Ethylene/hexene living copolymerization and ethylene/methyl 10-undecenoate copolymerization by titanium complexes bearing phenoxy-phosphine or thiophenoxy-phosphine ligands

Several non-metallocene-type titanium(IV) complexes containing phenoxy-phosphine or thiophenoxy-phosphine ligands of type, (2-R1-4-R2-6-PPh2-C6H2X)2TiCl2 (2a: X = O, R1 = R2 = t-Bu; 2b: X = O, R1 = R2 = cumyl; 2c: X = S, R1 = SiMe3, R2 = H) have been synthesized by treating TiCl4 with the corresponding ligands 2-R1-4-R2-6-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.