9307500 Butler The Experimental Physical Chemistry Program of the Chemistry Division is supporting Dr. Laurie Butler's work at the University of Chicago on chemical reactions in which failure of the adiabatic approximation is significant in determining the branching between chemical reaction channels. Experiments include photodissociation in Woodward-Hoffmann forbidden reactions, intermediate excitation of a parent molecule to alter its relative transition probabilities, and excitation to specific vibrational levels near the transition state. %%% Most of our understanding of the detailed mechanism of chemical reactions is based on the assumption that the motions of nuclei and electrons can be considered separately. This project deals with reactions in which that assumption is inadequate. The results will lead to a more general theory of reaction processes. ***