Tetraphenylphosphonium 1,2-dithiooxalato-s,s′ complexes of nickel(II), palladium(II) and platinum(II). Synthesis, chemical characterization, spectroscopic and x-ray studies, and thermochemistry

Abstract

Three salts of inorganic dithiooxalato complexes, (Ph 4P) 2[Ni(dto) 2] ( 1), (Ph 4P) 2[Pd(dto) 2] ( 2) and (Ph 4P) 2[Pt(dto) 2] ( 3), where Ph 4P + is the tetraphenylphosphonium cation and dto 2− is the 1,2-dithiooxalato- S, S′ ligand, were synthesized and characterized by elemental analysis, IR and UV-vis spectroscopies, thermal analysis (TG, DTG and DTA) and X-ray diffraction techniques. The IR and UV-vis spectra support the presence of the organic cation and the complex anions. The three compounds are isostructural and crystallize in the triclinic space group P 1 . The thermal analytical data show that the starting compounds and the surrounding atmosphere significantly influence the course of the decomposition reactions, as well as the final products. They were examined by elemental analysis and X-ray powder diffractometry. In an argon-oxygen atmosphere, a mixture of nickel(II, III) oxides and nickel(II) sulphide for 1, metallic palladium for 2 and platinum(0) for 3 were obtained, whereas under argon nickel sulphides, a mixture of Pd/PdS and metallic platinum were identified as the final products.