Collision complex model for spin forbidden reactions: Quenching of O(1D) by N2

A collision complex model based on the RRKM theory of unimolecular decomposition is developed to describe spin-forbidden molecular collision processes. The model is applied to the quenching of O(1D) atoms by molecular nitrogen. The calculated rate constant (300°K) is 7 × 10−11 cm3 mol−1 · sec−1, in excellent agreement with experiment. An average of roughly 30% of the 1.98 eV exothermicity of this process is predicted to go into product vibration. This suggests, in contrast to previous studies, that collision with O(1D) is a very efficient mechanism for vibrational excitation of N2.