Synthesis, structure and substitution reactions of the binuclear phosphido-bridged complex

Article abstract of DOI:10.1016/0022-328X(94)05152-2

Bimetallic phosphido-bridged complexes CpW(CO)3(μ-PPh2)W(CO)5 (1) and (2) were prepared by the reaction of CpW(CO)3PPh2 with W(CO)5THF.The structures of 1 and 2 were determined by single X-ray diffraction.Crystal data for 1: C25H15O8PW2, space group, P2₁/n with a = 9.6234 (18) Angstroem, b = 12.4514(20) Angstroem, c = 20.750(4) Angstroem, β = 98.445(14) deg, V = 2459.4(7) Angstroem³, Z = 4.The structure was refined to R = 0.031 and R_w = 0.035.Crystal data for 2: C24H15O7PW2, space group, P2₁/n with a = 14.4801(11) Angstroem, b = 11.6628(12) Angstroem, c = 14.732(3) Angstroem, β = 97.893(11) deg, V = 2464.3(6) Angstroem³, Z = 4.The structure was refined to R = 0.054 and R_w = 0.050.The long distance between W and W (4.5096(11) Angstroem) in 1 indicates that no metal-metal bond exists in the complex.The W-W distance was 3.1942(12) Angstroem in 2, indicative of a W-W bond.Substitution reactions between 2 and Lewis bases L (L = PPh3, PEt3, P(OMe)3) produced (3) with L regiospecifically and stereospecifically coordinating to the W(CO)4 moiety trans to the phosphido bridge.The structure of (3a) was determined by single-crystal X-ray diffraction.Crystal data for 3a: C26H24O9P2W2, space group, P2₁ with a = 9.2231(16) Angstroem, b = 15.868(3) Angstroem, c = 10.745(3) Angstroem, β = 110.282(18) deg, V = 1475.1(5) Angstroem³, Z = 2.The structure was refined to R = 0.037 and R_w = 0.039.Under similar reaction conditions, complex 1 did not react with L.Keywords: Tungsten; Group 6; Carbonyl; ?-bonding; Cyclopentadienyl; Bridging ligand