The kinetics and dynamics of the multichannel multiwell reaction of CO(1Σ+) with OH(2Π): theoretical investigation

Abstract

The kinetics and mechanism of the gas-phase reaction between carbon monoxide and hydroxyl radical have been theoretically investigated on the lowest potential energy surface. The dynamics of the reaction of CO(1Σ+) with OH(2Π) is studied by stochastic one-dimensional chemical master equation (CEM) simulation method. The role of the energized intermediates on the kinetics of the reaction was investigated by determination the fraction of different intermediates and products at the early stages of the reaction. The temperature dependence of the rate constants of the each individual channels of the reaction over a wide range of temperature (200–2000 K) was studied. The calculated rate constants from the CEM simulation were compared with those obtained from the RRKM–SSA [Rice–Ramsperger–Kassel–Marcus (RRKM) theory and Steady State Approximation (SSA)] method based on strong collision assumption. At lower temperatures, the calculated RRKM–SSA rate constant was found to be twice of the calculated by CEM, although the results are in good agreement with experimental values.