CAREER: Femtosecond Time Resolution in Electron Collision Initiated Reactions

Washington University, Saint Louis MO

Investigators

Abstract

This award, funded by the Experimental Physical Chemistry Program of the Division of Chemistry will support Professor Richard Mabbs of Washington University and his graduate and undergraduate students in their studies of the molecular dynamics of dissociative electron attachment (DEA). The proposed work will extend current molecular level, ultra-fast time-resolved experimental capability to electron collision induced reactions. Techniques based on a novel combination of cluster anion production and ultra-fast laser interrogation will be developed to follow the atomic motions at the instant of the photo-induced electron attachment. Time-resolved photoelectron imaging spectroscopy will follow the evolution of the produced transient anionic species into stable product anions, directly probing the potential energy surface along the reaction coordinate. The initial experimental focus will be on simple methyl halide systems, but later work will extend to larger molecules. The interpretation of experimental results will be supported by ab initio electronic structure calculations and qualitative/semi-quantitative models. The educational component of this CAREER award will incorporate highly visual photoelectron imaging results into the curriculum. The images are intuitively explained using qualitative models, thus providing concrete illustrations of quantum concepts. DEA is a widespread phenomenon important in such diverse areas as the mechanism of ionizing radiation damage of DNA, plasma remediation of pollutants from air streams, interstellar chemistry and the chemistry of the earth?s ionosphere. Direct study of the fundamental details of DEA will allow testing and refinement of current theoretical treatments and lead to more accurate predictive/interpretive models of mechanisms involving these processes. The active involvement of undergraduate students at all levels is strongly encouraged in this research program. Undergraduates involved in these activities will develop problem solving abilities, analytical skills, critical thinking skills and will develop a long term interest in the physical sciences.