Vibrationally and Rotationally State-Resolved Differential Cross Sections for Reactive Scattering

Mark Keil and Gregory A. Parker of the University of Oklahoma are supported by the Experimental Physical Chemistry Program to continue their investigations on state-to-state reaction dynamics for various simple reactions: (i) fluorine atoms plus hydrogen dimer to form hydrogen fluoride; (ii) fluorine atoms and hydrogen chloride to form hydrogen fluoride and chlorine atoms; (iii) chlorine atoms and hydrogen bromide to form hydrogen chloride and bromine atoms. The reaction of interest takes place at the intersection of two crossed molecular beams. A high-resolution chemical laser in conjunction with a bolometer detector is then used to resolve the scattered product vib-rotational state and angular distribution. The PIs will explore the effects of varying initial rotational and kinetic energies, and isotopic substitutions, upon the vibrationally and rotationally state-resolved differential cross sections. Direct comparisons will be made with ab initio theoretical dynamical calculations using quantum scattering codes developed by the co-PI. The principal goal of these studies is to deepen our understanding of chemical reaction dynamics at the detailed state-to-state level. Tremendous theoretical progress is currently being made using approximation techniques for simplifying increasingly complex chemical reactivity problems. The validity of approximations used in such quantum calculations is often based upon experience with tri-atomic A+BC systems of the sort studied here: detailed investigations of A+BC systems have provided the foundation upon which larger systems can be understood. The field of detailed chemical reaction dynamics is helping elucidate chemical reactivity very broadly, with obvious relevance to all branches of chemistry.