An investigation of the competition between energy randomization and chemical reactivity in a series of carefully chosen reactions will be conducted with the goal of testing the RRKM theory of kinetic reactivity. The addition of carbon labelled singlet methylene to selected dienes and a fluorinated aryl vinyl system will be evaluated. Perturbation of the Cope rearrangement by phenyl groups will also be investigated. In addition, the concept of solvent friction and the resultant effect on chemical reactivity of steroidal heptaenes will be investigated under a variety of conditions. Finally, the effect of configuration and substitution on the stability of pentadienyl radicals will be determined, and the two-step dimerization of polyenes will be explored. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor W. Doering at Harvard University. The studies are designed to provide critical information for a number of reactions which proceed upon exposure to heat. The objective of the investigation will be to determine how molecules decide to direct the energy they absorb: do they distribute the energy evenly throughout the molecule or do they direct the energy to weak parts of the molecule which subsequently undergo specific chemical reactions? Another aspect of the investigation will be to determine the critical effect that solvent viscosity has on the reactions of chemical species that are comprised of a series of doubly bonded carbon atoms.
