Physical Chemistry Commons^™

Studies On Glyoxalase-I, Liang-Po Bebe Han

Chemistry and Chemical Biology ETDs

Glyoxalase-I has been purified 3000-fold from rat erythrocytes by a procedure employing chloroform-ethanol fractionation and chromatography on CM-Sephadex, Sephadex G100, and DEAE-Sephadex. Two major chromatographically distinct glyoxalase-I activity peaks (designated Form I and Form II) were resolved when a shallow linear salt gradient was used on a DEAE-Sephadex A50 column. Form I showed a specific activity of 861 I.U./mg protein and Form II showed a specific activity of 783 I.U./mg protein although neither was purified to homogeneity. Form I and Form II were distinguishable by disc polyacrylamide gel electrophoresis but indistinguishable kinetically. Rat erythrocyte glyoxalase-I was shown to be similar …

A Precipitation Model And Experimental Correlation With Various Properties Of Pentaerythritol Tetranitrate, Thomas Rivera

Chemistry and Chemical Biology ETDs

A continuous precipitation method for the preparation of crystalline pentaerythritol tetranitrate (PETN) has been developed. The process involves the precipitation of PETN from an acetone solution by the addition of water in a static mixer. The principal independent variable is the ratio, R, of the acetone-PETN solution flow rate to the flow rate of water.

A mathematical model based on dispersed plug-flow equations adequately represents the physical process. The relationships developed can be used to predict particle size distributions, two explosion properties of PETN, and estimate the effective kinetics involved in the precipitation process. The mass-weighted mean particle size, L, …

Rearrangements Of Stilbene And Derivatives Following Electron Impact, Gary Alan Braden

Chemistry and Chemical Biology ETDs

The electron impact generated mass spectra of ¹³C- labeled trans-stilbene, bibenzyl, trans-stilbene oxide, 1,2-dibromo-1,2-dyphenylethane, and tolan were studied. Scrambling of the molecular ion prior to fragmentation was examined, and the scrambling pattern occurring was determined wherever possible. Synthesis of 1,α’-¹³C₂-trans-stilbene was accomplished by strating with 1-¹³C- and 2-¹³C-acetic acid. 1,α’-¹³C₂-bibenzyl, starting with 1,α’-¹³C₂-trans-stilbene oxide, 1,α’-¹³C₂-l,2-dibromo-l,2-diphen­ylechane, and 1,α’-¹³C₂-tolan were all synthesized from the dilabeled stilbene. The mass spectral values for the phenyl ion, (pseudo)tropylium ion, (pseudo)phenylethyl …

Reactions Of 2-Aminopyridine With Picryl Halides, Betty Wright Harris

Chemistry and Chemical Biology ETDs

The purpose of this investigation was to study the reaction of 2-aminopyridine with picryl halides with the goal of providing evidence in support of a mechanism accounting for the formation of the observed products. Nuclear magnetic resonance spectroscopy was employed to measure the relative amounts of the various picryl protons in the product mixture, which were assumed to be proportional to the mole percent of the corresponding compounds. 2-Aminopyridine reacted with picryl chloride by a nucleophilic bimolecular substitution reaction to give 2-(N-picrylamino)pyridine as the major product; however, the major product of the reaction of 2-amino­pyridine with picryl fluoride is 1-picryl-2-(N-picrylimino)-1,2-dihydro­pyridine. …

Laser Pyrolysis Gas Chromatography And Plasma Stoichiometric Analysis, Ray Lorain Hanson

Chemistry and Chemical Biology ETDs

Normal-pulse laser interaction with organic solids was studied. Extensive interaction between the carrier gas and the plasma occurred in the quenching process. When hydrogen was used as the carrier gas, significantly greater quantities of products were detected from the laser pyrolysis of graphite and coal compared to laser pyrolysis in helium. Acetylene was shown to be the principal hydrocarbon product from plasma quenching. Equilibrium product distributions calculated at high temperatures by the minimization of free energy revealed that hydrogen and acetylene were the primary gaseous plasma quenching products for hydrocarbons. Organic solids with oxygen present in the molecule yielded carbon …

