Two-Electron Reduction of a Vanadium(V) Nitride by CO to Release Cyanate and Open a Coordination Site

Abstract

Generation of the nitrido functional group is commonly achieved by treatment of metal complexes with azide sources and is fostered by N2 extrusion.1 The analogous transformation involving isocyanate and production of CO is less well documented. A previous study by Fickes et al. showed that the 1e reduction of a niobium(IV) isocyanate complex (OCN)Nb(N[t-Bu]Ar)3 (1-Nb(NCO), Ar = 3,5-Me2C6H3) results in formation of a nucleophilic, anionic terminal nitride complex [NNb(N[t-Bu]Ar)3]– (1-NbN–) with concomitant evolution of CO.2 This, to the best of our knowledge, is the only example of terminal metal nitride derivation from an isocyanate ligand (Scheme 1A).2,3 Curious as to the generality of this reductive decarbonylation, we sought to synthesize the analogous vanadium isocyanate complex (OCN)V(N[t- Bu]Ar)3 (1-V(NCO)) to compare its reactivity with that of 1- Nb(NCO).