Product vibrational distributions in CH 3Br photodissociation

Abstract

We performed a theoretical study of the photodissociation dynamics of CH 3Br in the A ∼ band using a wavepacket propagation technique on coupled ab initio potential energy surfaces corresponding to the 3Q 1 and 1Q 1 states correlated at large distance with the Br ground spin–orbit state, as well as the 3Q 0 and 4E states correlated to the excited one. The methyl umbrella vibrational product state distributions are found in very good agreement with experimental results. They are hotter for Br than for Br ∗, and this is related to the shapes of the 3Q 0 and 1Q 1 potentials.