SYNTHESIS, REACTIONS, AND P-31 NMR ANALYSIS OF (DIPHOSPHINE)PLATINUM DITHIOLATES

The reaction between (diphosphine)PtCl2 (diphosphine = dppm, dppe, dppp, dppb, dcpe, depe) and bifunctional thiols (1,2-ethanedithiol, 1,3-propanedithiol, 1,2-benzenedithiol) in acetone or CH2Cl2 gives the corresponding dithiolate complexes (1-18) in the presence of a base. These thiolato complexes have been isolated as crystalline solids in 57-88% yields and were characterized by H-1, C-13, and P-31 NMR spectroscopy. The P-31 chemical shifts of these complexes are dependent on both the nature of the diphosphine and the chelating nature of the dithiolato ligand. Treatment of (depe)Pt(SC6H4-o-S) (15) and the analogous dcpe complex (18) with 1 equiv of MeI, allyl chloride, or Me3OBF4 gave the corresponding sulfur-monoalkylated product. Reaction of Cr(nbd)(CO)4 with (depe)PtSC6H4-o-S (15) gave (depe)Pt(SC6H4-o-S)(Cr(CO), (22) in 64% yield.