Studies on ansa-zirconocene–butadiene derivatives

Abstract

The new compounds [Zr{Me₂C(η-C₅H₄)₂}(cis-η-C₄H₆)] (2*), [Zr{Me₂C(η-C₅H₄)₂}Ph₂] (3), [Zr{Me₂C(C₅H₄)₂}(cis-η⁴-C₄H₄Me₂)] (4*), [Zr{Me₂C(η-C₅H₄)₂}(cis-η⁴-PhC₄H₄Ph)] (5), [Zr{Me₂C(η-C₅H₄)₂Cl}₂-μ-O] (6*), [Zr{Me₂C(η-C₅H₄)₂}{η³-C₄H₆B(C₆F₅)₃}] (7), [Zr{Me₂C(η-C₅H₄)₂}{exo-η³-C₄H₆B(C₆F₅)₃}PMe₃] (8*), [Zr{Me₂C(η-C₅H₄)₂}{endo-η³-C₄H₆B(C₆F₅)₃}C₆H₅N] (9*), and [Zr{Me₂C(η-C₅H₄)₂}{endo- and exo-η³-C₄H₆B(C₆F₅)₃}NC^tBu] (10a) and (10b) have been prepared. An asterisk indicates the crystal structure has been determined. The photoelectron spectra of 2 and 4 have been determined and assigned with the assistance of density functional methods. The factors relating to the relative stability of cis- and trans-butadiene structures for 2 and 4 are discussed.