Several non-metallocene-type titanium(IV) complexes containing phenoxy-phosphine or thiophenoxy-phosphine ligands of type, (2-R-1-4-R-2-6-PPh2-C6H2X)(2)TiCl2 (2a: X O, R-1 = R-2 = t-Bu; 2b X = O, R-1 = R-2 = cumyl, 2c X = S, R-1 = SiMe3, R-2 - H) have been synthesized by treating TiCl4 with the corresponding ligands 2-R-1-4-R-2-6-PPh2-C6H2XH in the presence of n-BuLi The complexes 2a-c were investigated as the catalysts for ethylene with 1-hexene and/or polar alkenes copolymerizations The catalytic activity and the comonomer incorporation were highly dependent upon catalyst and reaction conditions employed Among these complexes, 2a can not only promote ethylene/1-hexene living copolymerization at room temperature, but also can utilize ethylene with methyl 10-undecenoate copolymerization (C) 2010 Elsevier Ltd All rights reserved