Dichloro(methyl) silyl-substituted cyclopentadienyl titanium complexes

The synthesis of (C5H4)(SiMeCl2)(SiMe3) is described. The reaction of a dichloromethane solution of this compound with one equivalent of titanium tetrachloride leads to the monocyclopentadienyl complex [TiCl3{η5-C5H4(SiMeCl2)}]. Treatment of this complex with the lithium amides LiN(SiMe3)2 and LiNHtBu affords [TiCl2{N(SiMe3)2}{η5-C5H4(SiMeCl2)}] and [TiCl2{η5-C5H4[SiMeCl(η-NtBu)]}], respectively. Alkylation of the trichlorotitanium derivative with 1.5 equivalents of Mg(CH2C6H5)2(THF)2 leads to the tribenzyl derivative [Ti(CH2C6H5)3{η5-C5H4(SiMeCl2)}]. Hydrolysis of the trichloro- and tribenzyl-complexes leads to the μ-oxo dititanium compounds [TiX2μ-{η5-C5H4(η-OSiMeCl)}]2 (X=Cl, CH2Ph). All of the new complexes were characterized by elemental analysis and NMR spectroscopy.We are grateful to the DGICYT (Project PB-92-0178-C) and CAM (I + D 0034/94) for financial support.\ud B.R. acknowledges Universidad de Alcalá de Henares for support provided (Project 042/95

Dicyclopentadienyl zirconium and hafnium complexes with the bridged (dimethylsilanodiyl)dicyclopentadienyl [(SiMe2)(η5-C5H4)2]2 ligand. X-ray molecular structure of [Zr{(SiMe2)(η5-C5H4)2}(CH2Ph)]2(μ-O)

Reaction of the bridged (dimethylsilanediyl)dicyclopentadienyl dilithium salt [(SiMe2)(C5H4)2Li2] with MCl4, in toluene, gave the zirconium and hafnium complexes [M{(SiMe2)(η5-C5H4)2}Cl2] [M=Zr (1), Hf (2)]. Addition of two equivalents of M′R (M′=MgCl, R=CH3; M′=Li, R=CH2CMe2Ph; M′=MgBz, R=CH2Ph) to toluene or diethyl ether solutions of [M{(SiMe2)(η5-C5H4)2}Cl2] afforded the dialkyl derivatives [M{(SiMe2)(η5-C5H4)2}R2] [R=CH3, M=Zr (3), Hf (4); R=CH2CMe2Ph, M=Zr (5), Hf (6); R=CH2Ph, M=Zr (7)]. Compound 1 reacted with LiMe and Mg(CH2Ph)2(THF)2 in the presence of a stoichiometric amount of water to give the μ-oxo derivatives [Zr{(SiMe2)(η5-C5H4)2}R]2(μ-O) [R=CH3 (8), CH2Ph (9)]. The X-ray molecular structure of [Zr{(SiMe2)(η5-C5H4)2}(CH2Ph)]2(μ-O) (9) has been determined by diffraction methods. Its most remarkable feature is the planarity of the BzZrOZrBz and the linearity of the ZrOZr systems.We acknowledge the Dirección General de Investigación Científica y Técnica (Spain) for financial support of this research (Project PB97-0776)