Composition And Structure Of A Stress Relieving Removable Epoxy Resin, Cecelia Victoria Krapcha Carter

Chemistry and Chemical Biology ETDs

The aqueous modification of polyol modified anhydride cured diglycidyl ether of bisphenol A exhibits properties of a brittle solid when subjected to an impulse stress, and properties of a viscous fluid when subjected to a steady state stress. This behavior is markedly different from the nonaqueous system. Early attempts to understand the nature of the change in properties and the physical mechanism involved have not been completely successful. These attempts have typically taken a physical chemistry approach and have not fully investigated the organic nature of the polymer. In order to fully understand a polymer system an important step should …

Properties Of Intercalated 2h-Nbse2, 4hb-Tas2 And 1t-Tas2, S. F. Meyer, R. E. Howard, G. R. Stewart, Juana Vivó Acrivos, T. H. Geballe

Faculty Publications, Chemistry

The layered compounds 2H-NbSe, 24Hb-TaS, 2and 1T-TaS2 have been intercalated with organic molecules; and the resulting crystal structure, heat capacity, conductivity, and superconductivity have been studied. The coordination in the disulfide layers was found to be unchanged in the product phase. Resistance minima appear and the superconducting transition temperature is reduced in the NbSe2 complex. Conversely, superconductivity is induced in the 4Hb-TaS2 complex. Corresponding evidence of a large change of the density of states, negative for 2H-NbSe2 and positive for 4Hb-TaS2, was also observed upon intercalation. The transport properties of all the intercalation complexes show a pronounced dependence upon the …

Properties Of Hxtas2, D. W. Murphy, F. J. Disalvo, G. W. Hull, J. V. Waszczak, S. F. Meyers, G. R. Stewart, S. Early, Juana Vivó Acrivos, T. H. Geballe

Faculty Publications, Chemistry

The preparation of Hx TaS2 (0 < x < 0.87) is described. The compounds are only marginally stable at room temperature, slowly evolving H2S and H2 (and possibly Hp in air). Magnetic susceptibility data show that a low temperature transformation in 2H ... TaS2 (at so•K) is suppressed with the addition of hydrogen, and· at the same time the superconducting transition temperature T c rises from 0.8 to ~4.2•K at x = 0.11. Heat capacity measurements near this concentration show the superconductivity to be a bulk effect. Finally, by correlation of this data with susceptibility and T c measurements in other intercalation compounds, we suggest that the rise of T c (at low electron transfer) is due to suppression of the low temperature transformation and not due to an excitonic mechanism of superconductivity.

Syntheses And Characterizations Of Vanadyl (Iv) Complexes With Dihydroxydicarboxylate Ligands, Sharon K. Hahs

Chemistry and Chemical Biology ETDs

Binuclear complexes of the vanadyl(IV) tartrates have already been shown to exist both in the solid state and in solution. These complexes consist of two vanadyl(IV) ions bridged by two tartrato(4-) ligands, either of the same--DD (or LL)-- or opposite--DL--enantiomeric configuration. (The meso isomer of tartaric acid will not form binuclear complexes with vanadyl(IV).) The DL complex is more stable than the DD complex due to a greater degree of staggering between the vicinal hydrogen atoms on each tartrate chain. Investigations of vanadyl(IV) complexes with substituted tartaric acid ligands--specifically, (±)-dimethyltartaric acid and (±)-threomethyltartaric acid--have been undertaken to determine whether this …

Electrochemical Investigations Of The Mechanisms Of Reduction Of Benzaldehyde Compounds In Sulfolane, Neal Russell Armstrong

