Potential energy surface for carbon-dioxide activation by V+: A guided ion beam study

A guided ion beam tandem mass spectrometer is used to measure the kinetic energy dependence of the V+(5D) + CO2 reaction and a reverse pathway, VO+(3∑−) + CO. Two intermediates along these reaction pathways, V+(CO2) and OV+(CO), are examined by threshold collision-induced dissociation experiments with Xe. Thermochemical analyses of the cross sections obtained in these systems allow the measurement of D0(OV+–O) = 3.06±0.40 eV, D0(V+–CO2) = 0.75±0.04 eV, D0(OV+–CO) = 1.05±0.10 eV, and speculative characterization of electronic excitation energies for two states of VO+. Combined with literature information on the electronic states of V+ and VO+, these data enable the potential energy surfaces for this reaction system to be mapped out in some detail. We find that coupling between surfaces of different spin is observed, but that spin conservation plays an important role in both the forward and reverse reactions.