Room Temperature ◽  
Three Dimensional ◽  
The Other ◽  
Planar Structure ◽  
Zigzag Chain ◽  
Carboxylate Group ◽  
Aromatic Carboxylate ◽  
Bidentate Mode

A novel three-dimensional ZnIIcomplex, poly[aqua(μ4-5-carboxylato-1-carboxylatomethyl-2-oxidopyridinium)zinc(II)], [Zn(C8H5NO4)(H2O)]n, has been prepared by hydrothermal assembly of Zn(CH3COO)2·2H2O and 5-carboxy-1-(carboxymethyl)pyridin-1-ium-2-olate (H2ccop). The ccop2−anions bridge the ZnIIcations in a head-to-tail fashionviamonodentate aromatic carboxylate and phenolate O atoms to form an extended zigzag chain which runs parallel to the [011] direction. One O atom of the aliphatic carboxylate group of the ccop2−ligand coordinates to the ZnIIatom of a neighbouring chain thereby producing undulating layers which lie parallel to the (01-1) plane. A similar parallel undulating planar structure can be obtained if a path involving the other O atom of the aliphatic carboxylate group is considered. Thus, the aliphatic carboxylate group acts in a bridging bidentate mode to give extended –Zn–O–C–O–Zn– sequences running parallel to [001] which link the layers into an overall three-dimensional framework. The three-dimensional framework can be simplified as a 4-connected sra topology with a Schläfli symbol of 42.63.8 if all the ZnIIcentres and ccop2−anions are regarded as tetrahedral 4-connected nodes. The three-dimensional luminescence spectrum was measured at room temperature with excitation and emission wavelengths of 344–354 and 360–630 nm, respectively, at intervals of 0.15 and 2 nm, respectively.

scholarly journals Synthesis and crystallographic characterization of a mononuclear cobalt(III) complex possessing both thiolate and thioether donors: reactivity of an thiolate-bridged pentanuclear Co2Ag3complex with iodomethane

2017 ◽  
Vol 73 (5) ◽  
pp. 678-681
Author(s):  
Yosuke Fukuda ◽  
Nobuto Yoshinari ◽  
Takumi Konno
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Mononuclear Complex ◽  
The Other ◽  
Dimensional Structure ◽  
Cationic Complex ◽  
Three Dimensional Structure ◽  
Mononuclear Cobalt

Treatment of an S-bridged pentanuclear AgI3CoIII2complex, [Ag3{Co(L)}2]3+[L3–= N(CH2NHCH2CH2S−)3], in which two tris(thiolate)-type mononuclear CoIIIunits ([Co(L)]) are bridged by three AgIions through S atoms, with iodomethane (CH3I) gave a new CoIIImononuclear complex, [Co(LMe2)]2+[LMe2−= N(CH2NHCH2CH2S−)(CH2NHCH2CH2SCH3)2], systematic name: {2-[(bis{[2-(methylsulfanyl)ethyl]aminomethyl}aminomethyl)amino]ethanethiolato}cobalt(III) bis(hexafluoridophosphate). This cationic complex was crystallized with PF6−anions to form the title compound, [Co(LMe2)](PF6)2. In the [Co(LMe2)]2+cation, two of three thiolate groups in [Co(L)] are methylated while one thiolate group remains unreacted. Although a total of eight stereoisomers are possible for [Co(LMe2)]2+, only a pair of enantiomers {ΛRR- and ΔSS-[Co(LMe2)]2+} are selectively formed. In the crystal, the complex cations and the PF6−anions are connected through weak N—H...F, C—H...F and C—H...S hydrogen bonds into a three-dimensional structure. Two F atoms in one PF6anion are disordered over two sets of sites with refined occupancies of 0.61 (4) and 0.39 (4) and two F atoms in the other PF6−anion are disordered over two sets of sites with occupancies of 0.5.

Development of a Self-Opening Neural Interface

2013 ◽  
Vol 7 (2) ◽  
Author(s):  
Annarita Cutrone ◽  
Sivia Bossi ◽  
Silvestro Micera
Keyword(s):  
Electrical Properties ◽  
Nervous Tissue ◽  
Three Dimensional ◽  
Mechanical Tests ◽  
Neural Interface ◽  
Dimensional Structure ◽  
Biocompatible Polymer ◽  
Three Dimensional Structure ◽  
Preliminary Results ◽  
Mechanical And Electrical Properties

This article illustrates the development and preliminary results of SELINE, a self-opening neural interface. The advantages of this innovative neural interface are: higher selectivity due to its three-dimensional structure and efficient anchorage system to the nervous tissue. The device is made of polyimide that is a lightweight, flexible and biocompatible polymer. The electrode has been microfabricated using lithographic techniques; electrical and mechanical tests have been performed to evaluate the integrity of the device. Successful results have been obtained in the development of the electrode with excellent mechanical and electrical properties.

