Iron(II), Cobalt(II), and Nickel(II) Complexes of a Cyclic (Alkyl)(amino)carbene

Reactions of a sterically demanding cyclic (alkyl)(amino)carbene (CAAC) with FeCl2(thf)(1.5), CoBr2, and NiBr2(dme) afforded the complexes [FeCl(-Cl)(CAAC)](2) (1), [CoBr(-Br)(CAAC)](2) (2), and [NiBr(-Br)(CAAC)](2) (3) in moderate yields. Compounds 1-3 were characterized by X-ray crystallography, H-1 NMR, and UV/Vis spectroscopy. Dimeric, halide-bridged structures were observed in the solid state, in which the metal atoms are coordinated in a distorted tetrahedral fashion by the CAAC and three halide ligands. The solution magnetic moments in THF and dichloromethane indicate a high-spin electronic configuration.