Ligand properties of phosphinito platinum complexes: 31P and 195Pt nuclear magnetic resonance studies and the crystal and molecular structure of [Cl(Et3P)Pt(μ-PPh2O)2Pt(PEt3)2][BF4]

Reaction of sodium hydride in tetrahydrofuran with the hydrogen-bonded phosphinito complex, [PtCl(PEt 3 ){(PPh 2 O) 2 H}], gives a solution of the salt, [PtCl(PEt 3 ){(PPh 2 O) 2 Na}], which is a precusor to synthesis of other bimetallic derivatives, [PtCl(PEt 3 ){(μ-PPh 2 O) 2 Q}] n+ : n = 0, Q = Rh(COD) or Ir(COD); n = 1, Q = Pd(PEt 3 ) 2 or Pt(PEt 3 ) 2 . Detailed 31 P and 195 Pt nmr studies are reported for these and related examples including a titanium complex (n = 0, Q = Ti(acac)Cl 2 ) synthesised by direct reaction of [PtCl(PEt 3 ){(PPh 2 O) 2 H}] with [TiCl 2 (acac) 2 ]. The diplatinurn complex, [Cl(PEt 3 )Pt(μ-PPh 2 O) 2 Pt(PEt 3 ) 2 ][BF 4 ] crystallizes in the monoclinic space group P2 1 /n, with a = 13.018(2), b = 34.205(9), c = 11.279(2) Å, β = 91.71(2)°. A complete X-ray diffraction study shows that the two platinum centres are significantly non-planar and are linked by the phosphinito ligands to form a six-membered ring in a boat conformation with phosphorus and oxygen atoms forming the prows of the boat.