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)

Abstract

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.