New titanium and zirconium sandwich and half-sandwich complexes containing the C5Me4CH2CH2CH=CH2(Cp ⁼) ligand

Abstract The syntheses and characterization of new titanium and zirconium derivatives of the C 5 Me 4 CH 2 CH 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 5 H 5 )Cl 2 ] and [Zr( n -Cp = ) ( n -C 5 Me 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) 3 Li(dme)] (X-ray structure) in which a {Zr 2 ( n -Cp = ) 2 Cl 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 5 H 4 Bu t ) 2 ] gave the corresponding imido complex [i( n -Cp = )(NBu t )Cl(4-NC 5 H 4 Bu t )] in quantitative yield.