NONADIABATIC EFFECTS IN THE REACTIONS OF STRONGLY POLAR IONS WITH MOLECULES

A theoretical study has been carried out on the effect of the inclusio n of the C/r(6) term, where C is a constant and r is the distance betw een the ion and the centre of mass of the molecule, into the interacti on potential that describes the capture of an ion by a polar molecule. Recently, a rotationally adiabatic capture theory was used to show th at 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. 2 0%. It is found in this work that non-adiabatic effects resulting from the coupling of the rotational motion of a dipole with the orbital mo tion of the system are also of-importance. The magnitude of such effec ts depends on the molecular parameters of the system