Side-on-End-on Coordination of Dinitrogen on a Poly-Nuclear Vanadium Nitride Cluster Anion V5N5.

The side-on-end-on coordination of N-2 can be very important to activate and functionalize this very stable molecule. However, such coordination has rarely been reported. This study reports a gas-phase species (a polynuclear vanadium nitride cluster anion [V5N5](-)) that can capture N-2 efficiently (12 %), and the quantum chemistry modelling suggests an unusual side-on-end-on coordination. The cluster anions were generated by laser ablation and the reaction with N-2 has been characterized by mass spectrometry, photoelectron imaging spectroscopy, and density functional theory calculations. The back-donation interactions between the localized d-d bonding orbitals on the low-coordinated dual metal (V) sites and the antibonding pi* orbitals of N-2 are the driving forces to adsorb N-2 with a high binding energy (about 2.0 eV).