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Full-Text Articles in Chemistry

Charge Density Wave Caused By Reducing Thse3 By One Electron. Superstructure And Short-Range Order In Ath2se6 (A = K, Rb) Studied By X-Ray Diffraction, Electron Diffraction, And Diffuse Scattering, Kyoung-Shin Choi, Rhonda Patschke, Simon Billinge, Mark Waner, Marcos Dantus, Mercouri Kanatzidis Oct 1998

Charge Density Wave Caused By Reducing Thse3 By One Electron. Superstructure And Short-Range Order In Ath2se6 (A = K, Rb) Studied By X-Ray Diffraction, Electron Diffraction, And Diffuse Scattering, Kyoung-Shin Choi, Rhonda Patschke, Simon Billinge, Mark Waner, Marcos Dantus, Mercouri Kanatzidis

Mark J. Waner

Charge Density Wave Caused by Reducing ThSe3 by One Electron. Superstructure and Short-Range Order in ATh2Se6 (A = K, Rb) Studied by X-ray Diffraction, Electron Diffraction, and Diffuse Scattering


Two-Surface Virial Analysis Of Alkane Adsorption On Carbopack C With And Without Hydrogen Treatment., Chrystal Bruce, Thomas Rybolt, Howard Thomas, Tara Agnew, Brandon Davis Oct 1998

Two-Surface Virial Analysis Of Alkane Adsorption On Carbopack C With And Without Hydrogen Treatment., Chrystal Bruce, Thomas Rybolt, Howard Thomas, Tara Agnew, Brandon Davis

Chrystal D. Bruce

Second gas–solid virial coefficients for propane, butane, pentane, and hexane were found for Carbopack C and Carbopack C-HT (Supelco Inc.) within the temperature range of 323 to 471 K using gas–solid chromatography in the Henry's law region of adsorption. Carbopack C and Carbopack C-HT are both graphitized carbon black powders. Treatment of Carbopack C with hydrogen at 1273 K converts it to Carbopack C-HT and is believed to remove certain high energy sites or “hot spots” from the carbon surface. These two surfaces provide appropriate model systems to test a two-surface virial analysis. Surface areas for both powders were calculated …


The Voltammetry Of Fullerenes And Metallofullerenes, Mark Anderson Oct 1998

The Voltammetry Of Fullerenes And Metallofullerenes, Mark Anderson

Mark R. Anderson

No abstract is available at this time.


The Voltammetry Of Metallofullerenes, Mark Anderson Sep 1998

The Voltammetry Of Metallofullerenes, Mark Anderson

Mark R. Anderson

No abstract is available at this time.


2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George Jul 1998

2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George

Nigam Rath

The reaction of 3-aryl-2-cyano-5,5-bis(methylthio)penta-2,4-dienenitrile, (1), with (L)-(-)-2-hydroxymethylpyrrolidine, (2), gave two types of product, the normal substitution product, (3), and a pyridine derivative, (4). The structures of two representative examples, 2-phenyl-3-(5,6,7,7a-tetrahydro1H,3H-pyrrolo[1,2-c]oxazol-3-ylidene)-1-propene-1,1-dicarbonitrile, (3a), as its hemibenzene solvate, C17H14N3O.0.5C6H6, and 4-(4-methoxyphenyl)-2,6-bis(methylthio)pyridine-3-carbonitrile, (4b), C15H14N2OS2, have been unambiguously established by X-ray crystallographic analysis. The molecular packing of (4b) involves loosly held dimers with S1...S1' distances of 3.424 (1) Å.


Isolation And Structure Of Sc2@C74, Harry Dorn, Steven Stevenson, Paul Burbank, Kim Harich, Z. Sun, T. Glass, Mark Anderson, Donald Bethune, M. Sherwood May 1998

Isolation And Structure Of Sc2@C74, Harry Dorn, Steven Stevenson, Paul Burbank, Kim Harich, Z. Sun, T. Glass, Mark Anderson, Donald Bethune, M. Sherwood

Mark R. Anderson

No abstract is currently available.


