Collision-induced dissociation of CO₂⁺ ions

Abstract

Collision-induced dissociation experiments have been conducted on CO₂⁺ ions using three types of ion sources, different collision energies, light and heavy targets, and three different apparatuses possessing different values of energy and angular resolution. Results of all these collision experiments establish that collision-induced dissociation dynamics is remarkably different from that obtained in photoionization experiments. Although the O⁺ + CO channel is the energetically lowest dissociation pathway, dissociation into CO⁺+O is found to be the preferred channel. Our measurements of the ratio CO⁺ to O⁺ are substantially higher than that obtained in photoionization experiments. Determinations of kinetic energies released upon dissociation of CO₂⁺ are also made. Rationalization of our results is attempted in terms of curve crossings of low-lying excited states of CO₂⁺ ions.