Polymerization-active transition metal complexes having bulky ligand systems

A transition metal compound of the formula

• 4
• where the substituents and indices have the following meanings:
• R1, R3 are hydrogen, C1-C20-alkyl, C3-C10-cycloalkyl, C6-C16-aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl part and from 6 to 16 carbon atoms in the aryl part, Si(R6)3, N(R6)(R7), OR6 SR6 or R1 and R3 together with Ca, Cb and, if present, C′ form a five-, six- or seven-membered aliphatic or aromatic, substituted or unsubstituted carbocyclic or heterocyclic ring,
• R2, R4 are C4-C16-heteroaryl or C6-C16-aryl bearing C4-C16-heteroaryl or C6-C16-aryl substituents in the two vicinal positions relative to the linkage point to Na or Nb,
• R5 is hydrogen, C1-C10-alkyl, C6-C16-aryl or alkylaryl having from 1 to 10 carbon atoms in the alkyl part and from 6 to 16 carbon atoms in the aryl part,
• R6, R7 are C1-C10-alkyl, C6-C16-aryl or alkylaryl having from 1 to 10 carbon atoms in the alkyl part and from 6 to 16 carbon atoms in the aryl part,
• m is 0 or 1,
• M is a metal of group VIIIB of the Periodic Table of the Elements,
• T, Q are uncharged or monoanionic monodentate ligands or T and Q together form a diketoenolate unit or a C2— or C3-alkylene unit having a methyl ketone end group or a linear C1-C4-alkylester or nitrile end group,
• A is a noncoordinating or weakly coordinating anion,
• x, p are 0, 1, 2 or 3 and
• q, n are 1, 2 or 3.