Patent ID: 6894179

Claim:
A compound represented by the formula: wherein: M 1 is selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten; R 1 and R 2 are identical or different, and are one of a hydrogen atom, a C 1 -C 10 alkyl group, a C 1 -C 10 alkoxy group, a C 6 -C 10 aryl group, a C 6 -C 10 aryloxy group, a C 2 -C 40 alkenyl group, a C 7 -C 40 arylalkyl group, a C 7 -C 40 alkylaryl group, a C 8 -C 40 arylalkenyl group, an OH group or a halogen atom, or are a conjugated diene which is optionally substituted with one or more hydrocarbyl, tri(hydrocarbyl)silyl groups or tri(hydrocarbyl)silylhydrocarbyl groups, said diene having up to 30 atoms not counting hydrogen; R 3 are identical or different and are each a hydrogen atom, a halogen atom, a C 1 -C 10 alkyl group which may be halogenated, a C 6 -C 10 aryl group which may be halogenated, a C 2 -C 10 alkenyl group, a C 7 -C 40 arylalkyl group, a C 7 -C 40 alkylaryl group, a C 8 -C 40 arylalkenyl group, a —NR′ 2 , —SR′, —OR′, —OSiR′ 3 or —PR′ 2 radical, wherein: R′ is one of a halogen atom, a C 1 -C 10 alkyl group, or a C 6 -C 10 aryl group; R 4 to R 7 are identical or different and are hydrogen, as defined for R 3 or two or more adjacent radicals R 5 to R 7 together with the atoms connecting them form one or more rings; R 13 is represented by the formula: wherein: R 17 to R 24 are one of a hydrogen atom, a C 1 -C 10 alkyl group, a C 1 -C 10 alkoxy group, a C 6 -C 10 aryl group, a C 6 -C 10 aryloxy group, a C 2 -C 40 alkenyl group, a C 7 -C 40 arylalkyl group, a C 7 -C 40 alkylaryl group, a C 8 -C 40 arylalkenyl group, an OH group, or a halogen atom, or two or more adjacent radicals R 17 to R 24 , including R 20 and R 21 , together with the atoms connecting them form one or more rings; M 2 is carbon, silicon, germanium or tin; and R 8 , R 9 , R 10 , R 11 and R 12 are identical or different and have the meanings stated for R 4 to R 7 .