Physical Sciences and Mathematics Commons^™

Iupac 32nd International Congress On Macromolecules "Macro 88", Otto Vogl, Naohuki Koide, Tatsuki Kitayama, Koichi Hatada

Emeritus Faculty Author Gallery

No abstract provided.

Substituent Effects On The Gas-Phase Acidity Of Silane, Mark S. Gordon, David E. Volk, David R. Gano

Mark S. Gordon

In a previous paper, the gas-phase acidities of XHn compounds (X= C, N, 0, F, Si, P, S, Cl) were predicted with ab initio wave functions. At the MP4 level of theory with extended basis sets (6-311++G(3df,2pd)3 for second-period atoms and 6-3l++G- (3df,2pd) for third-period atoms], the calculated gas-phase acidities for these species were determined to be within 2 kcaljmol of experimental values. Similar results for the second period were obtained by DeFrees and McLean.

Iupac 32nd International Congress On Macromolecules "Macro 88", Otto Vogl, Naohuki Koide, Tatsuki Kitayama, Koichi Hatada

Otto Vogl

No abstract provided.

Air Oxidation Of A Soluble Coal Extract, Douglas Kimbler

Masters Theses & Specialist Projects

The effects of air oxidation on coal may change many important attributes of the coal such as calorific values, solubilities and solvent swelling values. By studying the effects of air oxidation on the soluble portion of coal, we were able to study coal oxidation in a new light.

Stepwise Synthesis And Structural Characterization Of The Molybdenum-Iron-Sulfur {[Mofe3s4cl2(Cl4cat)]2(.Mu.2-S)2}6- And {[Mofe3s4cl2(Cl4cat)]2(.Mu.2-S)(.Mu.2-Oh}5- Doubly Bridged Double Cubanes Obtained By The Coupling Of [Mofe3s4] Clusters, Dimitri Coucouvanis, Paul Challen, Sang Koo, W. Davis, W. Butler, W. Dunham

Paul R. Challen

No abstract provided.

Angular-Momentum-Bearing Modes In Fission, Luciano G. Moretto, Graham F. Peaslee, Gordon J. Wozniak

Faculty Publications

The angular-momentum-bearing degrees of freedom involved in the fission process are identified and their influence on experimental observables is discussed. The excitation of these modes is treated in the “thermal” limit and the resulting distributions of observables are calculated. Experiments demonstrating the role of these modes are presented and discussed.

Ua66/7/2 Hilltopper News, Wku Chemistry

WKU Archives Records

Newsletter created by and about the WKU Chemistry department.

Determination Of The Thermal Stability Of Perfluoroalkylethers By Tensimetry: Instrumentation And Procedure, Larry S. Helmick, William R. Jones

Science and Mathematics Faculty Publications

A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (Td) of perfluoroalkylethers have been developed and tested. Both the I+ m apparatus and the procedure are described in detail. Results of QU) testing with bis(2-ethylhexyl) phthlalate and trimethylolpropane wI triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The Td obtained for each compound at a gas volume/heated liquid volume ratio of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene …

Identification And Quantitation Of Volatile Amines In Marine Sediments, Chuen Mei Huang

Chemistry & Biochemistry Theses & Dissertations

Pore waters which were taken from sediments of the Chesapeake Bay were analyzed to determine the presence of volatile amines. A purge-and-trap technique was used to concentrate the amines. Then, following derivatization with heptaflourobutyric anhydride, the HFBA-amines were analyzed by gas chromatography with electron capture detection and with mass spectrometric detection. One secondary amine, diethylamine with a concentration of 0.3-0.6 uM, was found in a total of three pore water samples from cores collected on two different dates. A primary amine, sec-butylamine with a concentration of O. 05 AIM, was also found in one of these same samples. Another primary …

Study Of Acetone Extractable Organic Matter From Airborne Particulate Matter From An Urban Site, Wenhui Wu

