Novel heteroligated titanium complexes with fluorinated salicylaldiminato and β-enaminoketonato ligands: synthesis, characterization and catalytic behavior in vinyl addition polymerization of norbornene
作者:Ying-Yun Long、Wei-Ping Ye、Ping Tao、Yue-Sheng Li
DOI:10.1039/c0dt01225d
日期:——
The X-ray crystallographic analysis indicated these complexes adopted a distorted octahedral geometry around the titanium center. Upon activation with modified methylaluminoxane, complexes 3a–g exhibited moderate to good catalytic activity for norbornene (NB) vinyl addition polymerization, producing moderate molecular weight polynorbornenes under mild conditions. The introduction of electron-withdrawing
一系列通式为[3-Bu t -2-OC 6 H 3 CH N(C 6 F 5)] [PhN C(CF 3)CHC(R)的杂合的(水杨基亚氨基)(β-烯氨基酮基)钛配合物O] TiCl 2(3a:R Ph,3b:R C 6 H 4 Ph(p),3c:R C 6 H 4 Ph(o),3d:R = 1-萘基,3e:R = C 6 H 4 F 2(2,6),3f:R = C 6 H 4 Cl 2(2,5),3g:R C 6 F 4(2,3,5,6)OMe(4)。配合物3d,3f–g的结构通过单晶X射线衍射分析确定。X射线晶体学分析表明这些络合物在钛中心周围采用了扭曲的八面体几何形状。经修饰的甲基铝氧烷活化后,配合物3a–g表现出中等至良好的催化活性。降冰片烯(NB)乙烯基加成聚合反应,在温和条件下产生中等分子量的聚降冰片烯。吸电子基团的引入可以大大提高催化活性。重要的是,杂化的钛配合物与同等的对应