Iron(II), cobalt(II), and nickel(II) complexes of a cyclic (alkyl)(amino)carbene

摘要

Reactions of a sterically demanding cyclic (alkyl)(amino)carbene (CAAC) with FeCl_2(thf)_(1.5), CoBr_2, and NiBr_2(dme) afforded the complexes [FeCl(μ-Cl)(CAAC)]_2 (1), [CoBr(μ-Br)(CAAC)]_2 (2), and [NiBr(μ-Br)(CAAC)]_2 (3) in moderate yields. Compounds 1-3 were characterized by X-ray crystallography, ~1H 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.