Theses

Two seasonal periods (Winter 1988; Summer 1988) of daily Newark urban air samples were collected on glass fiber filters. Each filter was first extracted with dichloromethane and subsequently with acetone. Quarterly composites of each were then tested for mutagenicity. The results of the analysis of the less polar dichloromethane extracts were reported in the thesis of Junghen Lwo. A modified fractionation scheme involving acid-base partitioning and silica gel column chromatography has been used as the first step in the bioassay-directed search for significant levels of mutagenic compounds in extracts of inhalable (IP 10) ambient air particulates. The biologically "hot" fractions …

Semiempirical Determination Of Intermolecular Anharmonicity In Molecular Crystals: The Case Of 1,2,4,5-Tetrabromobenzene, R.C. Dye, Craig J. Eckhardt

Craig J. Eckhardt Publications

The molecular crystal 1,2,4,5-tetrabromobenzene (TBB) has been studied using Brillouin scattering and lattice dynamical calculations. A method for mapping acoustic mode anharmonicity is developed that exhibits substantial directional behavior and correlates well with the directions of the molecular movements associated with the phase transition. It is shown that by comparing the calculated sound velocities with the experimental values, insight can be gained into the displacive phase transition and the lattice dynamics of TBB. The sound velocities are plotted for three crystallographic planes containing the crystal axes. The relationships between sound velocities and lattice dynamics are discussed. The phonon dispersion curves …

Uv Multiphoton Induced Chemistry Of Nitrobenzene In Solution, Joseph J. Belbruno, Gary Siuzdak, Simon North

Dartmouth Scholarship

The technique of Multiphoton Induced Chemistry (MPIC) has been employed to initiate ion-molecule chemistry of organic molecules in solution. We report one of the first examples of the use of liquid phase multiphoton ionization (MPI) to prepare organic cations, which then react with the solvent in ionmolecule processes. The products obtained in this chemical sequence are significantly different from those observed in conventional or multiphoton-induced neutral chemistry in the same solvent. The particular example explored in this work is the reactivity of the nitrobenzene cation in methanol solvent. Products of the ion-molecule chemistry, detected by gas chromatography/mass spectrometry, are phenol …

Quantitative Footprinting Analysis. Binding To A Single Site, Robert Rehfuss, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

The theory for measuring ligand binding constants from footprinting autoradiographic data associated with a single binding site is derived. If the ligand and DNA cleavage agent compete for a common site, the spot intensities are not proportional to the amount of DNA not blocked by ligand. The analysis of a single site is experimentally illustrated by using results for the anticancer drug actinomycin D interacting with the duplex d(TAGCGCTA)2 as probed with the hydrolytic enzyme DNase I.

Light Scattering Apparatus For Angular Dependent Studies Of Anisotropic Materials, R.C. Dye, J. Sartwell, Craig J. Eckhardt

Craig J. Eckhardt Publications

An improved method for light scattering from acoustic phonons in small, low-symmetry solids is described. This instrumentation greatly facilitates the determination of elastic constants in highly anisotropic materials. Elastic scattering can be greatly reduced so that weaker phonon modes can be observed. Errors associated with the determination of the polarization directions of an anisotropic material are minimized by considering crystal optics. Review of Scientific Instruments is copyrighted by The American Institute of Physics.

Predicted Heats Of Formation For Methylsilylene And Dimethylsilylene, Mark S. Gordon, Jarry A. Boatz

Mark S. Gordon

Ab initio calculations at the MP216-31G(d,p) level of computation, combined with a sequence of isodesmic reactions, have been used to predict the heats of formation of methylsilylene and dimethylsilylene to be 49.2 and 32-33 kcallmol, respectively. These results are discussed in the light of recent experimental determinations in the accompanying experimental papers.

