Isotope and mass weighting effects in collinear triatomic reactive collisions

Abstract

A one-dimensional quantum mechanical reaction coordinate method has been developed by Rankin and Light [J. Chem. Phys. 51, 1701 (1969)] and Miller and Light [J. Chem. Phys. 54, 1635, 1643 (1971)] to study vibrational excitation of product molecules in reactive triatomic collinear collisions. In this paper the method is extended to study the isotopic reactions H+Cl2→HCl+Cl and D+Cl2→DCl+Cl. The observed results showed there is no change in the mean fraction of available energy entering product vibration. This is in agreement with previous experimental and classical trajectory study findings. The method is further used to study a reaction with a much different mass combination Cl+HI→HCl+I. We expect this reaction, from classical trajectory studies, to exhibit primarily ``mixed'' energy release. Also from classical studies, the different mass combinations for the reaction H+Cl2→HCl+Cl and the reaction Cl+HI→HCl+I are expected to lead to significantly different reaction dynamics. The one-dimensional quantum mechanical results are consistent with the classical results.