Catalytic composition for the (co)polymerization of ethylene and other
.alpha.-olefins, including a metallocene complex of a metal M of group 4
of the periodic table or the product obtainable from the same combined
with a suitable activator, wherein said metallocene complex includes at
least one cyclopentadienyl group and at least one unsaturated hydrocarbyl
organic group bonded to the metal M, having the following formula (I):
-(A.sub.x D.sub.y U.sub.z)R.sup.I (I)
wherein:
A represents any monomeric unit deriving from a vinylaromatic group
polymerizable by means of anionic polymerization, having from 6 to 20
carbon atoms;
D represents any monomeric unit deriving from a conjugated diolefin
polymerizable by means of anionic polymerization, having from 4 to 20
carbon atoms;
U represents any generic optional monomeric unit deriving from an
unsaturated compound co-polymerizable with any of the above conjugated
diolefins D or vinylaromatic compounds A;
R.sup.I represents hydrogen or a hydrocarbyl group having from 1 to 20
carbon atoms,
each index "x" and "y" can be independently zero or an integer, provided
the sum (x+y) is equal to or higher than 2, preferably between 2 and 50,
more preferably between 2 and 25;
"z" can be zero or an integer ranging from 1 to 20.
