The iron-based catalyst 2,6-bis[1-(4-bromo-2,6-dimethylphenylimino)ethyl]-pyridineiron(II) chloride, 1, has been successfully synthesized and characterized. Its catalytic activity was evaluated for the polymerization of ethylene at different temperatures and Al/Fe ratios and compared with that of 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridineiron(II) chloride, 2. The results show that the catalytic activity of catalyst 1 is highly dependent on the amount of MAO used in the polymerization of ethylene and presents a maximum value at about 20degreesC. (C) 2003 Elsevier B.V. All rights reserved.