Chemistry Commons^™

Photochemical Studies Of Hydroxo-Bridged Complexes Of Chromium (Iii), Ronald Raymond Ruminski

Chemistry and Chemical Biology ETDs

The acid solution and solid state photolysis in both visible and ultraviolet regions of the spectrum for µ-hydro­xo-bis[pentaamminechromium(III)] chloride, and the solution photolysis in the visible and 1 traviolet region of the spectrum for µ-hydroxo-bis[pentaarnrninechr rnium(III)] perchlorate, have been studied. The ultraviolet irradiation of µ-hydroxo-bis[pentaamminechromium(III)] chloride in HCl and CHlO₄ produces a redox photoproduct identified as HCrO₄^-, although the rate of production of HCrO₄^- in HClO₄ is slower than in HCl. Photochemical cleavage of the hydroxo-bridge occurs in the ultraviolet photolysis of µ -hydroxo-bis[pentaanuninechromium(III)] chloride and is 1.9 times faster than the corresponding …

The Effects Of Various Pyrolysis Conditions On The Release Of Products From Green River Oil Shale, Georgia Thomas Fritz

Chemistry and Chemical Biology ETDs

The fusion of oil shales with eutectic mixtures of inorganic salts was studied with the objective of finding a chemical means of releasing the organic material either at a lower temperature or with a lower empirical activation energy (E_a). Experimental techniques by which the pyrolysis of oil shale was studied were thermogravimetry (TG), evolved gas detection (EGD), and pyrolysis/thin-layer chromatography (TLC). The following fused salts were investigated (ratios in mo1%): LiCO₃/Na₂co₃/K2CO3, 43.5/31.5/25.0; KSCN/NaSCN, 73.75/26.25; KSCN/­NaSCN, 70/30; Na₂SO₄/K₂SO₄/ZnSO₄, 29.1/30.2/40.7; NaCl/Na₂CO_{3 …}

Comparisons Between Oriented Film And Solution Tertiary Structure Of Various Nucleic Acids, Douglas R. C. Priore

Chemistry and Chemical Biology ETDs

It was desired to help establish whether or not the tertiary structure of a biomolecule is the same in a cry­stal (or an oriented film) as it is in solution. Generally it is accepted that the structures in these diverse environ­ments are similar, if not identical. By comparing the extinction coefficients obtained from oriented film data to those obtained from solution data it was hoped that this question might further be resolved. To this end an electric dichroism instrument built in our lab was used to measure the dichroic signal so as to calculate, with the help of the ultraviolet …

Infrared-To-Visible Upconversion In Rare Earth Doped Materials, Deon G. Ettinger

Chemistry and Chemical Biology ETDs

Upconversion materials have been prepared which may be stimulated by incident 970 nm radiation to emit in the visible region. The couples Yb⁺³-Ho⁺³ in a YF₃ host and Yb⁺³-Er⁺³ in YF₃, YPO₄, Li₃PO₄ and Y₂O₂S hosts have been studied at temperatures from 9K to 273K. For (Y_.80Yb_.19Er_.01)F₃ emission bands at 657 nm, 538 nm, 520 nm, 409 nm and 379 nm have been detected and determined to result from 3-, 2-, 2-, 3-, and 3-photon …

Conversion Of Farnesyl Pyrophosphate And Squalene To Sterols By Rat Liver Microsomal Enzymes: Specificity Of Sterol Carrier Protein₁, Kathleen Lobaugh Gavey

Chemistry and Chemical Biology ETDs

The conversion of farnesyl pyrophosphate to squalene by rat liver microsomes was investigated. The enzyme exhibited an apparent maximum velocity at a substrate concentration of 30 μM. No evidence of substrate inhibition was seen at concentrations up to 65 μM. Phosphatases present in the microsomes or in the 105,000 x g supernatant (S105) did not interfere with squalene synthesis under the experimental conditions used.

s₁₀₅ slightly enhanced the biosynthesis of squalene at the lowest concentrations of microsomal protein studied. The effect was reversed at higher concentrations of microsomes. A 1O-fold increase in the concentration of s₁₀₅ did not …

Charge Transfer Photochemistry Of Some Chromium (Iii) Complexes, Yohn Sik Kang

Chemistry and Chemical Biology ETDs

The photolyses of a series of chromium(III) complexes Cr(en)3 3+, Cr(den)2 3+, Cr(tn)3 3+, and Cr(pn)3 3+, where en= ethylenediamine, den= diethylenetriamine, tn = trimethylenediamine, and pn = propylenediamine, have been investigated. Experiments were carried out on unbuffered and buffered (pH= 2.00) solutions containing 10^-3 – 10^-2 M chromium(III) complexes at room temperature and 10°C. While purging with argon or oxygen, the irradiation was performed with 184.9-253.7 nm u.v. light, corresponding to the charge transfer bands of the complex.

Chromium(Iii) Tartrates, Gerald Lynn Robbins

Chemistry and Chemical Biology ETDs

The binuclear tartrate-bridged complexes [Cr₂ (tartH)₂ (L)₂] and Na[Cr₂ (tart) (tartH) (L)₂]("tart" = C₄H₂O₆^4-, "tartH" = C₄H₃O₆^3- and "L"= 1,10-phenanthroline or 2,2'-bipyridyl) have been synthesized where each complex contains either two optically active or two meso bridging ligands. A discussion of the number of isomers and symmetries of these complexes is presented, as well as a complete description of the syntheses of the complexes and their sodium salts. Steric constraints force the octahedral coordination geometry for the dimer containing two …

Reactions Of N-Ethoxycarbonylthioamides With Dinucleophilic Reagents, Babu George

Chemistry and Chemical Biology ETDs

When an N-ethoxycarbonylthioamide is treated with dinucleophilic reagents containing a primary or secondary amino group and another nucleophilic group, reaction occurs initially between the amino group of the reagent and the thiocarbonyl of the substrate with elimination of hydrogen sulfide and formation of a carbon, nitrogen double bond. The intermediate thus formed may subsequently cyclize in either of two different manners depending upon the relative positions of the two nucleophilic groups in the reagent. A. If the second nucleophilic group is adjacent to the amino group, or separated from it by one carbon atom, cyclization involves nucleophilic attack at the …

Syntheses Directed Toward The Construction Of 1-Deaza-1-Thialysergic Acid, Nicholas Richards Beller

Chemistry and Chemical Biology ETDs

With the goal of synthesizing 1-deaza-1-thialysergic acid (31), a series of substituted 2-stilbazole precursors of 31 was prepared.

313, R₁=SCH₃, R₂=H

314, R₁=SOCH₃, R₂=H

315, R₁=SO₂CH₃, R₂=H

173, R₁=H, R₂=COOC₂H₅

152, R₁ =SCH₃, R₂=COOC₂H₅

162, R₁=SOCH₃, R₂=COOC₂H₅

153, R₁=SO₂CH₃, R₂=COOC₂H₅

In connection with the synthesis …

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 …

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 …

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 …

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 …

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 …

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 …