柄型金属有机化合物(V)——锗桥连茚基及取代茚基锆化合物的合成及催化烯烃聚合

锗桥连茚及取代茚配体相继与丁基锂及ＺｒＣｌ４作用,生成锗桥连茚基及取代茚基锆化合物Ｍｅ２Ｇｅ(２－Ｒ１－４－Ｒ２－Ｉｎｄ)２ＺｒＣｌ２Ｒ１＝Ｒ２＝Ｈ(１);Ｒ１＝Ｍｅ,Ｒ２＝Ｈ(２);Ｒ１＝Ｍｅ,Ｒ２＝Ｐｈ(３)]．化合物１－３均为内消旋和外消旋异构体的混合物,通过多次重结晶得到化合物１和２的纯外消旋异构体及化合物３的内消旋异构体．由元素分析和１Ｈ ＮＭＲ谱表征了化合物的分子结构．研究了在甲基铝氧烷(ＭＡＯ)的助催化下,化合物１－３对乙烯和丙烯聚合的催化性能．由锗桥连茚基化合物１－３得到的聚乙烯的分子量分布比一般茂金属催化剂略宽．内消旋和外消旋异构体的混合物(３)由于两个催化活性中心不等同而使得到的聚乙烯的分子量分布相当宽．外消旋异构体１和２催化丙烯聚合得到高等规聚丙烯．

Ansa-Metallocene Complexes(V)- Synthesis and Application in Olefin Polymerization ofGerma-bridged Indenyl and Substituted Indenyl Zirconium Complexes

Germa-bridged indenyl and substituted indenyl ligands react with n-butyl lithium and ZrCl4 togive Germa-bridged indenyl and substituted indenyl zirconium complexes Me,Ge (2-R1-4-R2-Ind)2 ZrCl2R1=R2=H(1); R1 =Me, R2 =H(2) ; R1 =Me, R2 =Ph(3) ]. Compounds 1-3 are mixture of rac andmeso isomers. After fractional crystallization pure rac-1, rac-2 and meso-3 were isolated. Compounds 1-3were characterized by 1H NMR and elemental analyses and used for the polymerization of ethylene andpropylene in the presence of methyl aluminoxane (MAO). The molecular weight distribution of thepolyethylene obtained with compounds 1-3 is slightly broader than that with general metallocenes. A-mong them, the molecular weight distribution of the polyethylene obtained with the mixture of rac-3 andmeso-3 is much broader due to the two unequal catalytic active centers in the system. Compounds rac-1 andrac-2 catalyzed propylene polymerization to give isotactic polypropylene.