Abstract: The invention relates to a metallocene complex according to formula (1) wherein M is a metal selected from lanthanides or transition metals from group 3, 4, 5 or 6 of the Periodic System of the Elements, Q is an anionic ligand to M, k is the number of Q groups and equals the valence of M minus 2, Z1, Z2, Z3 and Z4 are identical or different and can be chosen from the group consisting of hydrogen and a hydrocarbon radical with 1-20 carbon atoms, and adjacent substituents Z can form a ring system together with the carbon atoms of the Cp ring to which they are bound.

Abstract: A metallocene complex according to formula 1 wherein M is a metal selected from lanthanides or transition metals from group 3, 4, 5, or 6, Q is an anionic ligand to M, k is the number of Q groups and equals the valence of M minus 2, X is a cyclic bridging group that is bonded to a carbon atom of the cyclopentadienyl ligand and to nitrogen, Z1, and Z4 are hydrogen or a hydrocarbon radical with 1-20 carbon atoms; adjacent substituents Z2 and Z3 and are connected to form an indenyl or tetrahydroindenyl ring system and R is hydrogen or a hydrocarbon radical with 1-20 carbon atoms. Also described is a composition comprising the metallocene complex, a process for the preparation of the complex, and a process for the polymerization of olefin polymers in the presence of the metallocene complex.