Abstract: A process is described for the purification of lanthanide carboxylates which comprises a step in which the hydrocarbon solution deriving from the synthesis of lanthanide carboxylate, containing said carboxylate and impurities of the corresponding carboxylic acid and/or water, is treated with an aqueous solution of a base in order to obtain a pH of the aqueous phase ranging from 9.0 to 12.2 and/or a step in which the hydrocarbon solution containing lanthanide carboxylate is treated with a solid selected from Na2SO4, MgSO4, Mg(ClO4)2, molecular sieves 3 ?, molecular sieves 4 ?, molecular sieves 5 ? and molecular sieves 13 X. Analytical methods are also described, which allow the purity of the lanthanide carboxylates to be non-destructively measured.

Abstract: A process is described for the purification of lanthanide carboxylates which comprises a step in which the hydrocarbon solution deriving from the synthesis of lanthanide carboxylate, containing said carboxylate and impurities of the corresponding carboxylic acid and/or water, is treated with an aqueous solution of a base in order to obtain a pH of the aqueous phase ranging from 9.0 to 12.2 and/or a step in which the hydrocarbon solution containing lanthanide carboxylate is treated with a solid selected from Na2SO4, MgSO4, Mg(ClO4)2, molecular sieves 3 ?, molecular sieves 4 ?, molecular sieves 5 ? and molecular sieves 13 X. Analytical methods are also described, which allow the purity of the lanthanide carboxylates to be non-destructively measured.

Abstract: A process is described for the preparation of ethylene copolymers having a wide molecular weight distribution, characterized in that it is carried out in the presence of meso- and rac-stereoisomeric mixtures of metallocene compounds having general formula (I), wherein A? and A?, the same or different, are a radical of the ??5-tetrahydroindenyl type (Ia)

Abstract: A process is described for the preparation of ethylene copolymers having a wide molecular weight distribution, characterized in that it is carried out in the presence of meso- and rac-stereoisomeric mixtures of metallocene compounds having general formula (I), wherein A? and A?, the same or different, are a radical of the ??5L-tetrahydroindenyl type (Ia).

Abstract: The present invention relates to metallocene compounds consisting of indenyl-cyclopentadienyl groups non-symmetrically joined by a bivalent radical. Said compounds can be conveniently used as components of catalysts for the polymerization of olefins.

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: A catalytic composition for the selective oligomerization of ethylene and a process for preparing light linear (?-olefins, especially 1-hexene and 1-octene, starting from ethylene, using this composition, said composition comprising the following components: (A) a compound of a transition metal M of Group 4 of the periodic table; (B) an organic compound containing the sulfonic group (>SO2) bonded to two carbon atoms; (C) a hydrocarbyl organometallic compound of a metal M? selected from elements of Groups 1, 2, 12, 13 or 14 of the periodic table; components (A), (B) and (C) being in such a quantity that the atomic ratios respectively of the metal M in (A), of the sulfur S in the sulfonic group of (B) and of the metal M? in (C), respect the following proportions: S/M=(from 0 to 20)/1 and M?/M=(from 2 to 2000)/1, on the condition that when the compound of the metal M in component (A) is not a sulfonic complex of M, the S/M ratio is greater than 0.5, preferably greater than 1.

Abstract: A process is described for the preparation of elastomeric EP(D)M copolymers and terpolymers, characterized in that it is carried out in the presence of metallocene compounds of general formula (I) having a racemic stereoisomerism

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: A process is described for the preparation of elastomeric EP(D)M copolymers and terpolymers, characterized in that it is carried out in the presence of metallocene compounds of general formula (I) having a racemic stereoisomerism.

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 “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 &agr;-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 &eegr;5-cyclopentadienyl ring coordinated to M; R′ or R″ each independently represents a group of an anionic nature &sgr;-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.

Abstract: 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

Abstract: 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 &agr;-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 &eegr;5-cyclopentadienyl ring coordinated to M; R′ 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 A′ and to the —CH2— methylene group by means of carbon atoms.

Abstract: Bridged cyclopentadienyl derivatives having general formula (I)A--X--B (I)wherein:1) A is a monofunctional hydrocarbyl radical having general formula (II) ##STR1## 2) --X-- is the bridge between A and B and consists of a bifunctional radical selected from an alkylene group, a silanylene group, an alkyl substituted silaalkylene group, a siloxasilanylene group;3) B is a monofunctional hydrocarbyl radical selected from:e) any of the A radicals defined above,f) a cyclopentadienyl radical.

Abstract: Process for preparing elastomeric copolymers of ethylene-propylene (EPM) type and elastomeric terpolymers of ethylene-propylene-diene (EPDM) type with a propylene content comprised within the range of from 15 to 75%, carried out in the presence of metallocenes of formula (I) ##STR1##

Abstract: Catalytic component for the copolymerization of ethylene with alpha-olefins having general formula (I): ##STR1## wherein: A is a cyclopentadienyl derivative having general formula (II) ##STR2## B is selected from: 1) any of the cyclopentadienyl derivatives A defined above2) a monofunctional cyclopentadienyl radical (F) selected from cyclopentadienyl, indenyl, fluorenyl and the relative alkyl, aryl, trialkylsilyl substituted derivatives;Q, a bridge between A and B, is a bifunctional radical.

Abstract: A description follows of catalysts of the metallocene type which can be used in the (co)polymerization of alpha-olefins, particularly in the preparation of elastomeric copolymers of ethylene.

Abstract: Cyclopentadienyl derivatives are described having general formula (I) ##STR1## where R, R.sub.1, R.sub.2, R.sub.4, equivalent to or different from one another, are selected from: --H, alkyl radicals having a number of carbon atoms from 1 to 5, cycloalkyl radicals having a number of carbon atoms from 5 to 8, aryl and alkylaryl radicals having a number of carbon atoms from 6 to 8, aralkyl radicals having a number of carbon atoms from 7 to 9; n is an integer from 2 to 18; with the proviso that the number of R different from H does not exceed 2; with the exclusion of the compound having n=3, R.dbd.R.sub.1 .dbd.R.sub.2 .dbd.R.sub.4 .dbd.H. The invention a-so describes the process for the preparation of the above-mentioned cyclopentadienyl derivatives.