An oxo-nitrogenated vanadium complex having the general formula (I): in which: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7, mutually identical or different, represent a hydrogen atom; or are selected from optionally halogenated, linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; X.sub.1 and X.sub.2, mutually identical or different, 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, preferably C.sub.1-C.sub.15, alkyl groups, OCOR.sub.8 groups or OR.sub.8 groups in which R.sub.8 is selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups; Y is selected from ethers such as, for example, diethyl ether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1. Said oxo-nitrogenated vanadium complex having the general formula (I) may advantageously be used in a catalytic system for (co)polymerizing conjugated dienes.

An oxo-nitrogenated vanadium complex having the general formula (I): in which: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7, mutually identical or different, represent a hydrogen atom; or are selected from optionally halogenated, linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; X.sub.1 and X.sub.2, mutually identical or different, 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, preferably C.sub.1-C.sub.15, alkyl groups, OCOR.sub.8 groups or OR.sub.8 groups in which R.sub.8 is selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups; Y is selected from ethers such as, for example, diethyl ether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1. Said oxo-nitrogenated vanadium complex having the general formula (I) may advantageously be used in a catalytic system for (co)polymerizing conjugated dienes.

Provided is a polymerization catalyst including a metal complex obtained by mixing at least one ketimine derivative selected from the group consisting of a -ketimine compound and a tautomer thereof with a compound having at least one metal selected from among Group 4 and 5 transitional metals, an organoaluminum compound, and a halogen compound.

Provided is a polymerization catalyst including a metal complex obtained by mixing at least one ketimine derivative selected from the group consisting of a -ketimine compound and a tautomer thereof with a compound having at least one metal selected from among Group 4 and 5 transitional metals, an organoaluminum compound, and a halogen compound.

The present invention provides a spherical supported transition metal catalyst. The catalyst carrier is a spherical titanium/zirconium hydrophosphate compound, the primary catalyst is a transition metal compound, the co-catalyst is methylaluminoxane; the spherical titanium/zirconium hydrophosphate compound comprises one or several combinations of titanium hydrophosphate, modified titanium hydrophosphate and zirconium hydrophosphate. The present invention also provides a preparation method of said spherical supported transition metal catalyst and a use thereof in olefin polymerization, as well as the spherical titanium/zirconium hydrophosphate compound and its preparation method. The spherical, supported transition metal catalyst in the present invention has a high catalytic activity, and the polymer particles obtained have good morphology.

The present invention provides a spherical supported transition metal catalyst. The catalyst carrier is a spherical titanium/zirconium hydrophosphate compound, the primary catalyst is a transition metal compound, the co-catalyst is methylaluminoxane; the spherical titanium/zirconium hydrophosphate compound comprises one or several combinations of titanium hydrophosphate, modified titanium hydrophosphate and zirconium hydrophosphate. The present invention also provides a preparation method of said spherical supported transition metal catalyst and a use thereof in olefin polymerization, as well as the spherical titanium/zirconium hydrophosphate compound and its preparation method. The spherical, supported transition metal catalyst in the present invention has a high catalytic activity, and the polymer particles obtained have good morphology.