Dynamic solvation effects on surface-impact dissociation of I₂^- (CO₂)_n

Surface-impact dissociation of I₂^- (CO₂)_n was studied by a molecular dynamics simulation in comparison with the experimental results. The branching fraction, f_dis, of the I₂^- dissociation was calculated as a function of the parent cluster size, n. This computational result reproduces the experimental one. We calculated a number of the I₂^- dissociation events starting from given initial orientations. The most favorable molecular orientation obtained supports the wedge effect in which a CO₂ molecule located at the waist position of the I₂^- core ion splits the I₂^- bond as if a piece of wood is split by a mechanical thrust against a wedge. The time profile of the wedge action calculated for the I₂^-(CO₂) impact shows that more than 20 % of the collision energy is converted to the vibrational energy of the I₂^-.