Synthesis, X-ray crystal structure, and NMR characterisation of thiolate-bridged dinuclear Ni(II), Pd(II) and Pt(II) complexes of didentate ligands with NS-donor set

Thiolate-bridged dinuclear nickel(II), palladium(II) and platinum(II) complexes with N-(2-mercaptoethyl)-3,5-dimethylpyrazole (Hmed), [MCl(med)](2) (M = Ni (1), Pd (2), Pt (3)), have been synthesised and characterised by elemental analyses, conductivity, IR, electronic spectra and NMR spectroscopies. The crystal structure of 2 was determined by a single-crystal X-ray diffraction method. The structure consists of thiolate-bridged dinuclear units. Each Pd(II) atom is coordinated by a pyrazolic nitrogen, one chlorine and two bridging sulfur atoms. When the synthesis of complex 1 was carried out in acetonitrile and in the presence of oxygen, [NiCl3(Hdeds)] (4) was formed (deds = 1,1'-(dithiodiethylene)bis(3,5-dimethylpyrazole)). The crystal structure of this complex was also determined by single-crystal X-ray diffraction method. The structure consists of nickel(II) ions coordinated by three chloride ions and one pyrazolic nitrogen atom. Ligand deds is the result of the oxidation of N-(2-mercaptoethyl)-3,5-dimethylpyrazole (Hmed). (C) 2003 Elsevier Science B.V. All rights reserved.