부산대학교 도서관

In reactions of the zirconocene derivative Cp2ZrC(SiMe3)&dbd;C(SiMe3)(THF) with ketones and aldehydes the influence of the various substituents of the carbonyl compounds upon the formation of different products was investigated. Formaldehyde reacts by an insertion of the carbonyl unit into a Zr−C bond to give a metallacycle which is additionally stabilized by the formation of a coordination dimer [Cp2ZrOCH2C(SiMe3)&dbd;C(SiMe3)]2 (1). Benzaldehyde yields a monomeric metallacycle Cp2ZrOCHPhC(SiMe3)&dbd;C(SiMe3) (2). Complex 2 is less stable than 1, and at higher temperatures it loses half of its moiety Me3SiC2SiMe3, leaving {[Cp2ZrOCHPhC(SiMe3)&dbd;C(SiMe3)][Cp2Zr(η²-O&dbd;CHPh)]} (3). Benzophenone gives no insertion, and the monomeric η²-ketone complex Cp2Zr(THF)(η²-O&dbd;CPh2) (4) was obtained.