| 摘要 |
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 alpha-olefins is represented by means of the following formula (II):wherein: M represents a metal selected from titanium, zirconium or hafnium; A' and A'' each independently represent an anion containing an eta5-cyclopentadienyl ring coordinated to M; R' or R'' each independently represents a group of an anionic nature sigma-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 A' and to the -CH2-methylene group by means of carbon atoms. This complex, combined with a suitable cocatalyst, forms a catalyst with a high activity in the polymerization of olefins, producing polymers with a high molecular weight, especially in the case of the copolymerization of ethylene with a second alpha-olefin.
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