This research focuses on elucidating the chemistry of organic radical anions and cations that are considered to be key intermediates in a number of chemical and biochemical transformations. The rates of decay of these transient intermediates, generated chemically, electrochemically, or photochemically from selected precursors, will be measured as functions of precursor structure, solvent polarity and counter ion. Corresponding thermodynamic data, principally the free energy change associated with the ring opening of cyclic radical anions and cations, will be determined electrochemically by means of appropriate thermochemical cycles. Using selected precursors that have been or will be synthesized during the course of the experiments, and correlating the kinetic and thermodynamic data obtained for the corresponding radical anion or cation, structure-reactivity relationships of these short-lived intermediates will be developed. With this Award, the Organic and Macromolecular Chemistry Program supports the research and educational activities of Professor James Tanko of the Chemistry Department at Virginia Polytechnic University. Professor Tanko's research will focus on elucidating the structure-reactivity relationships that define the chemistry of reactive cationic and anionic radical intermediates. Although well known as intermediates in a number of organic transformations, these highly-reactive, short-lived intermediates are now thought to be intermediates in a number of pharmacological and enzymatic transformations. Professor Tanko's educational activities involve the education and training of postdoctoral, graduate and undergraduate students.
