Double Deprotonation of CHCN by an Iron-Aluminium Complex.

Herein we present the first double deprotonation of acetonitrile (CHCN) using two equivalents of a bimetallic iron-aluminium complex. The products of this reaction contain an exceeding simple yet rare [CHCN] dianion moiety that bridges two metal fragments. DFT calculations suggest that the bonding to the metal centres occurs through heavily polarised covalent interactions. Mechanistic studies reveal the intermediacy of a monomeric [CHCN] complex, which has been characterised in situ. Our findings provide an important example in which a bimetallic metal complex achieves a new type of reactivity not previously encountered with monometallic counterparts. The isolation of a [CHCN] dianion through simple deprotonation of CHCN also offers the possibility of establishing a broader chemistry of this motif.