Novel titanium (IV) complexes with 1,2-diolate ligands: Synthesis, structure and catalytic activities in ultra-high molecular weight polyethylene production

A series of titanium (IV) complexes 3a-f stabilized by 1,2-diolate ligands 2 a-e have been synthesized. Structures of complexes 3d and 3e have been determined by X-ray diffraction. Titanium atoms in these complexes have a distorted square-pyramidal environment. All resulting complexes are highly active in ethylene polymerization in the presence of {3Et2AlCl + MgBu2} or {1.5Et3Al2Cl3 + MgBu2} binary co-catalysts. In the latter case, higher molecular weights of UHMWPE samples (up to 7.7 106) are achieved. Obtained polymers are suitable for the modern processing methods – the solvent-free solid state formation of super high-strength (over 2.0 – 2.8 GPa) and high-modulus (up to 145 GPa) oriented film tapes. © 2018