Transition metal complex, process for producing the same, and use

A transition metal complex of the formula (1):

• wherein A represents an atom of Group 16 of the periodic table;
• B1 represents an atom of Group 14 of the periodic table;
• M1 represents a transition metal atom of Group 4 of the periodic table;
• Cp1 represents a group having a cyclopentadiene anion backbone;
• R1, R2, R3, R4, R5 and R6 represent independently of one another a hydrogen atom, a halogen atom, a C1-C20 alkyl group optionally substituted with a halogen atom, a C7-C20 aralkyl group optionally substituted with a halogen atom, a C6-C20 aryl group optionally substituted with a halogen atom, a C1-C20 hydrocarbon-substituted silyl group in which the hydrocarbon is optionally substituted with a halogen atom, a C1-C20 alkoxy group optionally substituted with a halogen atom, a C7-C20 aralkyloxy group optionally substituted with a halogen atom, a C6-C20 aryloxy group optionally substituted with a halogen atom, or a C2-C20 hydrocarbon-disubstituted amino group;
• R7, R8, R9, R10, R11 , and R12 represent independently of one another a hydrogen atom, a C1-C20 alkyl group optionally substituted with a halogen atom, a C7-C20 aralkyl group optionally substituted with a halogen atom, or a C6-C20 aryl group optionally substituted with a halogen atom,
• with the proviso that adjacent groups among R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11 and R12 may be optionally bonded to each other to form a ring;
• and
• that a 1,3-diene consisting of R7, R8, R9, R10, R11, R12 and 4 carbon atoms coordinates on M1 without any limitation of its coordination form, and the 1,3-diene may be of either a cis or trans form, or a mixed form thereof, and the double bonds may be delocalized.