A series of titanium complexes Cp*TiCl((OCH(R)CH2)(2)NAr) (Cp* = C5Me5, R = H, Ar = Phenyl (2a); R = H, Ar = 2,6-dimethylphenyl (2b); R = Me, Ar = Phenyl (2c)) was prepared by the reaction of corresponding N,N-diethoxylaniline derivatives, with Cp*TiCl, in the presence of excessive triethylamine. All the titanium complexes display higher catalytic activities towards the syndiospecific polymerization of styrene in the presence of modified methylaluminoxane (MMAO) as a cocatalyst, and produce higher molecular weight polystyrenes with higher syndiotacticity and melting temperature than their mother complex Cp*TiCl3, The catalyst activities and polymer yields as well as polymer properties are considerably affected by the steric and electronic effect of the tridentate ligands. (c) 2005 Wiley Periodicals, Inc.