With this award, the Organic and Macromolecular Chemistry Program supports the work of Professor Olaf G. Wiest of the Department of Chemistry and Biochemistry at the University of Notre Dame, Notre Dame, IN. The research will continue the PI's experimental and computational investigations of the chemistry of hydrocarbon radical cations, a class of reactive intermediates that have significant potential for new scientific insights and applications. Radical cations, which are formed through electron transfer, typically react many orders of magnitude faster than their neutral counterparts. After back electron transfer, this results in a very effective method for the acceleration of reactions through electron transfer catalysis. Stereochemical and isotope effect studies will be used to elucidate the mechanistic details of these reactions that are often controlled by factors absent or less important in their neutral counterparts. The reactivity and selectivity of electron transfer reactions in ionic liquids, in which polarity facilitates radical cation formation, will be investigated. These experimental studies will be complemented by high-level quantum mechanical calculations of reaction dynamics. These investigations will yield basic information that will provide the means to control electron transfer catalysis and facilitate its application in modern synthetic organic chemistry. Such fundamental knowledge is essential for the application of this technique to other areas of chemical, biological and material science.