2‐Benzoxazolyl‐6‐[1‐(arylimino)ethyl]pyridyliron(II) Chlorides as Ethylene Oligomerization Catalysts

A series of iron(II) dichloride complexes (Fe1–Fe7) ligated by 2‐(2‐benzoxazolyl)‐6‐[1‐(arylimino)ethyl]pyridines was synthesized and characterized [aryl = 2,6‐R12C6H3; R1 = Me (1), Et (2), iPr (3), Cl (4), Br (5); 2,6‐Me2C6H2‐4‐R2, R2 = Me (6), Br (7)]. The molecular structures of Fe1, Fe3, and Fe5 were determined by the single‐crystal X‐ray diffraction. Complexes Fe1 and Fe3 both display distorted trigonal‐bipyramidal geometries, whereas complex Fe5 is a distorted square pyramid. Upon activation with modified methylaluminoxane, all iron complexes showed moderate to good activities [up to ca. 106 g(product) × (mol Fe)–1 h–1 bar–1] for the oligomerization and polymerization of ethylene, with high selectivity for vinyl‐terminated oligomers or polyethylene waxes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)