Spectroscopic Probes Of Bonded Interfaces, Mark Anderson, C. Douglas Taylor, Cynthia Kraft Apr 1998

Spectroscopic Probes Of Bonded Interfaces, Mark Anderson, C. Douglas Taylor, Cynthia Kraft

Mark R. Anderson

No abstract is currently available.


The Electrochemistry Of Fullerenes And Metallofullerenes, Mark Anderson Apr 1998

The Electrochemistry Of Fullerenes And Metallofullerenes, Mark Anderson

Mark R. Anderson

No abstract is available at this time.


Studies Of Molecular Priming For Adhesive Interactions, C, Douglas Taylor, Mark Anderson Apr 1998

Studies Of Molecular Priming For Adhesive Interactions, C, Douglas Taylor, Mark Anderson

Mark R. Anderson

No abstract is currently available.


Sublimation Enthalpies At 298.15 K Using Correlation Gas Chromatography And Differential Scanning Calorimetry Measurements, James Chickos, Donald Hesse, Sarah Hosseini, Gary Nichols, Paul Webb Mar 1998

Sublimation Enthalpies At 298.15 K Using Correlation Gas Chromatography And Differential Scanning Calorimetry Measurements, James Chickos, Donald Hesse, Sarah Hosseini, Gary Nichols, Paul Webb

James Chickos

No abstract provided.


Synthesis Of Licoo2 Powders For Lithium-Ion Batteries From Precursors Derived By Rotary Evaporation., P. Kumpta, D. Gallet, A. Waghray, G. Blomgren, Michael Setter Mar 1998

Synthesis Of Licoo2 Powders For Lithium-Ion Batteries From Precursors Derived By Rotary Evaporation., P. Kumpta, D. Gallet, A. Waghray, G. Blomgren, Michael Setter

Michael P. Setter

Lithium cobalt oxide (LiCoO2) has received considerable attention in the last few years and is a well-known cathode material for high voltage (4 V) rechargeable Li-ion batteries. A simple chemical approach based on aqueous solution chemistry has been developed to synthesize molecularly mixed amorphous precursors. The precursors begin to transform to form LiCoO2 upon heat treatment at temperatures as low as 400°C. Strong peaks characteristic of the desired high temperature (HT) phase of LiCoO2 evolve when the precursors are heat treated to 800°C for 2 h. The morphology and particle size of the powders have been examined using scanning electron …


The Voltammetry Of C84 Isomers, Mark Anderson, Harry Dorn, Steven Stevenson, Susanne Dana Mar 1998

The Voltammetry Of C84 Isomers, Mark Anderson, Harry Dorn, Steven Stevenson, Susanne Dana

Mark R. Anderson

The square-wave voltammetry of isolated isomers of C84 is reported. Based on their relative abundance, the isomers are assumed to have D2 and D2d symmetry. The D2 isomer has four reversible reductions at −0.65, −0.98, −1.34, and −1.75 V versus Fc/Fc+ prior to electrolyte decomposition. This behavior is consistent with previous reports, and is similar to the voltammetry of C60 and C70 (e.g. sequential reductions spaced at slightly increasing intervals). The D2d isomer has five reversible reductions at −0.46, −0.77, −1.58, −1.98, and −2.27 V versus Fc/Fc+ prior to the onset of electrolyte decomposition. The large potential difference separating the …


A Protocol For Correcting Experimental Fusion Enthalpies To 298.15 K And It's Application In Indirect Measurements Of Sublimation Enthalpy At 298.15 K, James S. Chickos Feb 1998

A Protocol For Correcting Experimental Fusion Enthalpies To 298.15 K And It's Application In Indirect Measurements Of Sublimation Enthalpy At 298.15 K, James S. Chickos

James Chickos

No abstract provided.


