A series of 15 iron complexes with omega-alkenyl functionalized bis(arylimino)pyri,dine ligands-was synthesized and characterized. After activation with methylalumoxane (MAO), these catalysts oligomerize or polymerize ethylene to give highly linear products. Their potential for self-immobilization during the polymerization process was investigated. The product composition and the molecular weights of the polyethylenes were analyzed and compared with the values resulting. from analogously alkyls substituted bis(arylimino)pyridine iron complexes. (C) 2007 Elsevier B.V. All rights reserved.