Reactions of O22+ with CO2, OCS and CS2

The reactivity of O22+ with CO2, OCS and CS2 has been investigated for the first time, at centre-of-mass collision energies of 7.0, 7.9 and 8.5 eV, respectively. The position-sensitive coincidence technique we employ shows the reactivity in the three collision systems is dominated by double- and single-electron transfer. Analysis of the observed electron transfer reactivity indicates that the two-electron transfer is concerted and the translational energy does not couple efficiently to the electronic co-ordinates. In the O22+ + OCS collision system we observe a channel forming a new chemical bond, generating SO+ + CO+ + O. The angular scattering in this channel indicates that this reaction proceeds via complexation, then fragmentation of the complex to form SO2+ + CO+. The primary SO2+ product then dissociates to SO+ + O. Ab initio calculations support the presence of a collision complex in the pathway to SO+ + CO+ + O. The single-electron transfer reactions are direct and the energy releases we extract for the subsequent dissociation of the primary products (e.g. O2+ + CO2+) show that the internal vibrational energy of the O22+ reactant does not participate in the reaction.