Towards State-to-State Photodissociation Dynamics of Polyatomic Free Radicals: Probing Nonadiabatic Processes and Competitive Pathways

University Of California-Riverside, Riverside CA

Investigators

Abstract

In this project funded by the Chemical Structure, Dynamics and Mechanisms program of the Chemistry Division, Professor Jingsong Zhang of the University of California at Riverside investigates the photodissociation dynamics of polyatomic free radicals. Free radicals are important reactive intermediates in many reactive chemical environments. The fundamental knowledge (spectroscopy, energetics, reaction mechanisms, etc.) from this work is valuable to the combustion, atmospheric chemistry, and organic chemistry communities, as well as the theoretical chemistry and physics communities. The broader impacts of this work also include advancing education and training of graduate students, promoting undergraduate research experience of women and underrepresented minority at the University of California at Riverside. The project also includes outreach to a diversified student population of the Riverside and San Bernardino community colleges. The goal of this research is to provide quantitative understanding of the photo-chemical reactivity of prototypical polyatomic radicals and their nonadiabatic dynamics and competitive pathways at quantum accuracy. The project focuses on several benchmark systems, such as the methyl, ethynyl, and HCO radicals. The H-atom photoproducts of these systems are characterized using the high-resolution, high-sensitivity high-n Rydberg atom time-of-flight (HRTOF) technique as the main experimental tool. This technique provides state-resolved or even state-to-state product energy and angular distributions. These experiments aim to render high-quality data and benchmarks to test high-level quantum mechanical theories of the excited open-shell species.