Patent ID: 6946568

Claim:
A complex of the formula Ia or Ib, where the variables are defined as follows: Nu is selected from the group consisting O, S and N—R 7 ; M is selected from the group consisting Ti, Zr, Hf, V, Nb and Ta; y corresponds to the oxidation state of M minus 1; z corresponds to the oxidation state of M minus 2; X are identical or different and are selected from the group consisting of a halogen, C 1 -C 8 -alkyl, C 3 -C 12 -cycloalkyl, C 7 -C 13 -aralkyl, and a C 6 -C 14 -aryl, R 1 to R 7 are identical or different and are selected from the group consisting of a hydrogen, a substituted C 1 -C 18 -alkyl, an unsubstituted C 1 -C 18 alkyl, a substituted C 2 -C 18 alkenyl having from one to 4 isolated or conjugated double bonds, an unsubstituted C 2 -C 18 alkenyl having from one to 4 isolated or conjugated double bonds, a substituted C 3 -C 12 -cycloalkyl, an unsubstituted C 3 -C 12 -cycloalkyl, a C 7 -C 13 -aralkyl, an unsubstituted C 6 -C 14 -aryl, a substituted C 6 -C 14 -aryl, wherein the substituted C 6 -C 14 -aryl has one or more identical or different substituents selected from the group consisting of a substituted C 1 -C 18 -alkyl, an unsubstituted C 1 -C 18 -alkyl, a substituted C 1 -C 18 -alkenyl, an unsubstituted C 1 -C 18 - alkenyl, a C 3 -C 12 -cycloalkyl, a C 7 -C 13 -aralkyl, a C 6 -C 14 -aryl, a halogen, a substituted C 1 -C 6 -alkoxy, an unsubstituted C 1 -C 6 -alkoxy, a C 6 -C 14 -aryloxy, a SiR 8 R 9 R 10 , and O—SiR 8 R 9 R 10 ; an unsubstituted five-membered nitrogen-containing heteroaryl radical, a substituted five-membered nitrogen-containing heteroaryl radical, an unsubstituted six-membered nitrogen-containing heteroaryl radical, and a substituted six-membered nitrogen-containing heteroaryl radical; wherein one or more substituents are identical or different and are selected from the group consisting of a substituted C 1 -C 18 -alkyl, an unsubstituted C 1 -C 18 -alkyl, a substituted C 2 -C 18 -alkenyl, an unsubstituted C 2 -C 18 -alkenyl, a C 3 -C 12 -cycloalkyl, a C 7 -C 13 -aralkyl, a C 6 -C 14 -aryl, a halogen, a C 1 -C 6 -alkoxy, a C 6 -C 14 -aryloxy, a SiR 8 R 9 R 10 , or O—SiR 8 R 9 R 10 ; where adjacent radicals R 1 to R 5 may be joined to one another or to R 7 to form a 5-membered to 12-membered non-aromatic ring and adjacent radicals R 1 and R 6 may be joined to one another to form a 5-membered to 12-membered ring, which 5-membered to 12-membered rings may in turn bear substituents selected from the group consisting of a substituted C 1 -C 8 -alkyl, an unsubstituted C 1 -C 8 -alkyl, a substituted C 2 -C 8 -alkenyl, an unsubstituted C 2 -C 8 -alkenyl and having from one to 4 isolated or conjugated double bonds, a substituted C 3 -C 12 -cycloalkyl, an unsubstituted C 3 -C 12 -cycloalkyl, a C 7 -C 13 -aralkyl, and a C 6 -C 14 -aryl; R 8 to R 10 are identical or different and are selected from the group consisting of a hydrogen, a C 1 -C 8 -alkyl, a C 3 -C 12 -cycloalkyl, a C 7 -C 13 -aralkyl, and a C 6 -C 14 -aryl.