Chemistry and Chemical Biology ETDs

The mechanisms of the reduction of benzaldehyde and several sub­stituted benzaldehydes in the dipolar, aprotic solvent sulfolane, have been investigated. A combination of cyclic voltammetry, transmission spectroelectrochemistry and ring-disk voltammetry was used in this study. Cyclic voltammetric studies indicated that the one-electron benz­aldehyde reduction was followed by a dimerization of the radical anion intermediate to the pinacol. The reduction peak potentials of the benzaldehydes were cathodically shifted in sulfolane compared to values obtained in aqueos media. This indicates an increase in the benzaldehyde reduction energy in the aprotic solvent. The rate of the following chemical reaction was also slower than …

Chronopotentiometric And Chronoamperometric Investigations Of Uranium (Vi) In Molten Condensed Phosphates, John J. Miglio

Chemistry and Chemical Biology ETDs

The diffusion coefficient, D, of U (VI) in molten sodium metaphosphate at 694°C was determined by two independent methods. D was also determined at R values of 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5, where R is the molar M₂O to P₂O₅ ratio and M is univalent. The relative amounts of various phosphate species present in the molten state were determined by thin layer chromatography after rapidly cooling the melt and dissolving the resultant glass in water. With the above information it was hoped to determine if D is inde­pendent of the experimental method of …

Synthesis Of Some N2-Alkyl- And Dialkylsubstituted 2'-Deozyguanosines, Carl D. Carter

Chemistry and Chemical Biology ETDs

Various N²-alkyl- and dialkylsubstituted 2’-deoxyguanosines have been synthesized. After future conversion into nucleotides, these compounds are to be used for incorporation into DNA. The modified DNA is expected to be useful in complexing studies with actinomycin. The presence of the 2-amino group in a purine has earlier been shown to be required for binding of actinomycin. Possible reasons for this requirement are an electronic effect or a precise steric fit involving hydrogen bonding. By comparing the relative stability of the complex formed between actinomycin and modified DNA versus actinomycin and normal DNA a better understanding of the mechanism …

The Synthesis And Reactivity Of Pyrrolopyridazines, Phillip Dan Cook

Chemistry and Chemical Biology ETDs

A new general synthetic sequence and cyclization method was developed which utilizes parts of both the Reissert and Madelung indole cyclization methods and leads to substituted pyrrolo[2,3-d]pyridazines,pyrrolo[3,2-c]-pyridazines, and pyrrolo[2,3-c]pyridazines. Thus, ethyl pyridazinylpyruvatel-oxides substituted with an ethyl formimidate or acetimidate group adjacent to the pyruvate group provides immediate precursors to pyrrolopyridazines. Mild acid hydrolysis of the acylimidate and subsequent cyclodehydration. Parallel to the latter stage of the Reissert indole cyclization method, affords ethyl pyrrolopyridazine carboxylates in high yields. On the other hand, treatment of the acylimidates with base provided ethyl pyrrolopyridazine glyxalates in high yields in a manner similar to the …

Solution Diffusion Coefficients -- New And Improved Methods For Their Determination, Newton C. Fawcett

Chemistry and Chemical Biology ETDs

The previously existing method of determining diffusion coefficients (D values) by diffusion from capillaries is critically reviewed. A differential error analysis of the method is given, and a formula is derived for the upper error bound on D as a function of capillary length, time span of the experiment, and ratio of final to initial diffusant concentrations. It is concluded that when the initial concentration and capillary length are not corrected for convective loss of diffusant solution from the capillary, the errors in concentration and length are additive and can significantly affect the accuracy of D. A new method (the …

The Synthesis Of Imidazo [4, 5-C] Pyridazines And Pyridazino-As-Triazines, Dennis King Chesney

