PLATINUM (II)-COMPLEXES WITH SULFER-FUNCT IONALIZED ALKENYL LIGANDS

trans-[PtClHL2] (L=PEt3, PPh3) reacts with thioalkynes RSC-CR' (R=Me, Ph; R'=Ph, C5H11) to give the 1-thioalk-1-enyl complexes cis-[Pt{(E)-C (SR)=CHR'}ClL2 (1a: L=PEt3, R/R'=Me/Ph; 2d: L=PPh3, R/R'=Me/Ph) and tr ans-[Pt{(E)-C(SR)=CHR'}ClL2 (1c: L=PEt3, R/R'=Me/C5H11; 2a: L-PPh3, R/ R'=Me/Ph; 2b: L=PPh3, R/R'=Me/C5H11). PhSC=CSiMe3 reacts with trans-[P tClH(PPh3)(2) with splitting off the trimethylsilyl group to generate trans-[Pt{(E)-C(SPh)=CH2}Cl (PPh3)(2)] (2c). Complex 1a isomerizes in boiling CDCl3 to form trans-[Pt{(E)-C(SMe)=CHPh} Cl(PEt3)(2)] (1b). Al l compounds were characterized by microanalyses and H-1-, C-13- and P- 31-NMR spectroscopy. The structures of cis-[Pt{(E)-C(SMe)=CHPh}Cl(PEt3 )(2)] (1a) and trans-[Pt{(E)-C(SMe)=CHPh)Cl(PPh3)(2)] . CHCl3 (2a) hav e been determined by X-ray diffraction. Both complexes are square-plan ar; the P1-Pt-P2 angle in 1a is widened (99.03(5)degrees). The planes of the vinyl ligand and the complex are nearly perpendicular (interpla nar angles: 88.1(1)degrees (1a), 84.9(2)degrees (2a)). In complex 2a a weak Pt-S interaction is observed (d(Pt ... S)=3.008(2) Angstrom).