Patent ID: 8273678

Claim:
A polymerization catalyst comprising the reaction product of A.) a ligand of the formula I, wherein R 1 , R 2 , R 3 , and R 4 in each occurrence independently are the same or different hydrocarbyl substituents of 1 to 20 carbon atoms, hydrogen, halogen, or alkoxy groups of 1 to 8 carbon atoms; X in each occurrence independently is CR 6 with R 6 being hydrogen or an alkyl group of 1 to 8 carbon atoms; and R 5 is an organic divalent group of 4 to 40 carbon atoms and optionally substituted with the proviso that the two nodes X are not bound to the same atom or to vicinal atoms in the group R 5 ; and B.) an aluminum compound of the formula AlR 7 R 8 R 9 , wherein R 7 , R 8 and R 9 each independently is a C 1 to C 12 hydrocarbyl group, hydrogen, halogen, or an alkoxy group of 1 to 20 carbon atoms; and C.) a Lewis base selected from the group consisting of amines, phosphines, amides, nitriles, isonitriles, and alcohols.