Chemistry and Chemical Biology ETDs

The preparation of the first examples of imidazo[4, 5-c]­pyridazine-2, 7-dithiones is described herein. Several of the S-methyl and S-benzyl derivatives have been prepared and the conditions required for the selective monoalkylation of the 2, 7-dithione have been determined. Several new derivatives of imidazo[4, 5-c]pyridazine and imidazo[4, 5-c]pyridazine-2 or 7-thione are also described. The preparation of several examples of the previously unknown heterocyclic ring systems, 1, 2-dihydropyridazino[4, 5-c]­-as-triazine and 3, 4-dihydropyridazino[4, 3-e]-as-triazine, is described. The preparation, isolation, and structure determination of the products from the reaction of methylamine with 3, 4, 5-tri­chloropyridazine are described. It was found that the reaction of …

New Techniques In Precision Gamma Scanning: Application To Fast Breeder Reactor Fuel Pins, John R. Phillips

Chemistry and Chemical Biology ETDs

A new precision gamma scanning system is described. The system is designed for the thorough, detailed, nondestructive characterization of irradiated fast reactor fuel pins. Gamma scanning data are given for failed fuel pin , transfer mechanisms of fission products, quantitative isotopic scan­ning, and differential burnup profiles.

The system consists of a scanning mechanism for the precise positioning (±0.001 in.) of the irradiated fuel pin, high density tungsten alloy collimators for defining the volume segment from which the gamma-ray spectra are collected, a large high resolution an anticoincidence detector assembly for resolving complex gamma-ray spectra, and a computer con­trolled data acquisition …

The Synthesis Of Pyrimidines And Condensed Pyridazines As Potential Antimetabolites, Judith A. Wagner

Chemistry and Chemical Biology ETDs

Interest in the compounds described by this thesis was first aroused in the early 1930's when a research team began to investigate the mass poisonings of the population in Indonesia. The cause of the poisonings seemed to be the foodstuffs which the people made for themselves from the abundant coconut. Two products in particular, Bongkrek and Semaji, made from coconut presscakes and grated coconut, were apparently the source of the toxic substance. When made under improper conditions, the toxic principle developed in an otherwise harmless food product. A compound was finally isolated and established as the toxic principle by …

Computer Investigation Of The Variation Of Conductivity With Concentration, Larry Macpeers Shadwick

Masters Theses

Computer programs were developed tor the conductance equations of R. M. Fuoss and L. Onsager as well as for the conductance equations of T. J. Murphy and E. G. D. Cohen. These programs were used to calculate values from selected conductance measurements. The resulting values were compared with values produced by other computer programs using the equations of Fuoss and Onsager as well as the equations of E. Pitts. The comparisons demonstrated the equations of Murphy and Cohen to be the equal of or superior to the other equations for the majority of cases. The equations of Pitta were superior …

The Conductance Of Some Polyvalent Electrolytes, Jack Lee Worthington

Masters Theses

A new compound, 1,3,5-triphenylbenzene-4' ,4",4"'-trisulfonic acid, was synthesized by treating triphenylbenzene in 1,2-dichloroethane with chlorosulfonic acid. The reaction appears to be quantitative. Conductance measurements were then made on the sodium, potassium, and lanthanum salts of this new acid and of 1,3,5-benzenetrisulfonic acid.

The choice of these acids was based on two factors: 1) the desire to prepare a 3-3 symmetrical unassociated electrolyte which would allow the determination of a more reliable equivalent ionic conductance value for La³⁺ and 2) an interest in using the Murphy-Cohen equation to determine solute parameters such as association constants if association is present.

Conductance …

Acidities In Ethanol/Water Solvents: The Pka Of Hf, Raymond M. Merrill

Chemistry and Chemical Biology ETDs

The acidity of hydrofluoric acid in mixed ethanol/ water solvent systems was studied by determining the pKa of HF in a number of different ethanol concentrations. The effect of changing temperature on the acidity of HF in these media was also examined. The pKa's were determined using a lanthanum fluoride membrane Fluoride Specific Ion Electrode and a glass pH electrode versus the same reference electrode. The method eliminates the need to determine liquid junction potentials. By determining the pKa for HF in each ethanol/water mixture, at a number of different temperatures, thermodynamic parameters, such as free energy, enthalpy, entropy, and …