Imaging The Molecular Dimensions And Oligomerization Of Proteins At Liquid/Solid Interfaces, Mark Waner, Martha Gilchrist, Melvin Schindler, Marcos Dantus Feb 1998

Imaging The Molecular Dimensions And Oligomerization Of Proteins At Liquid/Solid Interfaces, Mark Waner, Martha Gilchrist, Melvin Schindler, Marcos Dantus

Mark J. Waner

Individual Concanavalin A (ConA) molecules have been imaged at the liquid/solid interface with an atomic force microscope (AFM). Three-dimensional sizing with very high resolution (<5 Å) has been obtained by a novel approach based on height distributions, which avoids the tip convolution effects which normally affect scanning probe microscopy techniques. Each height measurement correlates to a particular molecular orientation on the surface. A large number of such measurements provide a statistical ensemble of orientations. The complete height distribution reflects the three-dimensional size of the protein sample and hence its tertiary and quaternary structure. A surface adsorption and orientation model, based on a minimization of surface adsorption energy, is proposed. This model is in good agreement with the observed height distribution of Con A molecules at the liquid/solid interface. Analysis of Con A and succinylated Con A molecules on mica demonstrates that Con A dimers are the prevalent species at the liquid/solid interface. This is in contrast to the tetrameric organization of Con A normally observed in solution. The new possibilities opened by height distribution analysis on the physical characterization of biomolecules at interfaces are also discussed.


Isolation And Structure Of Sc2@C74 And Sc2@C76, Harry Dorn, Steven Stevenson, Paul Burbank, Kim Harich, Z. Sun, T. Glass, Mark Anderson, Donald Bethune, M. Sherwood Dec 1997

Isolation And Structure Of Sc2@C74 And Sc2@C76, Harry Dorn, Steven Stevenson, Paul Burbank, Kim Harich, Z. Sun, T. Glass, Mark Anderson, Donald Bethune, M. Sherwood

Mark R. Anderson

No abstract is currently available.


High Performance Liquid Chromatographic Analysis Of Amino Acid- And Dipeptide-Derived Chloramines, Thomas Goyne, Suzanne Furness-Green, Tracy Inskeep, Jennifer Starke, Lu Ping, Heather Greenleaf-Schumann Dec 1997

High Performance Liquid Chromatographic Analysis Of Amino Acid- And Dipeptide-Derived Chloramines, Thomas Goyne, Suzanne Furness-Green, Tracy Inskeep, Jennifer Starke, Lu Ping, Heather Greenleaf-Schumann

Thomas Goyne

No abstract provided.


Tight-Binding Simulations Of Argon Cation Clusters, Guillermo A. Morales, Jessica Faulkner, Randall W. Hall Dec 1997

Tight-Binding Simulations Of Argon Cation Clusters, Guillermo A. Morales, Jessica Faulkner, Randall W. Hall

Randall W. Hall

A simple, semiempirical model was used to study the ground and excited stateproperties of argon cation clusters at 60 K. The model is a tight-binding Hamiltonian whose parameters are determined from atomic and diatomic properties.Monte Carlo simulations were used to calculate the average properties of these clusters. The photoabsorptionspectrum was in good agreement with previous calculations and experiments. The splitting of the photoabsorptionspectrum for clusters with greater than 14 atoms was investigated. The two excited states corresponding to the splitting arise from a 3-atom ion core, perturbed by a 4th atom, with solvation from the remaining atoms. The perturbation of …


Exo- And Endo-Tricarbonyl[(4b,5,6,7,8,8a-Η)-Cis-N-Methyl-2,3,4,4a,9,9a-Hexahydro-1h- Carbazole]Chromium(0), Nigam Rath, F. Christopher Pigge, Shiyue Fang Dec 1997

Exo- And Endo-Tricarbonyl[(4b,5,6,7,8,8a-Η)-Cis-N-Methyl-2,3,4,4a,9,9a-Hexahydro-1h- Carbazole]Chromium(0), Nigam Rath, F. Christopher Pigge, Shiyue Fang

Nigam Rath

Acid-mediated hydride reduction of tricarbonyl([eta]6-N-methyl-1,2,3,4-tetrahydrocarbazole)chromium(0) affords either the cis-fused exo-hexahydrocarbazole chromium(0) complex {[Cr(C13H17N)(CO)3], (I)} exclusively, or a separable mixture of (I) and the endo-isomer {[Cr(C13H17N)(CO)3], (II)}, depending upon the choice of hydride donor. The conformations of the hexahydrocarbazole systems differ in the orientation of the indoline moiety with respect to the saturated hexahydrocarbazole rings. The isolation of the exo isomer is unusual, as this complex arises via reaction at the sterically more hindered endo face of the coordinated ligand.