Chemistry Commons^™

2002 & 2003 Annual Meeting Extended Abstracts

Journal of the South Carolina Academy of Science

No abstract provided.

South Carolina Statewide Science Safety Project., Linda Sinclair, Jack Gerlovich, Rahul A. Parsa

Journal of the South Carolina Academy of Science

No abstract provided.

Some Notes On Multiplicative Congruential Random Number Generators With Mersenne Prime Modulus 261-1., James Harris

Journal of the South Carolina Academy of Science

No abstract provided.

Maternal And Sibling Influences On Seed Germination Of Aegilops Triuncialis Erin, Erin Scott, Andrew R. Dyer

Journal of the South Carolina Academy of Science

No abstract provided.

Scas Officers And Council Members 2003 - 2004

Journal of the South Carolina Academy of Science

No abstract provided.

Critical Thinking And Biology Instruction., David J. Stroup, John L. Frola

Journal of the South Carolina Academy of Science

No abstract provided.

Nitroalkane Anomaly: Computational Study With Cluster And Continuum Modeling, H. Yamataka, Salai Cheettu Ammal

Faculty Publications

The origin of anomalous relation between rates and equilibria for the proton-transfer reactions of nitroalkanes, known as nitroalkane anomaly, was investigated by theoretical calculations with a cluster model, in which three water molecules are explicitly considered in the system, as well as the PCM solvent continuum model. For the CH3NO2/CH3CH2NO2 system, B3LYP and MP2 computations reproduced the anomaly, and the imbalance in the charge distribution at the transition state (TS) was observed. In contrast, although the TS imbalance was detected for the substituted phenylnitromethane system, the Brønsted plots did not show any anomaly. The experimentally observed abnormally large Brønsted coefficient …

Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH₄CO–CH₄CO–CH₄ combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors.

A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification Of Proteins By Scavenging Carbonyl Intermediates Of Carbohydrate And Lipid Degradation, Paul A. Voziyan, Thomas O. Metz, John W. Baynes, Billy G. Hudson

Faculty Publications

Reactive carbonyl compounds are formed during autoxidation of carbohydrates and peroxidation of lipids. These compounds are intermediates in the formation of advanced glycation end products (AGE) and advanced lipoxidation end products (ALE) in tissue proteins during aging and in chronic disease. We studied the reaction of carbonyl compounds glyoxal (GO) and glycolaldehyde (GLA) with pyridoxamine (PM), a potent post-Amadori inhibitor of AGE formation in vitro and of development of renal and retinal pathology in diabetic animals. PM reacted rapidly with GO and GLA in neutral, aqueous buffer, forming a Schiff base intermediate that cyclized to a hemiaminal adduct by intramolecular …

“[Cu(Pyrazine-2-Carboxylate)2]2Cd4I8: Unprecedented 1-D Serpentine Chains And Regular 2-D Regular Metal-Organic Square Grids In A 3-D Framework., Delia M. Ciurtin, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

A novel three-dimensional coordination polymer containing
an unprecedented one-dimensional serpentine motif conjoined
with a two-dimensional square grid motif is presented.

Three Unique Coordination Geometries Involving 1,2-Dimethoxy-4,5-Bis(2-Pyridylethynyl)Benzene, Jeffrey E. Fiscus, Sandra Shotwell, Ralph C. Layland, Mark D. Smith, Hans Conrad Zur Loye, Uwe H. F. Bunz

Faculty Publications

Reaction of the new ligand 1,2-dimethoxy-4,5-bis(2-pyridylethynyl) benzene with different metal centers under similar reaction conditions led to three distinct structure formation processes: molecular ring closure, dimerization, and polymer formation.

