Adsorption And Activation Of Nitrogen Molecules By A Polynuclear Vauadium Nitrogen Anion Cluster

Nitrogen is colorless,odorless and one of the most abundant gases in the atmosphere.It is of great significance for the living of human to convert nitrogen,which is rich in resources and cheap in cost,into available nitrogen-containing compounds by activation.However,nitrogen has extremely stable chemical properties and it is very difficult to react with other substances,so nitrogen fixation is the primary step in the whole process of nitrogen activation and transformation.The side-on-end-on coordination of N2 can be very important to activate and functionalize this very stable molecule while such coordination has been rarely reported.This study reports the gas phase reaction of a polynuclear vanadium nitride cluster anion V5N5-with N2 by the reflectron time-of-flight mass spectrometer,photoelectron imaging spectroscopy and density functional theory calculations.The quantum chemistry modelling suggests an unusual side-on-end-on coordination in the major species of adsorption product V5N7-,the binding efficiency of N2 is 12%.In order to explore the bonding mechanism of N2 bound to V5N5-cluster by side-on-end-on,this paper further carried out the natural charge analysis and orbital analysis of identified side-on-end-on structures.The analysis shows that the back-donation interaction between the localized d-d bonding orbital on low coordinated dual metal(V)sites and the antibonding ?*orbitals of N2 are the driving forces to adsorb N2 with a high binding energy(about 2.0 eV).