Type of Document	Dissertation
Author	Phillips, Janice Paige
URN	etd-102498-111245
Title	Rearrangements of Radical Anions Generated from Cyclopropyl Ketones
Degree	PhD
Department	Chemistry
Advisory Committee	Advisor Name Title Tanko, James M. Committee Chair Anderson, Mark R. Committee Member Brewer, Karen J. Committee Member Castagnoli, Neal Jr. Committee Member Gibson, Harry W. Committee Member Wolfe, James F. Committee Member
Keywords	Marcus theory Homogeneous catalysis Reaction mechanism and kinetics Cyclopropyl ketones Voltammetry Cathodic reduction Ring opening Radical anion
Date of Defense	1998-05-04
Availability	restricted
Abstract Cyclopropyl-containing substrates have been frequently utilized as "probes" for the detection of SET pathways in organic and biorganic systems. These reactions are based on the cyclorpropylcarbinyl - homoallyl rearrangement, which is fast and essentially irreversible. The implicit assumption in such studies is that if a "radical" species is produced, it will undergo ring opening. We have found that there are two important factors to consider in the design of SET probes: 1) ring strain, the thermodynamic driving force for the rearrangement, and 2) resonance energy, which may help or hinder rearrangement, depending on the specific system. Delocalization of spin and charge were found to be important factors pertaining to substituent effects on the rates of radical anion rearrangements. Previous studies from our lab have centered on highly conjugated phenyl cyclopropyl ketones. This work considers a series of compounds varying in their conjugative components from a highly conjugated spiro[2.5]octa-4,7-dien-6-one and derivatives to simple aliphatic ketones. Utilizing cyclic, linear sweep voltammetry, and preparative electrolysis techniques, it was discovered that all substrates yielded ring opened products with rates and selectivities that will prove useful and informative in the design of mechanistic probes based on the cyclorpropylcarbinyl - homoallyl rearrangement. Rates of homogeneous electron transfer from a series of hydrocarbon mediators to substrates were measured using homogeneous catalysis techniques. Standard reduction potentials and reorganization energies of substrates were derived using Marcus theory. Conjugative interactions with the cyclopropyl group are discussed.
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