Dinitrogen Activation by a Heterometallic VFe Complex Derived from 1,1'‐Bis(arylamido)vanadocene

For dinitrogen activation mediated by a heterobimetallic VFe complex, synthesis and reduction of a novel iron complex having 1,1'‐bis(mesitylamido)vanadocene were performed. Reaction of the vanadocene ligand 2 with iron dichloride afforded a heterobimetallic VFe complex 3, characterized by X‐ray crystallographic study. The molecular structure of the complex 3 showed the short V–Fe distance of 2.6373(3) Å, indicative of the bonding interaction between two metals. Reduction of the complex 3 with KC8 under a nitrogen atmosphere was found to result in the formation of a three‐coordinate iron dinitrogen complex 4, in which the dinitrogen moiety shows one of the longest N–N bond lengths for iron dinitrogen complexes. Reduction of the complex 3 under an argon atmosphere was performed to isolate a reduced species [K(thf)5][3] as a reactive intermediate, whose structure was also determined by X‐ray crystallography. Reduction of a novel heterobimetallic VFe complex derived from 1,1'‐bis(arylamido)vanadocene was found to result in the formation of a three‐coordinate iron dinitrogen complex. In X‐ray crystallographic study of this complex, the dinitrogen moiety shows one of the longest N–N bond lengths for reported iron dinitrogen complexes.