Regular Article

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

¹ School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
² Laboratoire Interdisciplinaire Carnot de Bourgogne (UMR CNRS 6303), Univ. Bourgogne Franche-Comté, 21078 Dijon Cedex, France
³ UFR ST, Université de Franche-Comté, 25030 Besançon Cedex, France

^b e-mail: susanta.mahapatra@uohyd.ac.in

Received: 20 August 2018
Received in final form: 7 November 2018
Published online: 21 December 2018

Abstract

State-to-state dynamics of the C(³P) + OH(X²Π, v = 0–2, j = 0) → CO (a³Π) + H (²S), reaction on the first (1²A^″) and second (1⁴A^″) 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 1²A^″ state and enhance the same on the 1⁴A^″ state. While the excess reagent vibrational energy releases mainly as product translation on the 1²A^″ state, the same releases as product vibration and rotation on the 1⁴A^″ state. The product rotational distribution is relatively cold on the 1⁴A^″ 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 1⁴A^″ 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.