A series of 2-benzimidazolyl-N-phenylquinoline-8-carboxamide half-titanocene chlorides, CpTiLCl (C1-C6 Cp = eta(5)-C(5)H(5); L = 2-(1H-benzo[d]imidazol-2-yl)-N-(2,6-R(1)-4-R(2)-phenyl)- quinoline-8-carboxamide derivatives; Cl: R(1) = i-Pr, R(2) = H; C2: R(1) Et, R(2) = H; C3: R(1) = Me, R(2) = H; C4: R(1) = Me, R(2) = Me; C5: R(1) = H, R(2) = H; C6: R(1) = F, R(2) = H), have been synthesized by the stoichiometric reaction of half-titanocene trichlorides with the corresponding potassium 2-benzimidazolyl-N-Phenylquinoline-8-carboxamide. All complexes are fully characterized by elemental and NMR analyses, as well as single-crystal X-ray diffraction for complexes C1, C2, and C6. In addition, the oxo-bridged dinuclear complex C7 was separated from the solution of C6 in These catalytic air. These complexes, C1-C6, activated with methylaluminoxane (MAO), exhibit high activities toward both ethylene polymerization land copolymerization of ethylene with alpha-olefins. According to the catalytic system of C1/MAO. both elevating the reaction temperature and increasing the ratio of MAO to titanium precursor enhance the productivities; however, the molecular weights of the resultant polymers obtained decrease against their higher activities. Moreover, copolymerizations of ethylene with either 1-hexene or 1-octene effectively produce copolymers with incorporated comonomers of 2.0-5.0% mol.