Photocycloaddition Of 4,5',8-Trimethylpsoralen And Oleic-Acid Methyl-Ester - Product Structures And Reaction-Mechanism, Kathleen G. Specht, W. Robert Midden, Miles R. Chedekel

Chemistry Faculty Publications

The stereochemical structures of the four adducts formed between oleic acid methyl ester (OAME) and 4,5',8-trimethylpsoralen (tmPso) have been determined. Assignment of the tmPso 'H NMR spectrum was accomplished by analogy to two coumarin model compounds and with the use of homonuclear decoupling and resonance enhancement. Assignment of the lH NMR spectra for the OAME-tmPso adducts was made by analogy to the spectra of OAME and tmPso and using 2D &resolved and COSY analyses. The configurations of the cyclobutyl rings in these adducts was determined by The stereochemical structures of the four adducts formed between oleic acid methyl ester (OAME) …

Thermogravimetric Analysis Of Coal Blends Under Conditions Of Pyrolysis & Combustion, Yaodong Gan

Masters Theses & Specialist Projects

In recent years, the growing attention to coal quality by coal-burning utilities has led to an increase in coal blending. Coal blending is done with both economics and the quality of coal in mind. To assess the quality of coal, pyrolysis and combustion influencing thermal parameters, as measured in thermogravimetric analysis (TGA) experiments can be applied. The coal industry needs a study to determine relationships that may exist between the measured values of TGA thermal parameters in individual coals and those in the blends. The TGA thermal parameters are the weight loss, T_max, T_i, T_{1/2 …}

Finite Temperature Effects In Na3+ And Na3: A Path Integral Monte Carlo Study, Randall W. Hall

Randall W. Hall

31st Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and registration information for the 31st annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 30 - August 4, 1989.

Structures Of Two Organosilyl Azides, Steven S. Zigler, Kenneth J. Haller, Robert West, Mark S. Gordon

Mark S. Gordon

X-ray crystal structures were determined for trimesitylazidosilane (3) and 1,1-dimesityl-2,2-diphenyl- 2-tert-butylazidodisilane (4). The NcN2 and N2-N3 bond lengths (pm) in both compounds are nearly equal, being 115.8 and 117.0 for 3 and 117.0 and 114.7 for 4, respectively. These silyl azides thus differ markedly from organic azides, in which N2-N3 is much shorter than NcN2• Molecular orbital calculations predict N2-N3 to be 6 pm shorter than NcN2 in H3SiN3 (5). The N-N-N angle is 173.7° for 3 and 174.9° for 4, in good agreement with the calculated value for 5.

Intrinsic Frequency Analysis Of The Generalized Normal-Mode Vibrations For The Reaction H 2 + Ch3 - H + Ch4, Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

Vibrational energy distributions and intrinsic frequencies are computed at selected points along the H 2 + CH 3 - H + CH4 intrinsic reaction coordinate, calculated at the UHF /ST0-3G level. The energy distributions and intrinsic frequencies are shown to provide a clear and intuitively pleasing picture of the evolution of generalized normal coordinates along the reaction path. Furthermore, these quantities aid in the identification of avoided crossings between distinct generalized normal modes and between generalized normal modes and the reaction coordinate.

A Study Of The Flammability Of Chlorinated Polyethylene By Thermal Analysis, Michele Whitely

Masters Theses & Specialist Projects

High Density Polyethylene (HDPE) is a highly flammable compound. Finding a method to reduce HDPE's flammability is of great scientific interest to researchers and industry. Chlorination of the HDPE has been shown to have an effect on the flammability of the polymer. This study looks at the effects of various chlorinated samples on the thermal decomposition of HDPE in atmospheres of nitrogen, air, and oxygen. The thermal analysis instruments used were a Thermogravimetric Analyzer (TGA), and a Differential Scanning Calorimeter (DSC). To study the gaseous products evolved during thermal decomposition of the polymer Fourier Transform Infrared Spectrophotometry (FTIR) and Gas …

Mounting Sex Pheromone: A Novel Pheromone Responsible For Mate Recognition In The Ixodidae, Jgc Hamilton

Theses and Dissertations in Biomedical Sciences

Cholesterol oleate was demonstrated to be the cuticular contact sex pheromone of Dermacentor variabilis. This pheromone which has been termed the Mounting Sex Pheromone (MSP) was also demonstrated to be present on the surface of D. andersoni, Amblyomma maculatum and A. americanum. This contact sex pheromone enables males excited and attracted by 2,6-dichlorophenol to identify the female as a potential mating partner. The MSP is the second in the series of three sex pheromones guiding the hierarchy of behavioral responses which constitute tick courtship behavior. Tests with D. variabilis and D. andersoni showed that this pheromone …

