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

Abstract 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 2 and V 3 react by cleavage of the N 2 triple bond to form nitride clusters. Whereas V 3 reacts immediately at the conditions of matrix deposition, the reaction of V 2 requires activation by irradiation with visible light. There is evidence for two isomers of V 2 N 2 , a planar one with a 5 A u electronic term and a long V─V distance, and a folded one with a 1 A 1 term and a short V─V distance. Furthermore, there are also complexes of V 2 and V 3 with N 2 that contain activated N 2 units.