SILYL AND SILOXANEDIYL CYCLOPENTADIENYL TITANIUM AND ZIRCONIUM COMPLEXES - SYNTHESIS AND REACTIVITY - X-RAY MOLECULAR-STRUCTURE OF [ZR(ETA(5)-C5H4SIME2(MU-OH))(MU-CL)CL-2](2)

Chloro(dimethyl)silyl-eta(5)-cyclopentadienyl group 4 metal complexes of the type [M(mu(5)-C5H4SiMe2 Cl)Cl-3] (M = Ti 1, Zr 2) react with th allium salts Tl(C5H4R) (R = H, SiMe3) to give mixed dicyclopentadienyl derivatives [M(eta(5)-C5H4R)(eta(5)-C5H4SiMe2Cl)Cl-2], (M = Ti, R = H 3, R = SiMe3 4; M = Zr, R = H 5, R = SiMe3 6) in high yield. Hydrolys is of complexes 3 and 4 affords the dinuclear complexes (5)-C5H4R)Cl-2 ](2){mu(5)-[(eta(5)-C5H4SiMe2)(2)O]} (R = H 7, R = SiMe3 8) containing a siloxanyl bridge, by elimination of two equivalents of HCl. Reactio ns of complexes 1 with hydroxo containing reagents such as anhydrous L iOH and SiPh2(OH)(2) give the derivatives [Ti(eta(5)-C5H4SiMe2Cl)Cl-2] (2)(mu-O)], 9 and Ti[mu-(mu(5)-C5H4SiMe2OSiPh2-eta(1)-O)]Cl-2, 10 iden tified by analytical, spectrometric and spectroscopic data. Treatment of analogous complex 2 with water produces the dimeric monocyclopentad ienyl zirconium trichloride adduct [Zr(eta(5)-C5H4SiMe2OH)Cl-3](2), 11 . Compound 11 has been characterized by X-ray crystallography. (C) 199 8 Elsevier Science Ltd. All rights reserved.