Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on July 25, 2008). Includes bibliographical references (p. 22-24).

Thesis (Ph. D.)--Johns Hopkins University, 1914. / Biography.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [94]-106).

Thesis (Ph. D.)--Columbia University, 1929. / Vita.

Thesis (Ph. D.)--Johns Hopkins University, 1914. / Biography.

The mechanism of the permanganate oxidation of benzylamine and benzylamine-α-d₂ has been investigated in the pH region 2 to 14. The deuterium isotope effect, kH/kD, was found to be 7-0 from pH 8 to 10.7. The absence of salt effects and the observation that the oxidation rate followed the ionization process of the benzylammonium ion show that benzylamine is oxidized via the neutral molecule. Beyond pH 12 the rate of oxidation was found to be directly proportional to the hydroxyl ion concentration. A study of 11 meta- and para-substituted benzylamines shows excellent Hammett correlation with σ+ for 8 of the compounds, with the p-nitro, m-nitro, and m-trifluoromethyl derivatives deviating considerably from the Hammett plot. ρ+ was -0.28. The correlation with σ+ and the very negative ΔS≠ values obtained for the oxidation reaction show that the transition state must be an ionic one involving extensive charge separation. The rate-determining step is consistent with hydrogen transfer from benzylamine to permanganate but the choice of a hydride ion transfer mechanism or a hydrogen atom transfer mechanism cannot be unequivocally made from the results obtained in this thesis. For the oxidations in the highly alkaline regions beyond pH 12, termolecular mechanisms are suggested. Whereas O-alkylation protects alcohols from oxidation by permanganate, N-alkylation greatly increases the oxidation rate of amines. However, N-acylation tends to protect the amine from oxidation. Limited studies of the kinetics of permanganate oxidation of ammonia, cyclohexylamine, N,N-dimethylbenzylamine, and (-)- α-methylbenzylamine were carried out to compare their rates of oxidation with those for benzylamine. The mechanism of the permanganate oxidation of t-butyl -amine to t-nitrobutane was studied from pH 8 to 12. As in the benzylamine oxidation t-butylamine is oxidized via its neutral molecule. The absence of an α-hydrogen and the absence of a substantial isotope effect in t-butylamine-ND₂ suggest that the mechanism involves an oxidative attack on the nitrogen by permanganate. The formation of a quaternary hydroxylamine derivative between t-butylamine and permanganate has been proposed for the rate-determining step. The kinetics of permanganate oxidation of benzylamines at -10° in frozen H₂O and D₂O has been investigated from pH 7.5 to 9.3. The reaction order remains unchanged from that at 25°. The rates of oxidation are more than 10 times greater in ice at -10° than in liquid water at -10°, and this acceleration increases with decreasing pH. For p-nitrobenzylamine there is only a 3-fold increase in rate in going from liquid to frozen water at -10°. An apparent pKBH+ of 8.70 was obtained for benzylamine at -10° in ice. No change in the rate was observed when the oxidation was carried out in frozen D₂O and when the ionic strength of the medium was increased. The accelerating effects observed in the frozen systems are discussed in terms of pH, concentrating effect of the freezing, and the orientating effect of the ice structure. / Science, Faculty of / Chemistry, Department of / Graduate

The kinetics of the oxidation of formic acid by permanganate in aqueous perchloric acid solution, i.e., 2MnO¯₄ + 3HCOOH + 2H⁺ → 2MnO₂ + 3CO₂ + 4H₂O were studied in the temperature range 15 to 35°C. The variables examined included the reactant and hydrogen ion concentrations, ionic strength, the presence of various metal ions, and solvent and reactant deuterium isotope effects. The reaction appears to proceed through two independent paths in which the rate-determining steps are bimolecular reactions of permanganate with formic acid and with formate ion, respectively. The kinetics are thus of the form -d [MnO₄¯] / dt = [M nO₄¯] [HCOOH] (kA + kBKi / [H⁺] ) where kA and kg are rate constants of the two bimolecular reactions involving formic acid and formate ion, respectively, and Ki is the ionization constant of formic acid. The Arrhenius expressions for the rate constants were found to be kA = 1.1 x 10⁹exp. (-16400/RT) 1.mole¯¹sec¯¹ and kB = 7.8 x 10⁹exp. (-13000/RT) 1.mole¯¹sec¯¹. The formate ion reaction exhibits a large deuterium (HCOO¯:DCOO¯) isotope effect which suggests cleavage of the C-H bond in the rate-determining step. The absence of a corresponding isotope effect in the formic acid reaction suggests that it proceeds by a different mechanism. Fe⁺⁺⁺(but not Ag⁺, Cu⁺⁺, Co⁺⁺ or Na⁺) was found to catalyze the reaction, possibly by a mechanism involving a FeMnO₄⁺⁺ complex. Previous investigations of the formic acid-permanganate system have been confined to lower acidities than the present one, and only the formate ion contribution to the reaction had been detected. / Science, Faculty of / Chemistry, Department of / Graduate

In order to study the possible effects on permanganate oxidation reactions of a carboxyl sustituent near the reacting centre, three systems were investigated. The first of these systems consisted of the 2-and 4-benzhydrolcarboxylic acids. It was found that the 2-compound reacted more slowly than the 4-compound. The activation parameters at pH 5.45 show that the rate difference is accounted for entirely in terms of the difference in entropy of activation between the two compounds. Solubility difficulties prevented a study of the reaction below about pH 5. The kinetic results in more basic solution indicate that the pK corresponding to alcoholic OH ionization is greater for the 2-isomer than the 4-isomer. This behaviour is readily explained by examining the pK’s of several model compounds. The second system consisted of phthalaldehydic acid and terephthalaldehydic acid. The behaviour expected for aldehydes is observed except for phthalaldehydic acid at pH 1.55. The kinetic results for phthalaldehydic acid suggest rather strongly that it exists as 3-hydroxy- phthalide in acid solution (pH 1.55) and as the free aldehyde above pH 6. This result is shown to be in accord with previous work dealing with the diverse chemical behaviour of phthalaldehydic acid. The third system was the 2-carboxy cyclohexanol system. The pH-rate profiles of a number of isomeric 2-carboxy cyclohexanols were investigated as well as-that of the parent compound, cyclohexanol. It was found that cis-2-hydroxy-cyclohexanecarboxylic acid (XIV) showed a bell-shape rate maximum in its pH-rate profile around pH 6, while trans-2-hydroxycyclohexanecarboxylic acid did not. The parent compound, cyclohexanol, does not show such an effect - the pH-rate profile is almost flat in the region pH 4 to 8. The pH-rate profiles of cis-5-t-butyl-cis-2-hydroxycyclohexanecarboxylic acid (X), cis-5-t-butyl-trans-2- hydroxycyclohexanecarboxylic acid (XI), and trans-5-t-butyl-cis-2-hydroxycyclohexanecarboxylic acid (XII) were also investigated. A mechanism is proposed which involves two opposed dissociation equilibria involving hydrogen ions. A comparison of the reactivity of XIV in protium oxide with that in deuterium oxide gives evidence consistent with the mechanism. The conformational aspects of the reaction (elucidated by means of the conformationally biased compounds -X, XI and XII) were found also to be consistent with the proposed mechanism. It was possible to make a decision between the two kinetically indistinguishable forms of the proposed mechanism on the basis of the assembled data / Science, Faculty of / Chemistry, Department of / Graduate

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