Facile and reversible displacement of η-C 5 H 5 from Zr by organolithiums; formation of (η 5 -cyclopentadienyl) trialkylzirconiums and their reactions eith electrophiles and alkenes

Treatment of [Zr(η- C5H5)2Cl2] with 3 equiv. of BunLi gives a 1 : 1 mixture of [Zr(η- C5H5) Bun3] and Li(C5H5), which reacts with HCl or I2 to give n-butane and [Zr(η- C5H5)2Cl2] or BunI and [Zr(η- C5H5)2I2], respectively, while the reaction of [Zr(η- C5H5)2Cl2] with 3.3 equiv. of C6H12Li and hex-1-ene provides a novel zirconate best represented by 3.