二甲基二茂锆化合物(1,2-Ph_2-4-MeCp)_2ZrMe_2的合成及催化乙烯聚合反应研究

Synthesis of Complex(1,2-Ph_2-4-MeCp)_2ZrMe_2 and Catalysis for Ethylene Polymerization

在惰性气氛下,用2 mol甲基锂处理二(1,2-二苯基-4-甲基环戊二烯基)二氯化锆,合成了大立体位阻的二甲基二茂锆化合物[(1,2-Ph2-4-M eCp)2ZrM e2].经元素分析、核磁共振氢谱、碳谱和X射线晶体衍射分析,确定了该化合物的结构.经A l(iBu)3/Ph3C+B(C6F5)4-活化,该化合物催化乙烯聚合反应显示出较高的催化活性,生成高分子量及高熔点聚乙烯.该体系的特点是在较低的n(A l)/n(Zr)比下即可有效地催化乙烯聚合.

A new dialkylzirconocene type of complex, （1,2-ph2-4-MeCp）2ZrMe2 （2）, was synthesized by reaction of （1,2-Ph2-4-MeCp）2ZrCl2 （1） and with 2 equivalent of methyl lithium at -78℃. Complex 2 was charcterized by elemental analysis, ^1H NMR and ^13C NMR. The structure of complex 2 was determined by single crystal X-ray structural analysis. Upon activation with Al（^iBu）3/Ph3C^＋ B（C6F5）f , complex 2 showed a high catalytic activity for the ethylene polymerization reaction at lower n（Al）/n（Zr） ratios and high molecular weight polyethylene samples with high melting transition temperatures were produced. The polyethylene samples were characterized by molecular weight determination, DSC and XRD analysis.