用于烯烃聚合的立体定向八面体基团 4 双（苯酚）醚配合物。

Stereospecific octahedral group 4 bis(phenolate) ether complexes for olefin polymerization.

机构信息

Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.

出版信息

J Am Chem Soc. 2010 Apr 28;132(16):5566-7. doi: 10.1021/ja100627x.

PMID:20359183

Abstract

Octahedral group 4 bisphenolate ether complexes, activated by methylaluminoxane, are highly active and stereospecific alpha-olefin polymerization catalysts. X-ray crystallographic analysis reveals the Zr and Hf complexes to be closely isostructural; the bond lengths of the Hf complex are slightly shorter, but the maximum deviation is only 0.062 A. Despite the structural similarity of the Hf and Zr complexes, the Hf complexes generate more highly stereoselective catalysts. In addition to the influence of the transition metal, the structure of the ligand has a large influence on the stereospecificity. Bis-tert-butyl phenyl substituted complexes of Hf and Zr, when activated by MAO at 50-80 degrees C, generate high molecular weight polypropylene (M(n) = 130,000-360,000 g/mol) with isotacticities [mmmm] > 97% and melting points as high as 165 degrees C.

摘要

八面体基团 4 双酚醚配合物，用甲基铝氧烷激活，是高效和高立体定向的α-烯烃聚合催化剂。X 射线晶体学分析表明，Zr 和 Hf 配合物具有非常相似的结构；Hf 配合物的键长稍短，但最大偏差仅为 0.062Å。尽管 Hf 和 Zr 配合物具有结构相似性，但 Hf 配合物生成了更具高立体选择性的催化剂。除了过渡金属的影响外，配体的结构对立体定向性也有很大影响。用 MAO 在 50-80°C 下激活的 Hf 和 Zr 的双叔丁基苯基取代配合物，生成高分子量聚丙烯（M(n)=130,000-360,000g/mol），具有高的等规度[mmmm]＞97%和高达 165°C 的熔点。