Structure and characterization of hexakis(imidazole) cobalt(II) complexes: [Co(Im)6(OBz)2] and [Co(Im)6(mB)2] (Im = imidazole, OBz = benzoate, mB = p-methoxybenzoate)

The crystal and molecular structures of the complexes of [Co(Im)₆(OBz)₂] and [Co(Im)₆(mB)₂] (Im = imidazole, OBz = benzoate, mB = p-methoxybenzoate) have been determined by X-ray crystallography. The crystal structures are very similar and consist of discrete molecules of [Co(Im)₆(OBz)₂] and [Co(Im)₆(mB)₂], respectively. They both crystallize in the triclinic system, space group the former with lattice parameters a = 7.6934(3), b = 10.4518(5), c = 11.6088(5) Å, = 73.920(1), = 79.023(1), = 73.681(1)°, and Z = 1; the latter with a = 9.8336(3), b = 10.5509(2), c = 10.8889(3) Å, = 61.450(1), = 76.832(1), = 71.157(1)°, and Z = 1. The cobalt(II) ions have octahedral geometry with a CoN₆ chromophore. In the solid state, the complexes all form a three-dimensional network through N—H···O hydrogen bonds. The electronic spectra and IR spectra data are in agreement with the structural data.