scholarly journals Structure-function relationships in the cysteine proteinases actinidin, papain and papaya proteinase Ω. Three-dimensional structure of papaya proteinase Ω deduced by knowledge-based modelling and active-centre characteristics determined by two-hydronic-state reactivity probe kinetics and kinetics of catalysis

1991 ◽  
Vol 280 (1) ◽  
pp. 79-92 ◽  
Author(s):  
C M Topham ◽  
E Salih ◽  
C Frazao ◽  
D Kowlessur ◽  
J P Overington ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Catalytic Site ◽  
The Other ◽  
Dimensional Structure ◽  
Cysteine Proteinases ◽  
Three Dimensional Structure ◽  
Knowledge Based ◽  
Thiol Reactivity ◽  
Ph Dependent ◽  
Kinetics Of

1. A model of the three-dimensional structure of papaya proteinase omega, the most basic cysteine proteinase component of the latex of papaya (Carica papaya), was built from its amino acid sequence and the two currently known high-resolution crystal structures of the homologous enzymes papain (EC 3.4.22.2) and actinidin (EC 3.4.22.14). The method used a knowledge-based approach incorporated in the COMPOSER suite of programs and refinement by using the interactive graphics program FRODO on an Evans and Sutherland PS 390 and by energy minimization using the GROMOS program library. 2. Functional similarities and differences between the three cysteine proteinases revealed by analysis of pH-dependent kinetics of the acylation process of the catalytic act and of the reactions of the enzyme catalytic sites with substrate-derived 2-pyridyl disulphides as two-hydronic-state reactivity probes are reported and discussed in terms of the knowledge-based model. 3. To facilitate analysis of complex pH-dependent kinetic data, a multitasking application program (SKETCHER) for parameter estimation by interactive manipulation of calculated curves and a simple method of writing down pH-dependent kinetic equations for reactions involving any number of reactive hydronic states by using information matrices were developed. 4. Papaya proteinase omega differs from the other two enzymes in the ionization characteristics of the common (Cys)-SH/(His)-Im+H catalytic-site system and of the other acid/base groups that modulate thiol reactivity towards substrate-derived inhibitors and the acylation process of the catalytic act. The most marked difference in the Cys/His system is that the pKa for the loss of the ion-pair state to form -S-/-Im is 8.1-8.3 for papaya proteinase omega, whereas it is 9.5 for both actinidin and papain. Papaya proteinase omega is similar to actinidin in that it lacks the second catalytically influential group with pKa approx. 4 present in papain and possesses a catalytically influential group with pKa 5.5-6.0. 5. Papaya proteinase omega occupies an intermediate position between actinidin and papain in the sensitivity with which hydrophobic interaction in the S2 subsite is transmitted to produce changes in transition-state geometry in the catalytic site, a fact that may be linked with differences in specificity in P2-S2 interaction exhibited by the three enzymes.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Three-Dimensional Structure and Disposition of the Air Conducting and Gas Exchange Conduits of the Avian Lung: The Domestic Duck (Cairina moschata)

ISRN Anatomy ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
A. N. Makanya ◽  
B. M. Kavoi ◽  
V. Djonov
Keyword(s):  
Light Transmission ◽  
Three Dimensional ◽  
Lung Parenchyma ◽  
The Other ◽  
Dimensional Structure ◽  
Domestic Duck ◽  
Remarkable Similarity ◽  
Cairina Moschata ◽  
Avian Lung ◽  
Scanning Electron

The anatomy of the domestic duck lung was studied macroscopically, by casting and by light, transmission, and scanning electron microscopy. The lung had four categories of secondary bronchi (SB), namely, the medioventral (MV, 4-5), laterodorsal (LD, 6–10), lateroventral (LV, 2–4), and posterior secondary bronchi (PO, 36–44). The neopulmonic parabronchi formed an intricate feltwork on the ventral third of the lung and inosculated those from the other SB. The lung parenchyma was organized into cylindrical parabronchi separated by thin septa containing blood vessels. Atria were shallow and well-fortified by epithelial ridges reinforced by smooth muscle bundles and gave rise to 2–6 elongate infundibulae. Air capillaries arose either directly from the atria or from infundibulae and were tubular or globular in shape with thin interconnecting branches. The newly described spatial disposition of the conducting air conduits closely resembles that of the chicken. This remarkable similarity between the categories, numbers, and 3D arrangement of the SB in the duck and chicken points to a convergence in function-oriented design. To illuminate airflow dynamics in the avian lung, precise directions of airflow in the various categories of SB and parabronchi need to be characterized.

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