Modification of methylaluminoxane-activated ansa-zirconocene catalysts with triisobutylaluminum -: Transformations of reactive cations studied by NMR spectroscopy

被引：33

作者：

Babushkin, Dmitrii E.

Brintzinger, Hans H.

机构：

[1] Russian Acad Sci, Boreskov Inst Catalysis, Novosibirsk 630090, Russia

[2] Univ Konstanz, Fachbereich Chem, D-78457 Constance, Germany

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2007年 / 13卷 / 18期

关键词：

aluminum alkyls; metallocenes; methylalummoxane; polymerization; structure-activity relationships;

D O I：

10.1002/chem.200601801

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

When triisobutylaluminum (AliBu(3)) is added to solutions containing methylaluminoxane (MAO) and rac-[Me2Si(ind)(2)ZrCl2] (ind: indenyl) in C6D6, NMR spectra show that methyl-bridged mixed-alkylaluminum dimers Al(mu-Me)(2)Me(4-x)iBu(x) predominate. These dimers react with MAO under partial transfer of isobutyl groups and induce a conversion of the initially prevailing cationic trimethylaluminum adduct rac-[Me2Si(ind)(2)Zr(mu-Me)(2)AlMe2+] to rac-[Me2Si(ind)(2)Zr(mu-Me)(2)AlMeiBu(+)] and rac-[Me2Si-(ind)(2)Zr(mu-Me)(2)AliBu(2)(+)]. These species are unstable and release isobutene under formation of zirconocene hydrides.

引用

页码：5294 / 5299

页数：6

共 44 条

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2-N

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