A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other a-olefins is represented by means of the following formula (II):
1
wherein: M represents a metal selected from titanium, zirconium or hafnium;
A′ and A″ each independently represent an anion containing an &eegr;
5
-cyclopentadienyl ring coordinated to M;
or R″ each independently represents a group of an anionic nature a-bound to the metal M;
B represents an unsaturated bivalent organic residue having from 1 to 30 carbon atoms bound, respectively, to the ring of group and to the -CH
2
- methylene group by means unsaturated carbon atoms.
This complex, combined with a suitable cocata forms a catalyst with a high activity in the poization of olefins, producing polymers with molecular weight, especially in the case of the merization of ethylene with a second &agr;-olefir.
下面是翻译结果:
一种“桥式”双
环戊二烯基配合物,可优选用于形成催化活性的(共)聚
乙烯和其他α-烯烃的催化系统,其由以下公式(II)表示:1
其中:M代表从
钛、
锆或
铪中选择的
金属;
A′和A″各自独立地表示含有&egr;5-
环戊二烯基环配位到M的阴离子;
或R″各自独立地表示与
金属M相结合的带有阴离子性质的基团;
B代表一个不饱和的双价有机残基,其分别通过不饱和碳原子结合到环和-
CH2-亚甲基团。
该配合物与合适的协同剂结合形成催化剂,在烯烃的聚合中具有高活性,特别是在
乙烯与第二个&agr;-烯烃的聚合中,产生分子量高的聚合物。