TRIPHENYLSILOXY COMPLEXES - A NOVEL COMPOUND CONTAINING A MO(VI)-P BOND - MOO2(OSIPH3)2(PPH3)

Triphenylsiloxy complexes have been synthesized through direct silylation of silver metalates by triphenylchlorosilane. The Mo dioxo complex MoO2(OSiPh3)2 (1) is tetrahedral and crystallizes in the Fdd2 space group with a = 19.556(7) angstrom, b = 34.187(4) angstrom, c = 9.748(5) angstrom, V = 6517.3(3.6) angstrom3, and D(calcd) = 1.38 g/cm3 for Z = 8; final residuals R = 4.4% and R(w) = 4.4%. An interesting compound, MoO2(OSiPh3)2(PPh3) (2), containing the first Mo(VI)-phosphine bond was also synthesized in this study and characterized by single-crystal X-ray diffraction. X-ray crystallographic data for compound 2: a = 18.498(4) angstrom, b = 10.818(3) angstrom, c = 24.844(3) angstrom, beta = 107.08(1)degrees, V = 4753(2) angstrom3, D(calc) = 1.315 g/cm3 for Z = 4; final residuals R = 5.2% and R(w) = 5.6% for 1236 (I > 3sigma(I)) reflections and 194 variables. Compound 2 has a distorted trigonal bipyramidal structure with a Mo-P bond length equal to 2.759 angstrom. The preparation and a single-crystal X-ray structure of VO(OSiPh3)3 are also reported.