A series of N-(2-benzimidazolyquinolin-8-yl)benzamidate half-titanocene chlorides, Cp'TiLCl (C1-C8 Cp' = C5H5, MeC5H4, or C5Me5; L = N-(benzimidazolyquinolin-8-yl)benzamides)), was synthesized by the KCl elimination reaction of half-titanocene trichlorides with the correspondent potassium N-(2-benzimidazolyquinolin-8-yl)benzamide. These half-titanocene complexes were fully characterized by elemental and NMR analyses, and the molecular structures of complexes C2 and C8 were determined by the single-crystal X-ray diffraction. The high stability of the pentamethylcyclopentadienyl complex (C8) was evident by no decomposing nature of its solution in air for one week. The oxo-bridged dimeric complex (C9) was isolated from the solution of the corresponding cyclopentadienyl complex (C3) solution in air. Complexes C1-C8 exhibited good to high catalytic activities toward ethylene polymerization and ethylene/alpha-olefin copolymerization in the presence of methylaluminoxane (MAO) cocatalyst. In the typical catalytic system of C1/MAO, the polymerization productivities were enhanced with either elevating reaction temperature or increasing the ratio of MAO to titanium precursor. In general, it was observed that higher the catalytic activity of the catalytic system lower the molecular weight of polyethylene. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3154-3169, 2009