Ca4Iro6, Ca3Mgiro6 And Ca3Zniro6, Matthew J. Davis, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

Single crystals of tetracalcium iridium hexaoxide, Ca₄IrO₆, tricalcium magnesium iridium hexaoxide, Ca₃MgIrO₆, and tricalcium zinc iridium hexaoxide, Ca₃ZnIrO₆, were prepared via high-temperature flux growth and structurally characterized by single-crystal X-ray diffraction. The three compounds are isostructural and adopt the K₄CdCl₆ structure type, comprised of chains of alternating face-shared [CaO₆], [MgO₆] or [ZnO₆] trigonal prisms and [IrO₆] octahedra, surrounded by columns of Ca²⁺ ions.

Formula: Ca₄IrO₆, Ca_3.34Mg_0.66IrO₆ and …

A Dipolar Coupling Based Strategy For Simultaneous Resonance Assignment And Structure Determination Of Protein Backbones, Fang Tian, Homayoun Valafar, James H. Prestegard

Faculty Publications

A new approach for simultaneous protein backbone resonance assignment and structure determination by NMR is introduced. This approach relies on recent advances in high-resolution NMR spectroscopy that allow observation of anisotropic interactions, such as dipolar couplings, from proteins partially aligned in field ordered media. Residual dipolar couplings are used for both geometric information and a filter in the assembly of residues in a sequential manner. Experimental data were collected in less than one week on a small redox protein, rubredoxin, that was 15N enriched but not enriched above 1% natural abundance in 13C. Given the acceleration possible with partial 13C …

Two Different One-Dimensional Structural Motifs In The Same Coordination Polymer: A Novel Interpenetration Of Infinite Ladders By Bundles Of Infinite Chains, Badruz Zaman, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

A coordination polymer with a novel structural motif
consisting of stacks of infinite ladders interpenetrated by
bundles of infinite chains is described; geometrical arguments
are made for the requirements that can lead to such
interpenetration as a function of ligand dimensions.

Crystal Growth, Structure Determination And Magnetism Of A New Hexagonal Rhodate: Ba9rh8o24, Katharine E. Stitzer, M. D. Smith, J. Darriet, Hans Conrad Zur Loye

Faculty Publications

Single crystals of Ba9Rh8O24, grown from a molten potassium carbonate flux, crystallize in the spacegroup R¯3c with lattice parameters of a = 10.0899(4) and c = 41.462(2) Å. Magnetic measurements on oriented single crystals reveal the existence of magnetic anisotropy

Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka

Faculty Publications

Through the use of variable disulfide crosslinkers, we have created polyacrylamide gels whose shape can be altered after polymerization. N,N'-bisacryloylcystamine is incorporated as a crosslinker, along with a smaller amount of a permanent crosslinker. After polymerization, the disulfide bonds are cleaved into thiols through reduction. By reoxidizing the thiols with the gel held in a new macroscopic shape, a new set of disulfide bonds is formed, and the gel is forced to adopt the new shape. Retension of the new shape improves with greater distortion from the original shape, as well as with increased concentration of variable …

Sr3Znpto6 And Sr3Cdpto6, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

The flux synthesis of single crystals of the isostructural compounds tristrontium zinc platinum hexaoxide, Sr₃ZnPtO₆, and tristrontium cadmium platinum hexaoxide, Sr₃CdPtO₆, is reported. The compounds adopt the pseudo-one-dimensional rhombohedral K₄CdCl₆ structure type, and feature chains of face-shared distorted ZnO₆ or CdO₆ trigonal prisms and PtO₆ octahedra, surrounded by columns of Sr²⁺ ions. All transition metals are located on the threefold axis of symmetry, while the Sr²⁺ cations lie on twofold axes.

Formula: Sr₃ZnPtO₆ and Sr₃CdPtO₆

Semiclassical Application Of The Mo”Ller Operators In Reactive Scattering, Sophya Garashchuk, John C. Light

Faculty Publications

Mo\ller operators in the formulation of reaction probabilities in terms of wave packet correlation functions allow us to define the wave packets in the interaction region rather than in the asymptotic region of the potential surface. We combine Mo\ller operators with the semiclassical propagator of Herman and Kluk. This does not involve further approximations and can be used with any initial value representation (IVR) semiclassical propagator. Time propagation in asymptotic regions of the potential due to Mo\ller operators reduces the oscillations of the propagator integrand and improves convergence of the results with respect to the number of trajectories. The effectiveness …

Self-Assembly Of A Bis-Urea Macrocycle Into A Columnar Nanotube, Linda S. Shimizu, Mark D. Smith, A. D. Hughes, Ken D. Shimizu

Faculty Publications

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns byX-ray crystallography.

