Synthesis and structural characterization of the tetraruthenium cluster complexes [Ru4(µ-H)4(CO)10(L–L)](L–L = diphosphine)

Abstract

The clusters [Ru₄(µ-H)₄(CO)₁₀{(S)-(–)-binap}]1 and [Ru₄(µ-H)₄(CO)₁₀{(S)-(–)-mobiph}]2 containing the atropoisomeric diphosphine ligands (S)-(–)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) and (S)-(–)-2,2′-bis(diphenylphosphino)-6,6′-dimethoxy-1,1′-biphenyl (mobiph) have been synthesized via direct reaction of [Ru₄H₄(CO)₁₂] in toluene at 150 °C with a two-fold excess of the diphosphine under hydrogen pressure. Their molecular and crystal structures have been determined by single-crystal X-ray diffraction: both crystallize in the orthorhombic system, space group P2₁2₁2₁, Z= 4; a= 13.009(7), b= 14.357(2), c= 29.109(7)Å for 1; a= 12.108(8), b= 15.845(3), c= 28.241(5)Å for 2. In both complexes the diphosphine ligand chelates the Ru atom involved in three hydride bridges.