Theoretical study of the reaction of Ti+ with SCO in gas phase

The quartet and doublet potential energy surfaces for the reaction of Ti+ + SCO have been calculated at the UQCISD(T)/6-311+G*// UB3LYP/6-311+G* level of theory. The present results show that the reaction mechanism is insertion-elimination mechanism both along the C-S and C-O bond activation branches, but the C-S bond activation is much more favorable than the C-O bond activation in energy. The minimum energy reaction path is found to involve the spin inversion in the reaction steps. Specifically, the reaction is most likely to proceed through the following steps: Ti-4(+) + SCO -> (4)IM1 -> CP1 -> (2)IM2 -> (TiS+)-Ti-2 + CO. The overall reaction is calculated to be exothermic by 98.2 kJ/mol, which is in good agreement with the available experimental results. (c) 2006 Elsevier B.V. All rights reserved.