Abstract: New polycyclic cyclopentadiene compounds having the formula (II) wherein the various substituents and symbols R1, R2, R3, R4, R5, R6, R7, Z1 and Z2 and “n” have the meaning specified in the description. These compounds can form metallocene complexes with transition metals, which have shown unusual properties in the (co)polymerization of ethylene and alpha-olefins in general.

Abstract: New polycyclic cyclopentadiene compounds having the formula (II) wherein the various substituents and symbols R1, R2, R3, R4, R5, R6, R7, Z1 and Z2 and “n” have the meaning specified in the description. These compounds can form metallocene complexes with transition metals, which have shown unusual properties in the (co)polymerization of ethylene and alpha-olefins in general.

Abstract: New polycyclic cyclopentadiene compounds having the formula (II) wherein the various substituents and symbols R1, R2, R3, R4, R5, R6, R7, Z1 and Z2 and “n” have the meaning specified in the description.

Abstract: New polycyclic cyclopentadiene compounds having the formula (II) wherein the various substituents and symbols R1, R2, R3, R4, R5, R6, R7, Z1 and Z2 and “n” have the meaning specified in the description. These compounds can form metallocene complexes with transition metals, which have shown unusual properties in the (co)polymerization of ethylene and alpha-olefins in general.

Abstract: A catalytic system with an increased activity for the (co)polymerization of alpha-olefins comprises a catalyst of the metallocene type, which is capable of polymerizing olefins without aluminoxane, and a weak coordinating compound, which, when used in a polymerization process, enables a higher productivity than an analogous process carried out with the metallocene type catalyst per se.

Abstract: A solid catalyst component for the polymerization and copolymerization of ethylene and alpha- olefins, containing a metallocene supported on an inorganic solid carrier constituted by a porous silicon oxide, the supported metallocene having the formula (I): ##STR1## wherein M is a group of metal, R' and R" are dialkylamide groups, R'" has the same definition as R' or is a cyclopentadienyl consisting ligand, and A is an anion containing an .eta..sup.5 -cyclopentadienyl ring coordinated to metal M, and wherein a carbon atom of the .eta..sup.5 -cyclopentadienyl ring of anion A is covalently bonded to the surface of the porous inorganic solid carrier.

Abstract: A supported metallocene complex of a metal M selected from Ti, Zr or Hf, is prepared by a process comprising, in a first step, the reaction of an inorganic carrier containing hydroxyl groups with a compound (II) containing a cyclopentadienyl group and at least one alkoxysilane group reactive with said hydroxyl groups so as to chemically bind said cyclopentadienyl group to said carrier; and in a second step the reaction with a complex of said metal M capable of reacting with said supported cyclopentadienyl group without carrying out any intermediate metallation of the latter. This process is simple and convenient, and enables high concentrations of metal stably bound to the carrier, to be reached. The complex thus obtained can be used as solid component of a catalyst active in the polymerization of .alpha.-olefins, in the presence of a suitable co-catalyst, preferably consisting of an organo-oxygenated derivative of aluminum.