Non-adiabatic effects in the reactions of strongly polar ions with molecules

Abstract

A theoretical study has been carried out on the effect of the inclusion of the C/r⁶ term, where C is a constant and r is the distance between the ion and the centre of mass of the molecule, into the interaction potential that describes the capture of an ion by a polar molecule. Recently, a rotationally adiabatic capture theory was used to show that the contribution from such terms alters the rate constants for the reactions of strongly polar ArH₃⁺ with H₂O and NH₃ by as much as ca. 20%. It is found in this work that non-adiabatic effects resulting from the coupling of the rotational motion of a dipole with the orbital motion of the system are also of importance. The magnitude of such effects depends on the molecular parameters of the system.