Electronic Properties and Chemical Bonding of O-Rich Clusters MM′O7 − (M, M′ = V, Nb, Ta)

Abstract

Density functional theory (DFT) calculations are carried out to investigate the electronic and structural properties of a series of bimetallic oxygen-rich clusters, MM′O7 − (M, M′ = V, Nb, Ta). Generalized Koopmans’ theorem is applied to predict the vertical detachment energies (VDEs) and simulate the photoelectron spectra (PES). Theoretical calculations at the B3LYP level yield dibridged structures with doublet state (C s, 2A′′) as ground states for the anionic clusters. Intriguingly, an O2 unit is found to be bonded to the metal atom which is inclined to donate electrons in the MM′O7 − (M, M′ = V, Nb, Ta) species. The extremely high binding energies, above 5.50 eV, are due to oxygen 2p-based orbitals and suggest that these clusters are strong oxidizers. Chemical bonding analyses reveal superoxide in the oxygen-rich clusters, in excellent consistence with their structural characteristics.