Synthesis, Characterization and Hydrolysis of Osmium Tetraphosphorus Complexes

The reaction of [CpOs(PPh 3 ) 2 Cl] (1) with one equivalent of white phosphorus in the presence of AgOTf (OTf = triflate, OSO 2 CF 3 ) as chloride scavenger affords the stable metal complex [CpOs(PPh 3 ) 2 (η 1 -P 4 )]OTf (2), which contains the tetrahedral P 4 η 1 -bond to the CpOs(PPh 3 ) 2 metal fragment. Addition of [CpRu(PPh 3 ) 2 (OTf)] to 2 yields the heterobimetallic species [{CpRu(PPh 3 ) 2 }[CpOs(PPh 3 ) 2 )}(μ,η 1:1 -P 4 )](OTf) 2 (3), in which the tetrahedral P 4 is bound to two different metal fragments through two phosphorus atoms. The compounds have been characterized by elemental analysis, IR and NMR spectroscopy, and their crystal structures have been determined by X-ray diffraction. The coordinated P 4 , at variance with the free ligand, reacts with an excess amount of water in thf under mild conditions to yield several products, most of which have been characterized.