Synthesis and characterization of tridentate [O^-N(H)X] titanium complexes and their applications in olefin polymerization

A series of [O^-N(H)X]TiCl₃ complexes derived from (arylamino)methylene phenol are prepared. The molecular structures of the complexes are characterized by ¹H NMR, ¹³C NMR, and X-ray analysis. Upon activation with modified methylaluminoxane (MMAO), the titanium complexes display high thermal stability and single-site like ethylene (co)polymerization behavior at the temperatures of up to 150 °C. 1-Octene and 1-octadencene prove suitable to be incorporated into polyethylene backbone at 110 °C and the highest activity of 1.89 × 10⁶ g/mol(Ti)·h·atm can be achieved. The pendant group X has great influence on the catalytic behaviors of the complexes, and PPh₂ proves to be the optimal group.