This grant in the Organic Dynamics Program provides support for the continuing research of Dr. William Dolbier of the University of Florida. The thrust of the research is the study of the unique kinetic and thermodynamic effects of fluorine substituents on the mechanisms of thermal homolytic and pericyclic reactions. Experiments have been designed which will provide a fundamental understanding of the origin of the previously observed dramatic substituent effects. Included are experiments designed to test the influence of substituent mass upon the rotational component imparted during carbon-carbon bond cleavage and a test of the feasibility of tuning the thermodynamics of electrocyclic equilibria. Innovative mechanistic probes such as high pressure techniques, kinetic isotope effects, stereochemical probes, solvent effect studies and correlation of theory with experiment will be employed to study the mechanisms of electrocyclic reactions, (2+2), (2+4) and 1,3-dipolar cycloadditions and a number of reactions involving homolytic formation of diradicals.
