A novel 2,6-bis(imino)pyridyl iron complex, [2,6-(2-F-4-CH3C6H3N=CCH3)(2)C5H3N]FeCl2.H2O (3) has been synthesized by the reaction of the corresponding bis(imino)pyridyl ligand with FeCl2.4H(2)O in tetrahydrofuran (THF). The activity of complex 3 reaches to 10(7) g/mol Fe h in ethylene oligomerization, and the products are mostly (>90%) 1-butene, 1-hexene and 1-octene. As reaction temperature increases, the activities decrease rapidly and the product distributions shift to the low-molecular-weight part. The product distributions are almost unchanged when the Al/Fe molar ratio increases from 420 to 2500, but the catalytic activities increase rapidly at first and then decrease. Other three complexes (2,6-(2-X-4-Y-6-ZC(6)H(3)N=CCH3)(2)C5H3N}FeCl2.nH(2)O (X = CH3, Y = CH3, Z = H, n = 0 (1), X = F, Y = H, Z = F, it = 1 (2)) and {Fe[2,6-(2-FC6H3N=CCH3)(2)C5H3N}(2)](2), [FeCl4](2)(-).H2O (4) have been also synthesized for comparison and used for ethylene oligomerization. The ortho and para substituents on aniline have performed effects on oligomerization activities and distributions of oligomers for 2,6-bis(imino)pyridyl iron complexes. (C) 2004 Elsevier B.V. All rights reserved.