Thesis (Ph. D.)--Lehigh University, 2005. / Includes bibliographical references and vita.

Thesis (Ph. D.)--University of Liverpool, 1977. / Includes bibliographical references (leaves 245-261).

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (p. 107-112).

No description available.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on month day year) Thesis advisor: Dr. M. Frederick Hawthorne, Dr. Michael Harmata. Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Rhode Island, 2006. / Includes bibliographical references (leaves 88-91).

The altered acidities of amino acid residues in folded proteins can be used as a good indication for the diverse functions, stabilities as well as folding-unfolding states of the proteins. Previously, our group has investigated the gas phase acidities of a series of cysteine containing peptides of four residues and longer. The results showed that the helix macrodipole might have a significant influence on the acidities of these peptides. In this work, the gas phase acidities of isomeric small cysteine containing di- and tri-peptides were investigated experimentally and computationally. The gas phase acidities (ΔacidG) and related thermochemical quantities (ΔacidH and ΔacidS) were determined by using the extended Cooks kinetic method. A triple-quadruple mass spectrometer interfaced with an electrospray ionization source was employed for the study. The gas phase acidities of the N-terminal cysteine peptides (CysAla1,2NH2 and CysGly1,2NH2) were determined to be in the range of 321-323 kcal/mol, and the acidities of the C-terminal cysteine peptides (Ala1,2CysNH2 and Gly1,2CysNH2) were around 327- 331 kcal/mol. The results showed that theN-cysteine peptides were more acidic than the corresponding C-cysteine peptides, tri-peptides were stronger acids than di-peptides, and the acidities of cysteine-polyglycine peptides were close to those of the cysteine-polyalanine analogues. Computational studies were performed through conformer search, geometry optimization, and energy calculations using the Spartan and the Gaussian suite of programs. The results showed that the low energy conformations of all deprotonated peptides were coils. The greater acidities of the N-cysteine peptides were likely due to the stronger hydrogen-bonding interactions in the deprotonated N-cysteine peptides, which efficiently stabilized the thiolate anions. The theoretically predicted acidities were in good agreements with the experimental results.

Thesis (Ph. D.)--School of Chemistry and Biochemistry, Georgia Institute of Technology, 2004. Directed by Charles L. Liotts. / Includes bibliographical references.

This thesis details the development and exploration of a catalytic carbonyl-olefin metathesis reaction. A catalytic transformation of this type has not been accomplished previously and stoichiometric processes were neither general nor desirable. A simple hydrazine catalyst was found to effect this reaction with the use of strained olefins. The development and optimization of this reaction, including the hydrazine catalyst, conditions and substrates, is discussed. Computational studies of the reaction mechanism are included. A stepwise process in which less strained olefins can undergo the reaction is also explored. Lastly, some initial explorations of transition metal complexes as catalysts for a carbonyl-olefin metathesis reaction are discussed, as well. In the second portion of this thesis, the use of cyclopropenimines as achiral organic superbases will be detailed. Previously, the Lambert group has developed this class of compounds as viable catalysts for asymmetric Michael and Mannich reactions. Cyclopropenimines are more basic than other commonly used organic bases, and therefore, can activate less acidic substrates. A simple, achiral cyclopropenimine was developed for use in base catalyzed or mediated processes. Several reactions have been explored as a comparison of cyclopropenimines to other commonly used bases.

Tobacco smoke particulate matter (PM) is a complex mixture of condensed organic compounds, with about 5 to 10% water. Its general properties are similar in some respects to that of atmospheric organic aerosol PM and thus provides a useful surrogate when studying atmospheric PM. Due to its ability to undergo acid-base chemistry, nicotine is of particular interest in the tobacco smoke system. The gas/particle partitioning of nicotine depends on the protonation state of nicotine in the particles, so the distribution of nicotine between these phases provides a means of understanding the acid-base balance in the tobacco smoke system. The goal of this work is to develop an acid-base balance for mainstream tobacco smoke that accounts for the extent of protonation of nicotine. Samples of extracted smoke particulate matter from seven brands of cigarettes were analyzed by ion chromatography (IC) and titration by both acid (HCl) and base (lithium phenoxide) for comparison with nicotine data collected by colleagues. IC analysis was used to quantify tracers of known acidic and basic species in tobacco smoke. Anion tracers for acids included: glycolate, acetate, formate, lactate, chloride, nitrite, sulfate, and nitrate. The cation tracers for base were ammonium, sodium, and potassium. The tobacco smoke extracts were also analyzed after acidification by the HCl titrant for changes in ammonia and organic acid concentrations to determine whether "bound" forms of these compounds were present in the PM. The titration data provided total concentrations of weak acid and bases in the samples. This titration data was compared with the concentrations of the tracers for weak acids and bases (along with the quantification of total nicotine by colleagues) to determine whether the IC analyses were accounting for all of the important species. The results of this comparison show that these analyses missed relevant species in the tobacco smoke system. As tobacco smoke PM is a complex organic mixture, the ability of acid species to protonate nicotine will be different than in aqueous media. The acidic species of interest were assumed to be either strong or weak, with the strong species assumed to be fully ionized after protonation of nicotine. Some portion of the weak acid species could then protonate any available nicotine. An electroneutrality equation (ENE) was developed for the tobacco smoke PM and populated using the IC data and the nicotine data obtained by colleagues. Using this ENE, the extent ionization of the weak acids species (α1A) and the net reaction constant for the protonation of nicotine by these weak acids (K*) was estimated. However, interpretation of the results were complicated by the underrepresentation of the pertinent weak acid species in our IC analyses. This study concluded that further work is needed to identify the missing weak acid and base species to obtain a better representation of the acid-base balance in tobacco smoke PM and to understand the ability of these weak acid species to protonate nicotine.