Two-coordinate Fe0 and Co0 complexes supported by cyclic (alkyl)(amino)carbenes

Abstract

The CAAC [CAAC=cyclic (alkyl)(amino)carbene] family of carbene ligands have shown promise in stabilizing unusually low-coordination number transition-metal complexes in low formal oxidation states. Here we extend this narrative by demonstrating their utility in affording access to the first examples of two-coordinate formal Fe0 and Co0 [(CAAC)2M] complexes, prepared by reduction of their corresponding two-coordinate cationic FeI and CoI precursors. The stability of these species arises from the strong σ-donating and π-accepting properties of the supporting CAAC ligands, in addition to steric protection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.