Dinitrogen Splitting without Barrier or Visible Light-Driven: Reactions of Vanadium Trimers and Dimers with Dinitrogen.

The reaction of V atoms and small clusters with dinitrogen has been investigated by matrix isolation in solid Ne and by complementary quantum chemical calculations. The experiments disclose striking differences between the reactivity of V atoms, dimers, and trimers toward dinitrogen. Whereas V atoms react only by formation of complexes, both V and V react by cleavage of the N triple bond to form nitride clusters. Whereas V reacts immediately at the conditions of matrix deposition, the reaction of V requires activation by irradiation with visible light. There is evidence for two isomers of VN, a planar one with a A electronic term and a long V─V distance, and a folded one with a A term and a short V─V distance. Furthermore, there are also complexes of V and V with N that contain activated N units.