The structure, chemical properties, photoreactivity, and new routes for the generation of anions, stable radicals, and radical ions will be investigated in this project. Structure will be determined for these intermediates by a comparison of solution phase and solid state nmr spectroscopy, by electrochemical techniques, and by employing transient and steady state illumination as probes for excited state reactivity. Of particular interest will be the determination of how structure influences the acidities and oxidation potentials of several families of dianions, radical ions, and stable radicals. Fundamental thermochemical information will be attained by correlating rates of photochemical and thermal electron transfer with redox potentials derived by high speed cyclic voltammetry or photomodulation voltammetry. A new thrust exploring photochemistry in supercritical fluids will seek to probe solvation effects under carefully controlled conditions. In these studies, scientifically important questions will be probed of how aggregation, environment, and solvation affect chemical reactivity, particularly electron transfer reactions. This grant from the Organic Dynamics Program supports the continuing work of Professor Marye Anne Fox at the University of Texas, Austin Campus. This research will generate results of a fundamental nature about reactive intermediates in chemical reactions. The mechanistic basis of organic chemistry rests on an understanding of the properties of reactive intermediates and their involvement in chemical transformations. Knowledge of these intermediates will provide chemists with a better ability to predict the course of chemical reactions.
