Nitrogen Activation and Transformation on Monometallic Niobium Boron Oxide Cluster Anions at Room Temperature: A Dual-Site Mechanism

Dinitrogen activation and transformation at room temperature is a goal that has been long sought after. Despite that, it remains underdeveloped due to being a challenging research area and the need for a better mechanistic understanding. Herein, we report that well-defined NbB3O2- gas-phase clusters can activate one N2 molecule and generate the products B3N2O- and B3N2O2-, as applying mass spectrometry and theoretical calculations. This unusual N2 activation reaction results from the different functions of the Nb and B3O2 moieties in NbB3O2-. Theoretical calculations suggest that a catalytic cycle can be completed by the recovery of NbB3O2-, which is achieved through the reactions of Nb and NbO with B3O2- and B3O-, respectively. This is the first example of N2 efficient transformation at a monometallic cluster, and this method for generating dual active sites by designing proper ligands may open the way toward the development of more effective N2 fixation and functionalization methodologies.