Synthesis and 13C NMR study of the triangulo-clusters [Pt3(μ-CO)3−n(μ-SO2)n(PR3)3] (n=0–3)

[Pt3(μ-CO)3(PPh3)3] was prepared in high yield by the reaction of [Pt3(μ-CO)3(PPh3)4] with H2O2. The carbonyl ligands in [Pt3(μ-CO)3(PR3)3] (PR3=PPh3, PPh2Bz, PCy3, PiPr3) may be completely replaced by sulfur dioxide to give [Pt3(μ-SO2)3(PR3)3] or partially by one SO2 to give [Pt3(μ-CO)2(μ-SO2)(PR3)3] (PR3=PCy3 and PiPr3). On the other hand, the addition of one molar equivalent of carbon monoxide to [Pt3(μ-SO2)3(PR3)3] (PR3=PCy3; PiPr3) gave the complexes [Pt3(μ-CO)(μ-SO2)2(PR3)3]. Complete simulation of the 13C NMR spectra could be achieved with the help of 195Pt NMR data.