Cycling between Molybdenum‐Dinitrogen and ‐Nitride Complexes to Support the Reaction Pathway for Catalytic Formation of Ammonia from Dinitrogen.

Cycling between molybdenum(I)‐dinitrogen and molybdenum(IV)‐nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second‐order reaction rate for the conversion of the molybdenum‐dinitrogen complex into the molybdenum‐nitride complex indicates that the formation of the dinitrogen‐bridged dimolybdenum complex is involved in the rate‐determining step. DFT calculations indicate that the molybdenum‐dinitrogen complex transforms into the molybdenum‐nitride complex via direct cleavage of the nitrogen‐nitrogen triple bond of the bridging dinitrogen ligand of the dinitrogen‐bridged dimolybdenum complex. The corresponding reaction of the molybdenum‐nitride complex transforming into the molybdenum‐dinitrogen complex proceeds via the ligand exchange of ammonia for dinitrogen at the dinitrogen‐bridged dimolybdenum complexes. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results. [ABSTRACT FROM AUTHOR]