The series of half-titanocene 2-(1-(arylimino)ethyl)quinolin-8-olate dichlorides, Cp 0 TiCl 2 L (Cp 0 = Z 5 -C 5 H 5 or Z 5 -C 5 Me 5 , L = 2-(1-(2,6-R 1 -4-R 2 -phenylimino)ethyl)quinolin-8-olate), was synthesized via the stoichiometric reaction of Cp 0 TiCl 3 with the corresponding potassium salt, viz. 2-(1-(2,6-R 1 -4-R 2 -phenylimino)ethyl)quinolin-8-olate. All compounds were characterized by elemental analysis, 1 H and 13 C NMR spectroscopy. The molecular structures of complexes C2 and C4 were determined by single-crystal X-ray diffraction. When activated with methylaluminoxane (MAO), all half-titanocene pre-catalysts exhibited high activities for ethylene polymerization and co-polymerization with a-olefins or norbornene.