Synthesis Of Derivatives Of Pyrido [3,4-D]Pyridazines, Diane (D'Ottavio) Martin

Chemistry and Chemical Biology ETDs

The current interest in the biological activity of certain 1 ,4-disubstituted pyrido[2 ,3-d]pyridazines prompted the investigation of various derivatives of the isomeric pyrido[3,4-d]pyridazine ring system. Thus, 1,4 ­ dichloro[3,4-d]pyridazine was treated with thiourea and the intermediate thiouronium salt hydrolyzed to give pyrido[3, 4-d]pyridazine-1,4(2H,3H)-dithione which was subsequently alkylated to give 1,4-bis(alkylthio)pyrido­[3,4-d]pyridazines. On the other hand, 1,4-bis(arylthio)­pyrido[3,4-d]pyridazines were prepared by the reaction of 1,4-dichloropyrido[3,4-d]pyridazine with various substituted thiophenols. Furthermore, treatment of 1,4-dichloropyrido[3,4-d]­pyridazine with a variety of substituted anilines gave the corresponding 1,4-disubstituted aniline derivatives, whereas reaction with alkylamines afforded only the 1(4)-chloro-4(1)-alkylaminopyrido[3,4-d]pyridazines. When 1-chloropyrido[3,4-d]pyridazine-4(3H)-one or 4-chloropyrido[3,4-d]pyridazine-1(2H)-one was treated with hydrazine, the corresponding …

Acid-Base Titrations In Sulfolane, Francine O. Lawrence

Chemistry and Chemical Biology ETDs

A study of the solvent effects of sulfolane (tetrahydrothiophene 1, 1-dioxide, tetramethylene sulfone) upon a series of acids and several bases has been conducted. A procedure is presented for purifying sulfolane which results in a solvent of very low water content (5 x 10^-4 M) and very few impurities, as shown by its cooling curve. Potentiometric and conductometric measurements of additions of acids and bases to purified sulfolane and of various acid-base titrations were made. The series of carboxylic acids included benzoic, orthomethoxybenzoic, and three different monochlorobenzoic acids. The bases investigated included sodium methoxide, pyridine, and diphenylguanidine. Interpretation of …

Continuous Wave Co2 Laser Degradation And Mass Spectrometric Analysis Of Organic Polymers, Stanley G. Coloff

Chemistry and Chemical Biology ETDs

Previous laser-mass spectrometer and laser-gas-chromatographic instruments for study of organic polymer degradation have used high power pulsed lasers (ruby, Nd-glass) which limit sample characterization due to extensive fragmentation. A new experimental technique has been developed for high temperature pyrolysis and rapid analysis of organic polymers. The experimental technique combines a low power continuous wave CO₂ laser for sample pyrolysis and a time-of-flight mass spectrometer to analyze degradation products. The laser built for use in this study was a continuous flow CO₂ gas-molecular laser excited by high voltage direct current with maximum power of 10 watts at a wavelength …

Equilibrium And Kinetic Study Of The Substitution Reactions Of Pentacarbonylaminetungsten (O) With Triphenylphosphine, William O. Bailey

Masters Theses

A kinetic and equilibrium study of the reaction of triphenylphosphine (PPh₃) with pentacarbonylaminetungsten (O) [(CO)₅WNH₂C₆H₅] has been reported previously. Equilibrium constants for the reaction (CO)₅WNH₂C₆H₅ + PPh₃ = (CO)₅W[P(C₆H₅)₃] + C₆H₅NH₂ in toluene were reported to be 17.1, 49.2 and 65.7 respectively. In addition, the entropy change (ΔS) for the reaction was found to be 86±5 cal mol^-1 deg^-1.

