Bimetallic systems. Part 3. Complexes containing the ligand bis(diphenylphosphino)methane bridging from the platinacycle PtCH2CH2CH2CH2 to another metal

Abstract

The metallacycle [graphic omitted]H₂)(dppm-PP′)](5)(dppm = Ph₂PCH₂PPh₂) is made from [PtCl₂(dppm-PP′)] and Li(CH₂)₄Li in diethyl ether. Complex (5) rapidly reacts with dppm to give [[graphic omitted]H₂)(dppm-P)₂](6) which contains monodentate dppm ligands and is remarkably stable with respect to dissociation. It is shown that (6) is a convenient starting material for making bimetallic species. Thus treatment of (6) with [{Agl(PPh₃)}₄] gives the neutral complex [([graphic omitted]t(µ-dppm)₂Agl]; treatment with Ag[PF₆] or [AuCl(PPh₃)] gives the salts [([graphic omitted]t(µ-dppm)₂M]⁺X^–(M = Ag, X = PF₆; M = Au, X = Cl) and treatment with [MCl(CH₃)(cod)](cod = cyclo-octa-1,5-diene) gives the dative-bonded species [([graphic omitted]t(µ-dppm)₂M(CH₃)]Cl (M = Pt or Pd). Microanalytical data, solution conductivity data, and ¹H-{³¹P}, ³¹P-{¹H}, and ¹⁹⁵Pt-{¹H} n.m.r. data are given and discussed.