State-to-state quantum dynamics of the H(2S) + O2(ã1Δg) → O(3P)+OH(2Π) reaction on the first excited state of HO2(Ã2A′)

Abstract

State-to-state differential and integral cross sections for the title reaction were calculated using an exact wave packet method on a recently developed ab initio potential energy surface of the first excited state HO₂(òA′). The calculation results indicate that the reaction is dominated by highly rotationally excited OH products scattered in both the forward and backward directions, consistent with the formation of a long-lived HO₂ reaction intermediate. However, a statistical model was found to overestimate the integral cross sections, due apparently to dynamical bottlenecks. In addition, a unique feature in the OH + O exit channel potential promotes rotational excitation of the departing OH product by exerting a torque force. The role of the title reaction in high temperature combustion is also discussed.