用三异丁基铝改性甲基铝氧烷活化的茂金属催化剂——通过核磁共振光谱研究活性阳离子的转化

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

作者信息

Babushkin Dmitrii E, Brintzinger Hans H

机构信息

Boreskov Institute of Catalysis, Russian Academy of Science, Prospekt Akad.Lavrent'eva 5, 630090 Novosibirsk, Russia.

出版信息

Chemistry. 2007;13(18):5294-9. doi: 10.1002/chem.200601801.

DOI:10.1002/chem.200601801

PMID:17385201

Abstract

When triisobutylaluminum (AliBu(3)) is added to solutions containing methylaluminoxane (MAO) and rac-[Me(2)Si(ind)(2)ZrCl(2)] (ind: indenyl) in C(6)D(6), 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-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMe(2) (+)] to rac-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMeiBu(+)] and rac-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AliBu(2) (+)]. These species are unstable and release isobutene under formation of zirconocene hydrides.

摘要

当将三异丁基铝（AliBu(3)）添加到含有甲基铝氧烷（MAO）和rac-[Me(2)Si(ind)(2)ZrCl(2)]（ind：茚基）的C(6)D(6)溶液中时，核磁共振谱表明，甲基桥连的混合烷基铝二聚体Al(μ-Me)(2)Me(4-x)iBu(x)占主导。这些二聚体在异丁基部分转移的情况下与MAO反应，并促使最初占优势的阳离子三甲基铝加合物rac-[Me(2)Si(ind)(2)Zr(μ-Me)(2)AlMe(2) (+)]转化为rac-[Me(2)Si(ind)(2)Zr(μ-Me)(2)AlMeiBu(+)]和rac-[Me(2)Si(ind)(2)Zr(μ-Me)(2)AliBu(2) (+)]。这些物种不稳定，在形成氢化锆ocene的过程中释放出异丁烯。