Coordinatively unsaturated complexes [M2(CO)4(μ-H)(μ-PtBu2)(μ-Ph2PCH2PPh2)] (MFe, Ru): synthesis and crystal structures of [Fe2(CO)4(μ-H)(μ-SO)(μ-PtBu2)(μ-Ph2PCH2PPh2)] and [Ru2(CO)4(μ-H)(μ-SO2)(μ-PtBu2)(μ-Ph2PCH2PPh2)]

[Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1a) reacts with elemental sulfur to give [Fe2(CO)4(μ-H)(μ-S)(μ-PtBu2)(μ-dppm)] (2a) (dppm=Ph2PCH2PPh2). The reaction of 1a with CCl4 or CHCl3 affords spontaneously in nearly quantitative yield [Fe2(CO)4(μ-Cl)(μ-PtBu2)(μ-dppm)] (3a). [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1b) reacts with SO2 in THF under normal conditions to [Ru2(CO)4(μ-H)(μ-SO2)(μ-PtBu2)(μ-dppm)] (5b). 5b is also formed by oxidation of the sulfido ligand in [Ru2(CO)4(μ-H)(μ-S)(μ-PtBu2)(μ-dppm)] (2b) by means of 3-chloroperoxybenzoic acid or H2O2 as oxidizing reagent. As the primary oxidation products of 2a or 2b the sulfur monoxide complexes [M2(CO)4(μ-H)(μ-SO)(μ-PtBu2)(μ-dppm)] (MFe, 4a; MRu, 4b) are obtained by using 3-phenyl-2-(phenylsulfonyl)-oxaziridine as oxidizing reagent. The molecular structures of 4a and 5b were confirmed by crystal structure analyses.