Vanadium pyridine-imine complex having general formula (I), wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, optionally halogenated cycloalkyl groups optionally substituted, aryl groups optionally substituted; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, OCOR.sub.7 groups or OR.sub.7 groups wherein R.sub.7 is selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15; Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1. Said vanadium pyridine-imine complex having general formula (I) can be advantageously used in a catalytic system for the (co) polymerization of conjugated dienes. ##STR00001##

Vanadium pyridine-imine complex having general formula (I), wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, optionally halogenated cycloalkyl groups optionally substituted, aryl groups optionally substituted; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, OCOR.sub.7 groups or OR.sub.7 groups wherein R.sub.7 is selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15; Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1. Said vanadium pyridine-imine complex having general formula (I) can be advantageously used in a catalytic system for the (co) polymerization of conjugated dienes. ##STR00001##

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I): wherein: m is 0 or 1; Z represents a CR.sub.5R.sub.6 group wherein R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or a C.sub.1-C.sub.20 alkyl group, preferably C.sub.1-C.sub.15, linear or branched; or a bivalent aromatic group optionally substituted; R.sub.1 and R.sub.2 equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or R.sub.1 and R.sub.2, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; R.sub.3 and R.sub.4, equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or R.sub.2 and R.sub.4, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or R.sub.1 and R.sub.3, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.1, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, OCOR.sub.7 groups or OR.sub.7 gro

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I): wherein: m is 0 or 1; Z represents a CR.sub.5R.sub.6 group wherein R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or a C.sub.1-C.sub.20 alkyl group, preferably C.sub.1-C.sub.15, linear or branched; or a bivalent aromatic group optionally substituted; R.sub.1 and R.sub.2 equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or R.sub.1 and R.sub.2, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; R.sub.3 and R.sub.4, equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or R.sub.2 and R.sub.4, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or R.sub.1 and R.sub.3, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.1, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, OCOR.sub.7 groups or OR.sub.7 gro

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I): wherein: m is 0 or 1; Z represents a CR.sub.5R.sub.6 group wherein R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or a C.sub.1-C.sub.20 alkyl group, preferably C.sub.1-C.sub.15, linear or branched; or a bivalent aromatic group optionally substituted; R.sub.1 and R.sub.2 equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or R.sub.1 and R.sub.2, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; R.sub.3 and R.sub.4, equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or R.sub.2 and R.sub.4, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or R.sub.1 and R.sub.3, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.1, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, OCOR.sub.7 groups or OR.sub.7 gro

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I): wherein: m is 0 or 1; Z represents a CR.sub.5R.sub.6 group wherein R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or a C.sub.1-C.sub.20 alkyl group, preferably C.sub.1-C.sub.15, linear or branched; or a bivalent aromatic group optionally substituted; R.sub.1 and R.sub.2 equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or R.sub.1 and R.sub.2, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; R.sub.3 and R.sub.4, equal to or different from each other, represent a hydrogen atom; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or R.sub.2 and R.sub.4, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or R.sub.1 and R.sub.3, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.1, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, linear or branched, OCOR.sub.7 groups or OR.sub.7 gro

Vanadium pyridine-imine complex having general formula (I), wherein:R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, optionally halogenated cycloalkyl groups optionally substituted, aryl groups optionally substituted;X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, OCOR.sub.7 groups or OR.sub.7 groups wherein R.sub.7 is selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15;Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is etrahydrofuran (THF);n is 0 or 1. Said vanadium pyridine-imine complex having general formula (I) can be advantageously used in a catalytic system for the (co) polymerization of conjugated dienes.

##STR00001##

Vanadium pyridine-imine complex having general formula (I), wherein:R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6, equal to or different from each other, represent a hydrogen atom; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, optionally halogenated cycloalkyl groups optionally substituted, aryl groups optionally substituted;X.sub.1, X.sub.2 and X.sub.3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or are selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15, OCOR.sub.7 groups or OR.sub.7 groups wherein R.sub.7 is selected from linear or branched C.sub.1-C.sub.20 alkyl groups, preferably C.sub.1-C.sub.15;Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is etrahydrofuran (THF);n is 0 or 1. Said vanadium pyridine-imine complex having general formula (I) can be advantageously used in a catalytic system for the (co) polymerization of conjugated dienes.

##STR00001##