Crystal structure of bis(3-bromopyridine-kappa N)bis(O-ethyl dithiocarbonato-kappa(2) S, S ')-nickel(II)

In the title molecular complex, [Ni(C3H5OS2)(2)(C5H4BrN)(2)], the Ni2+ cation is located on a centre of inversion and has a distorted octahedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C-S bond lengths of the thiocarboxylate group are indicative of a delocalized bond and the O-Csp(2) bond is considerably shorter than the O-Csp(3) bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C = O+ unit and a negative charge on each of the S atoms. The packing of the molecules is stabilized by C-H center dot center dot center dot S and C-H center dot center dot center dot pi interactions. In addition, pi-pi interactions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) angstrom] are also present. In the crystal structure, molecules are arranged in rows along [100], forming layers parallel to (010) and (001).