Synthesis, chemical characterization and crystal structure of the anilinium bis(1,2-dithiooxalato-S,S')nickelate(II)

Purple single crystals of the complex (H3NC6H5)(2)[Ni(dto)(2)] (dto = S2C2O22- = 1,2-dithiooxalato-S,S') were grown in silica-hydrogel media. A microcrystalline powder of this compound was also obtained from an aqueous solution of anilinium hydrochloride and potassium bis(dithiooxalato)nickelate(II). The compound was characterized by elemental analysis, FT-IR spectroscopy and thermal techniques (TG/DTG and DTA). The crystal structure, determined by X-ray diffraction, consists of anilinium cations and [Ni(dto)(2)](2-) anions, with a near perfect square-planar environment of sulfur atoms around the nickel atom. Crystal cohesion is assumed by electrostatic interactions, an extensive three-dimensional network of hydrogen bonds and weak face-to-face pi-stacking interactions between the pi-systems of the aromatic cations.