C2-bridged metallocene dichloride complexes of the types (C13H8-CH2CHR-C9H6-nR′n)ZrCl2 and (C13H8-CH2CHR-C13H8)MCl2 (n = 0, 1; R = H, alkenyl; R′ = alkenyl, benzyl; M = Zr, Hf) as self-immobilizing catalyst precursors for ethylene polymerization

A total of 15 C-2-bridged fluorenylidene indenylidene and bis(fluorenylidene) metal dichloride complexes (metal = Zr, Hf) and the corresponding ligand precursors have been prepared and characterized. omega-Alkenyl substituents with various chain lengths in the C-2-bridge or in position 3 of the indenylidene moiety have an impact on the polymerization activity of the catalysts and the molecular weights of the produced polyethylenes. These omega-alkenyl substituents cause 'self-immobilization' due to their incorporation into the backbone of a growing polymer chain providing heterogeneous catalyst systems. (C) 1999 Published by Elsevier Science S.A. All rights reserved.