The di-µ-bis(diphenylphosphino)methane-µ-hydrido-bis[methylplatinum(II)] cation: synthesis, molecular structure, and chemical properties

Abstract

The binuclear title complex [Pt₂Me₂(µ-H)(µ-dppm)₂][PF₆], dppm = Ph₂PCH₂PPh₂, has been prepared and characterized by ^lH and ³¹P n.m.r. spectroscopy and by an X-ray structure determination. Crystals are monoclinic, with space group P2₁/c, a= 10.640(3), b= 20.341(3), c= 23.201(3)Å, β= 91.88(2)° and Z= 4. The structure has been solved by the heavy-atom method and refined to R= 0.053 for 5 374 reflections withl 3σ(I). The cation has the ‘A-frame’ structure with a Pt–Pt separation of 2.932(1)Å; a closed three-centre two-electron Pt₂(µ-H) bonding system is proposed. The complex undergoes slow reductive elimination of methane induced by added PMe₂Ph and is photochemically decomposed, but it has high thermal stability.