NEW TITANIUM AND ZIRCONIUM SANDWICH AND HALF-SANDWICH COMPLEXES CONTAINING THE C(5)ME(4)CH(2)CH(2)CH=CH2(CP(=)) LIGAND

The syntheses and characterization of new titanium and zirconium deriv atives of the C(5)Me(4)CH(2)CH(2)CH=CH2(Cp(=)) ligand are described. R eaction of LiCp(=) with ZrCl4 in diethyl ether afforded the half-sandw ich derivative [Zr-2(eta-Cp(=))(2)Cl-4(mu-Cl)(2)] which is a precursor to the mixed-ring zirconocenes [Zr(eta-Cp(=))(eta-C5H5)Cl-2] and [Zr( eta-Cp(=))(mu-C(5)Me(5))Cl-2]. Reaction of LiCp(=) with ZrCl4 in tolue ne followed by crystallization in the presence of dme (1,2-dimethoxyet hane) gave the unusual complex [Zr-2(eta-Cp(=))(2)Cl-2(mu-Cl)(3)Li(dme )] (X-ray structure) in which a {Zr-2(eta-Cp(=))(2)Cl-4(mu-Cl)(3)}(-) moiety formally acts as a tetradentate ligand to a {Li(dme)}(+) fragme nt. Treatment of [TiCl3(thf)(3)] with LiCp(=) followed by HCl gave the half-sandwich titanium derivative [Ti(eta-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 [Ti(eta-Cp(=))(NBu(t) )Cl(4-NC(5)H(4)Bu(t))] in quantitative yield.