Effect of reagent rotation on the dynamics of the O + + H 2 ion—molecule reaction and isotopic variants

Abstract

The moderately exothermic ion—molecule reaction O + + H 2 and its isotopic variants have been the subject of several dynamical studies in our group. In this work we report an extensive quasiclassical trajectory study on the dynamics of this system at different initial relative energies considering a wide range of initial J quantum rotational numbers of the H 2, D 2 or HD reactant molecules. The observed cross section S r versus J curves can be well rationalized in terms of competing orientational and energy effects, but the behaviour of the fraction of OH + molecules produced in the O + + HD reaction with J admits no simple explanation. The observed trends tend to smooth out at higher energies, in accordance with theoretical expectations.