Unusual cyanide and methyl binding modes at a dicobalt macrocycle following acetonitrile C–C bond activation

Abstract

This communication describes the C–C bond activation of acetonitrile and the trapping of the methyl and cyanide fragments by macrocyclic, dicobalt complexes. Both products display unique structural features as a result of the constraints imposed by the macrocycle. The bridged species [(³PDI₂)Co₂(μ-CN)(PMe₃)₂][OTf] ([Co₂CN]⁺) exhibits atypical Co–CN–Co binding, and upon either phosphine dissociation or oxidation, the flexible ligand framework is able to switch between different binding modes of μ-cyanide. Further, the bridging methyl species [(³PDI₂)Co₂(μ-CH₃)(PMe₃)][OTf] ([Co₂CH₃]⁺) is the first structurally characterized dicobalt complex with a bridging methyl group.