SILANOLATO COMPLEXES OF TITANIUM AND ZIRC ONIUM - THE CRYSTAL-STRUCTURES OF CP2TICL(OSIPH3) AND CP2ZRCL(OSIPH3)

The title compounds have been prepared by the reaction of Cp2MCl2 (M = Ti, Zr) with triphenylsilanole in diethylether in the presence of pip eridine. They form only sparingly moisture sensitive orange (Ti) or co lourless (Zr) crystal needles, which were characterized by X-ray cryst allography. Cp2TiCl(OSiPh3): Space group P2(1)/n, Z = 4, structure sol ution with 3961 observed unique reflections, R = 0.057. Lattice dimens ions at 20-degrees-C: a = 1029.6, b = 1719.3, c = 1388.9 pm, beta = 10 0.69-degrees. The compound forms monomeric molecules with bond lengths TiO of 184.2 pm, SiO of 161.5 pm, and a TiOSi bonding angle of 164.5- degrees. Cp2ZrCl(OSiPh3): Space group P3BAR, Z = 18, structure solutio n with 2799 observed unique reflections, R = 0.047. Lattice dimensions at -20-degrees-C: a = b = 3518, c = 1058.3 pm. The structure consists of three symmetry-independent monomeric molecules, which differ only slightly. The bond lengths are (in average): ZrO 196.4 pm, SiO 162.1 p m, the ZrOSi bond angle is 173.7-degrees.