The intermolecular potential in NO-N2 and (NO-N2)+ systems:: implications for the neutralization of ionic molecular aggregates

The characterization of the non covalent interaction potential, responsible for the intermolecular bond in NO-N-2 and (NO-N-2)(+) molecular aggregates, has been achieved by coupling the predictions of a semiempirical method with the results of a scattering experiment and ab initio calculations. The potential wells for the most stable configurations of the neutral and ionic state, having approximatively a T shape in both cases, fall in the same intermolecular distance range. In addition, in the ionic state, the charge is completely localized on the NO partner. Important implications on the dynamics of the neutralization process, occurring as a vertical transition from ionic to neutral state, are obtained by exploiting the analytical formulation of the interaction and calculating energy spacings and relevant Franck-Condon factors for both intramolecular and intermolecular vibration modes.