Structure Determination Of Ba8Corh6O21, A New Member Of The 2h-Perovskite Related Oxides, Hans Conrad Zur Loye, M. D. Smith, K. E. Stitzer, A. El Abed, J. Darriet

Faculty Publications

Single crystals of Ba₈CoRh₆O₂₁ were grown out of a potassium carbonate flux. The structure was solved by a general method using the superspace group approach. The superspace group employed was R3m(00γ)0s with a = 10.0431(1) Å, c₁ = 2.5946(1) Å and c₂ = 4.5405(1) Å, V = 226.60(1) ų. Ba₈CoRh₆O₂₁ represents the first example of an m = 5, n = 3 member of the A_3n+3mA'_nB_3m+nO_9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six …

Simplified Calculation Of The Stability Matrix For Semiclassical Propagation, Sophya Garashchuk, John C. Light

Faculty Publications

We present a simple method of calculation of the stability (monodromy) matrix that enters the widely used semiclassical propagator of Herman and Kluk and almost all other semiclassical propagators. The method is based on the unitarity of classical propagation and does not involve any approximations. The number of auxiliary differential equations per trajectory scales linearly rather than quadratically with the system size. Just the first derivatives of the potential surface are needed. The method is illustrated on the collinear H[sub 3] system.

Effect Of Collagen Turnover On The Accumulation Of Advanced Glycation End Products, Nicole Verzijl, Jeroen Degroot, Suzanne R. Thorpe, Ruud A. Bank, J. Nikki Shaw, Timothy J. Lyons, Johannes Wj Bijlsma, Floris Pjg Lafeber, John W. Baynes, Johan M. Tekoppele

Faculty Publications

Collagen molecules in articular cartilage have an exceptionally long lifetime, which makes them susceptible to the accumulation of advanced glycation end products (AGEs). In fact, in comparison to other collagen-rich tissues, articular cartilage contains relatively high amounts of the AGE pentosidine. To test the hypothesis that this higher AGE accumulation is primarily the result of the slow turnover of cartilage collagen, AGE levels in cartilage and skin collagen were compared with the degree of racemization of aspartic acid (% D-Asp, a measure of the residence time of a protein). AGE (Ne- (carboxymethyl)lysine, Ne-(carboxyethyl)lysine, and pentosidine) and % D-Asp concentrations increased …

Pyridoxamine, An Inhibitor Of Advanced Glycation Reactions, Also Inhibits Advanced Lipoxidation Reactions: Mechanism Of Action Of Pyridoxamine, Joelle M. Onorato, Alicia J. Jenkins, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Maillard or browning reactions lead to formation of advanced glycation end products (AGEs) on protein and contribute to the increase in chemical modification of proteins during aging and in diabetes. AGE inhibitors such as aminoguanidine and pyridoxamine (PM) have proven effective in animal model and clinical studies as inhibitors of AGE formation and development of diabetic complications. We report here that PM also inhibits the chemical modification of proteins during lipid peroxidation (lipoxidation) reactions in vitro, and we show that it traps reactive intermediates formed during lipid peroxidation. In reactions of arachidonate with the model protein RNase, PM prevented modification …

Ac Susceptibility Of Sr3CuptXIr1-XO6: A Magnetic System With Competing Interactions And Dimensionality, S H. Irons, T D. Sangrey, K M. Beauchamp, M D. Smith, Hans Conrad Zur Loye

