Exploring Mode Selective Behavior in State-Resolved Unimolecular Reactions

University Of California-San Diego, La Jolla CA

Investigators

Abstract

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Sinha will conduct research on unimolecular reactions that deviate from the traditional description by the RRKM statistical theory. Gas phase molecules are prepared in selected ro-vibrational states above the dissociation limit of the ground electronic state by double resonance excitation. These excited molecules revert to lower energies, dissociate at a given rate, and present a final product state distribution. The resonance energy and the line widths provide information about the potential energy surface, whereas the final product state distribution reflects the dynamics of the system as it evolves from the transition state to the products. Systems to be investigated include hypochlorous acid, pernitric acid, and methyliodide, as these are believed to exhibit non-statistical reaction dynamics. This research deals with fundamental aspects of chemical reactions in the gas phase. Whereas many reactions can be described by a statistical theory, there are some for which a statistical theory of reactions does not apply. This research is focused on the reaction dynamics of several molecular species for which non-statistical behavior is suspected. The results of this work will add to the fundamental understanding of reaction chemistry, and may be applicable to problems of atmospheric and combustion chemistry. Students will participate in this research and thereby acquire knowledge and skills in preparation for entry into the scientific/technical workforce.