In this study the above reaction was …

On The Mechanism Of The Diels-Alder Reaction--Dimerization Of Trans-Phenylbutadiene, Michael Ward Mcnicholas

Dissertations and Theses

The Diels-Alder dimerization of trans-1-substituted butadienes is expected to yield a cyclohexene adduct with the substituents in the 3 and 4 positions cis to one another. This prediction is based on past observations of other Diels-Alder additions. The cis-isomer is the only one consistent with a two-stage mechanism proposed by Woodward and Katz.

In the case of trans-phenylbutadiene, the expected adduct is cis-3-phenyl 1-4-(trans-styry1) cyclohexene. Alder, Haydn and Vogt, however, reported that the corresponding trans-isomer is the dimerization product. There is reason to believe that the observation of the trans-isomer may have been the result of product isomerization during purification. …

The Mechanism Of The Reaction Of Lead(Iv) Acetate, Thallium(Iii) Acetate And Mercury(Ii) Acetate With Ketones, Su Hsiung Tsung

Masters Theses

No abstract provided.

The Conductance Of Some Non-Rigid Bolaform Electrolytes, William Terry Schmidt

Masters Theses

Bolaform electrolytes are those which contain two or more charges separated by an inert framework. These are intermediate in structure between simple electrolytes and polyelectrolytes. Since these are similar to both synthetic and biological electrolytes, this investigation has been undertaken to determine some of their properties in solution.

The sodium and magnesium salts of ethane, propane, butane, pentane, hexane and decane α,ω-disulfonates were prepared. Each acid was prepared by refluxing the α,ω-dibromide of the desired salt with sodium sulfite. The sodium and magnesium salts were prepared by ion-exchange techniques.

The conductance of each salt was determined in methanol utilizing the …

A Kinetic Analysis Of The Iodination Of Pyruvic Acid And Pyruvate Esters, Mohamed M. Fahmi Hegazi

All Master's Theses

In the present work the relative rates of iodination of pyruvic acid and ethyl and methyl pyruvate have been compared at 25.0° C. These studies allow the determination of the respective free energies of activation for these processes. Measurements have also been carried out at various temperatures to determine the enthalpies and entropies of activation for the spontaneous and base catalysed iodinations of these pyruvate systems. The present thesis also includes a comparison of the solvent deuterium isotope effects associated with the spontaneous rate of iodination of pyruvic acid and the alkyl pyruvates. Also, the catalytic rate coefficients associated with …

Analytical Aspects Of Laser-Induced Degradation Of Organic And Inorganic Compounds, William T. Ristau

Chemistry and Chemical Biology ETDs

The rapid deposition of energy by means of a pulsed ruby laser to degrade organic and inorganic materials is investigated as an analytical tool. Advantages and disadvantages of using a laser are discussed and compared to current conventional pyrolysis methods. The interaction of laser radiation with matter is briefly discussed. A number of different organic compounds including saturated and aromatic hydrocarbons, heterocyclic compounds, and polymers have been studied. The degradation products were separated and identified by use of a gas chromatograph. Degradation studies have also been done on a series of inorganic salts including nitrates, sulfates, thiosulfates, and oxalates. The …

The Synthesis Of Some New Condensed Pyridazines, Pyridazine N-Oxides And Pyrimidines As Potential Chemotherapeutic Agents, Donald E. Pichler

Chemistry and Chemical Biology ETDs

The need for new antimicrobial and antifungal agents as well as medicinals possessing antiprotozoal activity against special strains of malaria resistant to most synthetic antimalarials prompted the synthesis of new compounds that may have the desired antimetabolite properties. The structural similarities of the 1,2,5-thiadiazolo[3,4-d] pyridazines and the v-triazolo[4,5-d]pyridazines with the biologically important purines prompted the synthesis of members of these ring systems. The 1,2,5-thiadiazoles synthesized as intermediates ware also screened as potential chemotherapeutic agents. Similarly, the pyridazine N-oxides and the 5-nitro substituted pyrimidines are structurally similar to the pyrazine N-oxides and the pyridine N-oxides, which are known to possess a …