With this renewal award, the Organic and Macromolecular Chemistry Program continues its support of the work of Professor Barry Carpenter of the Department of Chemistry at Cornell University. The research will extend the PI's studies of nonstatistical dynamics in organic reactions. Largely as a result of Professor Carpenter's work it has recently been recognized that many reactive intermediates in organic chemistry are formed with selective excitation of their available vibrational modes. If these intermediates go on to products faster than they undergo vibrational energy redistribution, the reaction does not always follow the lowest energy path and leads to unexpected products. In this proposal, experiments designed to synthesize and investigate molecules that may lead to additional reactive intermediates in which the energy is distributed in a nonstatistical manner will be carried out. One principal focus of the work, which combines modern computational chemistry with sophisticated experiments, will be on those intermediates lying in deep energy minima and the role of nonstatistical dynamics on their reactivity. A second theme of the project is to broaden the range of reactions in which issues of nonstatistical dynamics can be explored. Primarily, these effects have been proposed for thermally generated singlet biradicals. In the new work, the ideas will be extended to photochemistry, to carbene chemistry, and to the chemistry of chemically activated stable molecules.
A general goal of the project is to update models of chemical kinetics to take account of dynamic effects. Since chemical kinetics plays vital roles in biology, atmospheric and environmental chemistry, combustion, and in a variety of other domains, improving the accuracy of kinetic models is expected to have wide-ranging impact. In addition, the highly interdisciplinary training that students will receive as participants in this research will help provide the expertise that modern scientific research now demands.
