Effect of pendular orientation on the reactivity of H + DCl: a quasiclassical trajectory study

The stereodynamics of the reaction of H + DCl yielding an exchange (D + HCl) and an abstraction (HD + Cl) channel has been investigated by the quasiclassical trajectory method using the most accurate potential energy surface available. The calculations were carried out for conditions that appear experimentally feasible; the corresponding calculated integral and differential cross sections differ significantly for different orientations of the external electric field with respect to the collision velocity vector. The results reveal that the exchange channel is brought about by two collisional mechanisms, distinguished by the direction along which the H atom approaches the DCl molecule. Such insight can only be gained from the study of collisions of oriented reactant molecules.