A theoretical study on the C plus OH reaction dynamics and product energy disposal with vibrationally excited reagent

摘要

State-to-state dynamics of the C(P-3) + OH(X-2, v = 0-2, j = 0) CO (a(3)) + H (S-2), reaction on the first (1(2)A) and second (1(4)A) excited states is studied by the real wave packet method of Gray and Balint-Kurti [S.K. Gray et al., J. Chem. Phys. 108, 950 (1998)]. Product state-resolved (both vibrational and rotational) and total reaction probabilities are calculated for the total angular momentum, J = 0. Product vibrational and rotational distributions are also examined at five different collision energies to elucidate the reaction mechanism. Reagent vibrational excitation is found to decrease the reactivity on the 1(2)A state and enhance the same on the 1(4)A state. While the excess reagent vibrational energy releases mainly as product translation on the 1(2)A state, the same releases as product vibration and rotation on the 1(4)A state. The product rotational distribution is relatively cold on the 1(4)A state. Despite same mass combination and same exoergicity, the drastic differences of the dynamics of the reaction on the two excited states are related to the microscopic topology of the underlying reaction path. The late barrier present on the 1(4)A state plays crucial role on the reaction dynamics at the state-to-state level. The results of the present study are compared with the available literature data.