Highly Thermally Stable Eight-Coordinate Dichloride Zirconium Complexes Supported by Tridentate [ONN] Ligands: Syntheses, Characterization, and Ethylene Polymerization Behavior
作者:Aike Li、Haiyan Ma、Jiling Huang
DOI:10.1021/om4009636
日期:2013.12.23
A series of novel eight-coordinate dichloride zirconium complexes with the general formula L2ZrCl2 supported by two tridentate [ONN] ligands have been synthesized by the reaction of ZrCl4·2THF with 2 equiv of the corresponding ligands (tridentate phenoxy-imine ligands (L1H–L4H) or tridentate phenoxy-amine ligands (L5H and L6H)). These complexes were characterized by NMR and elemental analyses. The molecular
一系列新颖的八坐标二氯化锆配合物与一般式L 2的ZrCl 2由两个三齿支撑[ONN]配体已通过的ZrCl的反应合成的4 ·2THF与2当量的相应的配体(三齿苯氧基-亚胺配体的(大号1 ħ -大号4 ħ)或三齿苯氧基-胺配体(大号5 ħ和大号6 ħ))。通过NMR和元素分析这些复合物进行了表征。代表锆的分子结构复合物C2和C6由两个三齿通过单晶X-射线衍射证实和显示,该金属中心是八配位[ONN]配体和在一个扭曲的平方反棱柱几何2和氯化物。当C1 - C6是由改性的甲基(MMAO)激活时,所得到的催化剂显示显着的热稳定性和朝向乙烯聚合的高活性。的配体的取代基,所述金属配位环境,以及反应条件有聚合产生深远的影响。随着聚合温度的催化活性持续增加,并且为1.04×10活性最高6克PE锆(Zr摩尔) -1 ħ -1是在实现Ò二甲苯在140℃下。观察到近5小时的催化寿命为C5 / MMAO催化剂体系在140℃。