Size-specific reactivities of vanadium oxide cluster cations

This article is intended to summarize recent studies on the reactivity and dynamics of gas-phase vanadium oxide cluster cations in terms of their depe ndence on the size and stoichiometry of the selected clusters. In addition, the effects of coordination, oxidation states of the vanadium atoms, influ ence of charge, and ionization potentials on the reactivity of these cluste rs are presented. Reactions of the clusters V3O7+ and V5O12+ with 1-butene, 1,3-butadiene, and difluoromethane differ significantly from those of simi lar clusters such as V3O6+ and V5O11+. While oxygen transfer and carbon-car bon cracking reactions are observed for the former clusters, the latter pri marily associate the neutral reactant species. These differences are largel y related to the oxidation states of the vanadium atoms within the cluster, but also display a dependence on the size of the cluster, with the smaller clusters being more reactive than the larger ones. Reactions with carbon t etrachloride display a dependence on the coordination of the clusters, but also display a distinct change in reaction channels from the chloride trans fer reaction for the smaller clusters to the oxidative chloride transfer an d formation of neutral phosgene for cluster with more than three vanadium a toms. In contrast, the dehydrohalogenation reactions of CH3 CF3 display lit tle dependence on the size of the clusters.