Functionalized dithioester and dithiocarbamato complexes of platinum(II) halides

Platinum dihalides react with the dithioester EtO2CCH2(CH3)NCS2Me (ESDTM) yielding the complexes Pt(ESDTM)X-2 and trans-Pt(ESDTM)(2)X-2 (X = Cl or Br). In the 1:2 adducts the ligand acts as monodentate through the thiocarbonyl sulfur, whereas it is S,S chelated in the Pt(ESDTM)X-2 species. These complexes release easily methyl halide either in solid or in solution to form species containing the related dithiocarbamato moiety (ESDT, EtO2CCH2(CH3)NCS2-). The first decomposition step in thermal degradation of the Pt(ESDTM)X-2 complexes involves evolution of one methyl halide molecule to form the related [Pt(ESDT)X](n) intermediate and leading finally to platinum metal. In the same conditions the trans-Pt(ESDTM)(2)X-2 complexes undergo demethylation of both ligand molecules, the Pt(ESDT)(2) intermediate being stable up to 250 degrees C. The dithioester adducts and the related degradation intermediates have been characterized by elemental analyses and IR and H-1 NMR spectroscopy. The complex behaviour in Various solvents has been described by proton NMR data.