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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 the …

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 of 10600 …

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 …

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 …