Simultaneous Determination Of 3-Methoxy-4-Hydroxyphenyl-Glycol, Homovanillic Acid, And 5-Hydroxyindoleacetic Acid In Plasma By High Performance Liquid Chromatography, Yung-Te Tseng

Chemistry & Biochemistry Theses & Dissertations

A rapid, reliable, and sensitive method for simultaneous determination of 3-methoxy-4-hydroxyphenylglycol (MHPG), Homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5- HIAA) in plasma is described. The method is based on high performance liquid chromatography with electrochemical detection. Samples were filtered with Amicon Centrifree micropartition systems and extracted with organic solvent before chromatography. Chromatographic separation of sample components was achieved isocratically in a C18 reverse-phase column. Quantitation was performed by measuring the peak height ratios of the sample components to an internal standard. Analytical recoveries ranged from 50.78 (SD 4.2%) to 67.94 (SD 3.28). Within-run coefficient of variations (CVs) ranged from 3.78 …

Infrared Spectroelectrochemical Measurements Of The Electrochemical Double Layer: Using Carbon Monoxide As A Double Layer Probe Molecule, Mark Anderson, Andrea Russell, Stanley Pons

Mark R. Anderson

No abstract is currently available.

A Comparison Of Path Integral And Density Functional Techniques In A Model Two Electron System, Randall W. Hall

Randall W. Hall

Ab Initio Reaction Paths And Direct Dynamics Calculations, Kim K. Baldridge, Mark S. Gordon, Rozeanne Steckler, Donald G. Truhlar

Mark S. Gordon

A detailed study of methods for generating the minimum energy path of a chemical reaction using ab initio electronic structure calculations is presented; the convergence with respect to step size of the geometry and energy along this path is studied with several algorithms. The investigations are extended to the calculation of chemical reaction rate coefficients by interfacing the POLYRATE code for variational transition-state theory and semiclassical tunneling calculations with a locally modified GAUSSIAN82 electronic structure package that now contains reaction path following capabilities at both the Hartree-Fock and perturbation theory levels. This combined package is used to study the kinetics …

The Synthesis And Characterization Of Two All-Aliphatic Sterically Hindered Diesters Of Alpha, Alpha, Alpha', Alpha'-Tetramethyladipic Acid, Ronald L. Willson

Honors Theses

The bis-t-butyl- and bis-neopentyl glycol- diesters of α, α, α', α'-tetramethyladipic acid were synthesized via their diacid chlorides. α, α, α', α'-Tetramethyladipic acid was first prepared by a free radical coupling reaction of pivalic acid because it is not commercially available. The products of all syntheses were characterized by NMR and infrared spectra.

Determination Of The Kinetic And Thermodynamic Properties Of Bisulfite Addition To 4-Nitrocinnamaldehyde And 4-Dimethylaminocinnamaldehyde, Lisa Renee Nicosia

Honors Theses

The objective of this study is to compare the kinetic and thermodynamic properties of bisulfite additions to trans-cinnamaldehyde and two trans-cinnamaldehyde derivatives in order to examine substituent effects on these properties. The equilibrium constants at pH 4.63 and at 25C of two para substituted derivatives were determined using a spectrophotometric technique. The equilibrium constants were determined to be 299M-1 and 1340M-1 for 4-dimethylaminocinnamaldehyde and 4-nitrocinnamaldehyde respectively. Equilibrium constants were also determined at various temperatures, and changes in enthalpy and entropy were calculated to be: -39KJ/mol and -84J/molK for 4-dimethylaminocinnamaldehyde and -18KJ/mol and KJ/molK for 4-nitrocinnamaldehyde. The forward rate constants were …

C13- And H-Nmr Studies Of The Bisulfite Addition Products Of Simple Carbonyl Compounds, Diane A. Piasecki

Honors Theses

No abstract provided.