Hydrogenolysis of tetra(allyl)tungsten in the presence of tertiary phosphines: synthesis of tris(dmpm)tungsten (0)

Article abstract of DOI:10.1016/0022-328X(95)05500-O

Reaction of W(η³-C3H5)4 with PMe2Ph and Me2PCH2PMe2 (dmpm) under 1 atm of H2 in toluene at 110-120 deg C yielded WH4(PMe2Ph)4 and W(dmpm)₃, respectively.Spectroscopic studies on the hydrogenolysis of W(η³-C3H5)4 in the presence of tertiary phosphines PEt3, PMePh2, and PPh3 were consistent with formation of the tungsten phosphine hydride complexes WH6(PEt3)3, WH4(PMePh2)4 and WH6(PPh3)3.W(η³-C3H5)4 has advantages over similar hydrogenolysis of WMe6 in that W(η³-C3H5)4 is considerably more thermally and air stable.Pyrolysis of WH4(PMePh2)4 at 400 deg C under a hydrogen flow yielded a shiny tungsten powder contaminated by hydrocarbon residues.Keywords: Tungsten; Phosphines; Hydrides; Hydrogenolysis; Hydrogenation