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

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 [(PDI)Co(μ-CN)(PMe)][OTf] ([CoCN]) 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 [(PDI)Co(μ-CH)(PMe)][OTf] ([CoCH]) is the first structurally characterized dicobalt complex with a bridging methyl group.