New titanium and zirconium sandwich and half-sandwich complexes containing the C 5Me 4CH 2CH 2CHCH 2(Cp =) ligand

Abstract

The syntheses and characterization of new titanium and zirconium derivatives of the C 5Me 4CH 2CH 2CH 2(Cp +=) ligand are described. Reaction of LiCp = with ZrCl 4 in diethyl ether afforded the half-sandwich derivative [Zr 2( n-Cp 2)Cl 4( μ-Cl) 2] which is a precursor to the mixed-ring zirconocenes [Zr( n-Cp =( n-C 5H 5)Cl 2] and [Zr( n-Cp =) ( n-C 5Me 5)Cl 2]. Reaction of LiCp = with ZrCl 4 in toluene followed by crystallization in the presence of dme (1,2-dimethoxyethane) gave the unusual complex [Zr 2( n-Cp =) 2( μ-Cl) 3Li(dme)] (X-ray structure) in which a {Zr 2( n-Cp =) 2Cl 4( μm-Cl) 3} − moiety formally acts as a tetradentate ligand to a {Li(dme)} + fragment. Treatment of [TiCl 3(thf) 3] with LiCp = followed by HCL gave the half-sandwich titanium derivative [Ti( n-Cp =)Cl 3] and addition of one equivalent of LiCp = to a solution of [Ti(NBu t)Cl 2(4-NC 5H 4Bu t) 2] gave the corresponding imido complex [i( n-Cp =)(NBu t)Cl(4-NC 5H 4 Bu t)] in quantitative yield.