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

Abstract

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.

Two-Coordinate Iron(I) Complexes on the Edge of Stability: Influence of Dispersion and Steric Effects

“…The LFeNNFeL complex was doubly reduced to the Fe 0 –N 2 complex, which further lengthens the N–N bond to 1.233(6) Å. Another reduced bimetallic Fe–N 2 complex shows similarly lengthened N–N bond lengths …”

“…Synthetic Route toward 3 and 4 bimetallic Fe−N 2 complex shows similarly lengthened N−N bond lengths. 28 Independent routes to 3 and 4 were sought in order to circumvent the poor yields and separation issues encountered in the reactions detailed above and in Scheme 1. Conveniently, complex 3 can be isolated in quantitative yield by treatment of 2 with 1 equiv of IAd in THF at ambient temperatures (eq 1).…”