Zirconium and hafnium complexes based on 2-aryl-8-arylaminoquinoline ligands: synthesis, molecular structure, and catalytic performance in ethylene copolymerization
作者:Ilya E. Nifant'ev、Pavel V. Ivchenko、Vladimir V. Bagrov、Sandor M. Nagy、Linda N. Winslow、Jean A. Merrick-Mack、Shahram Mihan、Andrei V. Churakov
DOI:10.1039/c2dt31856c
日期:——
A general and efficient approach toward new zirconium and hafnium complexes based on 2-aryl-8-arylaminoquinoline ligands was developed. These precursors, when activated with MAO/borate cocatalyst and supported on silica, result in active olefin polymerization catalysts. The ethylene copolymers produced under industrially relevant conditions show very high molecular weights and unique microstructures defined by the multisite nature of the catalyst. A site-diversification mechanism is proposed to explain the presence of at least five individual sites, as deduced from 3D-TREF analysis of ethylene–butene copolymers.
基于2-芳基-8-芳胺基喹啉配体的新型锆和铪配合物的一般性高效合成方法得以开发。这些前体物质在MAO/硼酸盐共催化剂活化并负载于硅胶上后,转化为活性烯烃聚合催化剂。在工业相关条件下制备的乙烯共聚物展现出极高的分子量和由催化剂多活性位点特性所定义的独特微观结构。针对乙烯-丁烯共聚物的三维TREF分析所推断出的至少五个独立位点的存在,研究提出了一个位点多样化机制以作解释。