Patent ID: 6908974

Claim:
A catalyst composition for preparing linear isotactic polymers, said catalyst composition containing a metal complex of general Formula I wherein R 1 and R 2 together and R 3 and R 4 together are each integrated into a C 5 to C 7 cycloalkyl or aryl rings, and R 6 and R 7 are linear or branched C 1 to C 10 alkyl, C 5 to C 7 cycloalkyl which, in its turn, can carry one or several C 1 to C 6 alkyl residues as substituent, C 6 to C 18 aryl or arylalkyl or alkylaryl, and can be partially or simultaneously integrated into C 5 to C 7 cycloalkyl or aryl rings fused thereto; E —CH 2 —, —CH 2 CH 2 —, —CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 CH 2 —, —CR 9 R 10 —, —SiH 2 —, —SiR 9 R 10 —, —GeH 2 —, or —GeR 9 R 10 —, wherein R 9 and R 10 can be a C 1 to C 8 alkyl, a C 4 to C 7 cycloalkyl or C 6 to C 7 aryl, in which case R 9 and R 10 can be joined together to form a ring structure; R 11 C 1 to C 8 alkyl, aryl, C 1 to C 8 oxyalkyl, or C 1 to C 8 trialkylsiloxy; M titanium, zirconium, hafnium, vanadium, niobium, or tantalum; and X halogen, C 1 to C 8 alkyl, aryl, or benzyl; and an activator.