Synthesis and crystal structures of unbridged bis(4-R-1,2-diphenylcyclopentadienyl)zirconium dichlorides (R=phenyl, cyclohexyl), and catalysis for olefin polymerization
作者:Fan Zhang、Ying Mu、Jianhui Wang、Zhan Shi、Weiming Bu、Shirong Hu、Yuetao Zhang、Shouhua Feng
DOI:10.1016/s0277-5387(00)00484-8
日期:2000.9
e (1) or 4-cyclohexyl-1,2-diphenylcyclopentadiene (2), respectively. The single-crystal X-ray structure analysis reveals that both complexes crystallize in C2-symmetric conformation in solid state. When activated with methylaluminoxane (MAO), complexes 3 and 4 polymerize ethylene with moderate activities to produce ultra-high-molecular-weight polyethylenes with high melting transition temperatures
锆配合物承载空间庞大的三取代的环戊二烯基配位体,(η 5 -4-R-1,2--PH 2 ç 5 ħ 2)2的ZrCl 2 [R =苯基(3),环己基(4)],由合成ZrCl 4与分别为1,2,4-三苯基环戊二烯(1)或4-环己基-1,2-二苯基环戊二烯(2)的锂盐的反应。单晶X射线结构分析表明,两种配合物均以固态的C 2对称构型结晶。当用甲基铝氧烷(MAO)活化时,配合物3和4具有中等活性聚合乙烯以生产超高分子量聚乙烯具有高熔点转变温度在低的Al / Zr的比率。在环境条件下,3 -MAO和4 -MAO两种体系均表现出较高的丙烯低聚活性。用3 –MAO体系制得的聚丙烯的分子量低于用4 –MAO体系制得的聚丙烯的分子量。与4相比,配合物3在乙烯和丙烯聚合中均更具活性。