Herein we present the first double deprotonation of acetonitrile (CH3CN) using two equivalents of a bimetallic iron-aluminium complex. The products of this reaction contain an exceeding simple yet rare [CHCN]2- 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 [CH2CN]- 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.[1, 2] The isolation of a [CHCN]2- dianion through simple deprotonation of CH3CN also offers the possibility of establishing a broader chemistry of this motif.
The double deprotonation of CH3CN was achieved using an iron‐aluminium complex, yielding products containing a simple yet rare [HC=C=N]2− dianion, characterised by X‐ray crystallography. DFT calculations suggest that the mechanism proceeds via a stepwise double deprotonation of the substrate by two equivalents of the bimetallic complex, with the intermediacy of a [NCCH2]− anion, which was observed spectroscopically in situ.
Keywords: Aluminium; C−H Activation; Dianions; Iron; Nitriles.
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