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

Three salts of inorganic dithiooxalato complexes, (Ph(4)P)(2)[Ni(dto)( 2)] (1), (Ph(4)P)(2)[Pd(dto)(2)] (2) and (Ph(4)P)(2)[Pt(dto)(2)] (3), where Ph(4)P(+) is the tetraphenylphosphonium cation and dto(2-) is th e 1, 2-dithiooxalato-S,S' ligand, were synthesized and characterized b y elemental analysis, IR and UV-vis spectroscopies, thermal analysis ( TG, DTG and DTA) and X-ray diffraction techniques. The IR and UV-vis s pectra support the presence of the organic cation and the complex anio ns. The three compounds are isostructural and crystallize in the tricl inic space group P ($) over bar 1. The thermal analytical data show th at the starting compounds and the surrounding atmosphere significantly influence the course of the decomposition reactions, as well as the f inal products. They were examined by elemental analysis and X-ray powd er diffractometry. In an argon-oxygen atmosphere, a mixture of nickel (II, III) oxides and nickel (II) sulphide for 1, metallic palladium fo r 2 and platinum (0) for 3 were obtained, whereas under argon nickel s ulphides, a mixture of Pd/PdS and metallic platinum were identified as the final products.