Effect of internal excitations of reagent diatom on initial state-selected dynamics of C + OH reaction on its second excited (1⁴A″) electronic state^*

Abstract

Initial state-selected total reaction probabilities and integral reaction cross sections (ICSs) of, C(3P) + OH (X2Π) → CO(a3Π) + H (2S), reaction on its second excited electronic state (14A″) are calculated with the aid of a time-dependent wave packet propagation method within the coupled states approximation. Partial wave contributions for the total angular momentum quantum number, J=0–48, were necessary to obtain converged ICSs for OH (v=0, j=0) upto a collision energy of ∼0.25 eV. In case of rotationally and vibrationally excited OH, many more partial wave contributions had to be included. Dense oscillatory structures are found in total reaction probabilities due to the formation of quasibound collision complexes inside the wells (of depth ∼2.25 eV and ∼1.85 eV) present on the potential energy surface. While reagent vibrational excitation promotes the reaction, no such general trend is found with rotational excitation. The results of the present study are compared with the literature data. Mechanistic details of the C + OH reaction occurring on its ground, first and second excited electronic states are compared and discussed.