Reactions of O22+ with CO2, OCS and CS2

The reactivity of O-2(2+) 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 O-2(2+) OCS collision system we observe a channel forming a new chemical bond, generating SO2+ + 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 SO2++ O. Ab initio calculations support the presence of a collision complex in the pathway to SO+ +CO + O. The singleelectron transfer reactions are direct and the energy releases we extract for the subsequent dissociation of the primary products (e.g. O-2(+) + CO2+) show that the internal vibrational energy of the O-2(2+) reactant does not participate in the reaction. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.