In this project funded through the Faculty Early Career Development (CAREER) Program of the Chemistry Division, Professor Susan Graul of the Department of Chemistry of the Carnegie- Mellon University will study the thermochemistry, kinetics, and dynamics of gas-phase ion-molecule reactions. Reaction cross sections and product angular and energy distributions will be determined using mass-analyzed ion kinetic energy spectrometry and guided ion-beam techniques. Initial studies will focus on the exothermic bimolecular nucleophilic substitution (SN2) reactions of methyl halides CH3X (X=Cl,Br,I) with F- and Cl- ions. These studies will be extended to other systems such as the reactions of F- and Cl- ions with chloroacetonitrile and bromoacetonitrile, and others. Furthermore, bimolecular elimination reactions will also be investigated. These experimental studies will be complemented by electronic structure calculations for relevant reaction intermediates and transition states, and statistical theoretical modeling of the reactions studied for comparison with experimental results. Accompanying the research activity is a specified education effort appropriate to the development of a full, balanced, academic career. The chemistry of ion-molecule reactions is at the forefront of gas phase reaction chemistry. As such it plays an important role in the chemistry of combustion processes, the chemistry of the upper atmosphere, and other areas. This research will contribute to our understanding of these processes by providing data suitable for the development of advanced theoretical, molecular based models of chemical reactions.
