An atom-in-molecules and electron-localization-function study of the interaction between O2 and VxOy+/VxOy (x=1, 2, y=1-5) clusters

The most stable structures of VxOy+/VxOy (x = 1, 2, y = 1-5) clusters and their interaction with O-2 are determined by density functional calculations. the B3LYP functional with the 6-31G* basis set. The nature of the bonding of these clusters and the interaction with O-2 have been studied by topological analysis in the framework of both the atoms-in-molecules theory of Bader and the Becke-Edgecombe electron localization function. Bond critical points are localized by means of the analysis of the electron density gradient field. delrho(r), and the electron localization function gradient field. deleta(r). The values of the electron density properties, i.e.. electron density, rho(r). Laplacian of the electron density. del(2) rho(r). and electron localization function, eta(r), allow the nature of the bonds to be characterized. arid linear correlation is found for the results obtained in both gradient fields. Vanadium-oxygen interactions are characterized as unshared-electron interactions. and linear correlation is observed between the electron density properties and the V-O bond length. In contrast. O-2 units involve typical shared-electron interactions, as for the dioxygen molecule. Four different vanadium-oxygen interactions are found and characterized: a molecular O-2 interaction, a peroxo O-2(2-) interaction, a superoxo O-2(-) interaction and a side-on O-2(-) interaction.