Faculty Publications

Sr₃CuPt_xIr_1-xO₆ has been cited as an example of a one-dimensional quantum spin chain with competing ferromagnetic and antiferromagnetic interactions. We have measured the ac susceptibility of Sr₃CuPt_xIr_1-xO₆ with x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7, in magnetic fields of 0–60 kOe, and at temperatures down to 0.275 K. Our data show that the x=endpoint Sr₃CuIrO₆, exhibits long-range ferromagnetic order at T=20.1 K, contrary to results from dc susceptibility studies which indicated that it remained a one-dimensional ferromagnet to below 4 …

Structural And Electrical Characterization Of A Novel Mixed Conductor: Ceo2 - Sm2O3 - Zro2 Solid Solution, W. Huang, P. Shuk, M. Greenblatt, M. Croft, Fanglin Chen, M. Liu

Faculty Publications

solid solutions were synthesized for the first time by the hydrothermal method. The electrical properties of the solid solutions have been studied in air and under reducing conditions. Solid solutions with the fluorite structure were formed in all of the studied range of substitution after calcination at 1500°C. With increasing substitution up to 30 mol %, the electronic conductivity increases under a reducing atmosphere. The solid solution has good mixed electronic and ionic conductivity; the total conductivity is 0.42 S/cm at and 700°C with an estimated ionic conductivity of ca. .

Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk

Faculty Publications

Calculation of chemical reaction rates lies at the very core of theoretical chemistry. The essential dynamical quantity which determines the reaction rate is the energy-dependent cumulative reaction probability, N(E), whose Boltzmann average gives the thermal rate constant, k(T). Converged quantum mechanical calculations of N(E) remain a challenge even for three- and four-atom systems, and a longstanding goal of theoreticians has been to calculate N(E) accurately and efficiently using semiclassical methods. In this article we present a variety of methods for achieving this goal, by combining semiclassical initial value …

Principal Component Mapping Applied To Raman Microspectroscopy Of Fiber-Reinforced Polymer Composites, C. M. Stellman, K. S. Booksh, A. R. Muroski, M. P. Nelson, Michael L. Myrick

Faculty Publications

We describe the development and implementation of a spectroscopic Raman imaging system using Principal Component data analysis. Raman microspectroscopy followed by multivariate data analysis and principal component mapping has been used to investigate the spatial variations of chemical and physical properties at interfaces in glass-reinforced composites on the micrometer scale. A protocol for monitoring chemical and physical variances via multivariate statistics has been developed and a preliminary study of a "real world" glass-reinforced composite is presented. It is demonstrated that multivariate Raman imaging is more precisely interpretable than traditional univariate methods and that by appropriately choosing distinct spectral regions (such …

Chemical Signals From Submarine Fluid Advection Onto The Continental Shelf, W. S. Moore, Timothy J. Shaw

Faculty Publications

No abstract provided.

Correlation Function Formulation For The State Selected Total Reaction Probability, Sophya Garashchuk, David J. Tannor

Faculty Publications

Investigates the correlation function formulation for the state selected total reaction probability. Discussion of the wave packet propagation; Derivation of the correlation function expression for the N[sub alpha](E); Application of quantum-mechanical and Herman-Kluk propagation methods.

Role Of The Maillard Reaction In Aging Of Tissue Proteins: Advanced Glycation End Product-Dependent Increase In Imidazolium Cross-Links In Human Lens Proteins, Elisabeth Brinkmann Frye, Thorsten P. Degenhardt, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Dicarbonyl compounds such as glyoxal and methylglyoxal are reactive dicarbonyl intermediates in the nonenzymatic browning and cross-linking of proteins during the Maillard reaction. We describe here the quantification of glyoxal and methylglyoxal-derived imidazolium cross-links in tissue proteins. The imidazolium salt cross-links, glyoxal-lysine dimer (GOLD) and methylglyoxal-lysine dimer (MOLD), were measured by liquid chromatography/mass spectrometry and were present in lens protein at concentrations of 0. 02-0.2 and 0.1-0.8 mmol/mol of lysine, respectively. The lens concentrations of GOLD and MOLD correlated significantly with one another and also increased with lens age. GOLD and MOLD were present at significantly higher concentrations than the …