Date of Award:

5-2012

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Chemistry and Biochemistry

Committee Chair(s)

Vernon D. Parker

Committee

Vernon D. Parker

Committee

Lance C. Seefeldt

Committee

Alvan C. Hengge

Committee

Roger A. Coulombe

Committee

Cheng-Wei Tom Chang

Abstract

In chemistry, kinetics is the study of the rates of chemical reactions. A reaction mechanism describes in detail exactly what takes place at each stage of an overall chemical reaction from reactants to products. The work outlined in this dissertation was carried out in order to find out the true mechanisms of some fundamental organic reactions of nitro compounds by means of a series of novel kinetic techniques and analysis methods.

The target reactions include (1) the proton transfer reactions of nitroalkanes and (2) the aromatic nucleophilic reactions of trinitroarenes, both of which are undeniably among the most elementary and significant processes in organic chemistry and biochemistry.

Rigorous kinetic investigations have found that both reactions actually take place by multi-step mechanisms involving kinetically significant intermediates. This result challenges the long-held assumption that the reactions follow a simple one-step mechanism. Although the assumption of the one-step mechanism can be applied to evaluate the magnitude of the rate of the overall reaction, it fails to provide a detailed description of chemical reactions, especially those behaving abnormally. This is obvious in the conundrum found in the description of the proton transfer reactions of nitroalkanes which is commonly known as the nitroalkane anomaly. However, adopting the multi-step mechanisms proposed in this dissertation should end this chapter of organic chemistry.

Reaction mechanism is a primary topic for organic chemical studies that provides a framework for appropriate application in the chemical and pharmaceutical industry, and in agricultural applications. An essential objective of this work is to point out that more attention should be paid to the importance of reaction mechanism in the field of organic chemistry. A broad impact of this work on academic studies may be achieved via promoting a revision of the mechanisms believed to be established over the past seventy years. It will have a broad effect in other branches of chemistry as well as in biochemistry.

This work is a sub-project of the three-year $665,000 international cooperative project of “Is the single transition state model appropriate for the fundamental reactions of organic chemistry?” initiated by Professor Vernon D. Parker at USU, collaborating with Professors Jin-Pei Cheng and Xiao-Qing Zhu in China’s Nankai University. This international project, supported by both NSF (National Science Foundation) and NSFC (National Natural Science Foundation of China), has been fostering cooperation and good will between the scientific communities of the United States and China.

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Comments

This work made publicly available electronically on December 21, 2012.

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