Titanium(IV) complexes with monocyclopentadienyl and phenoxy-alkoxo ligands: Synthesis, structures and catalytic properties for ethylene polymerization

摘要

Three monochlorotitanium complexes Cp'Ti(2,4-'Bu-2,-6-(CPh2O)C6H2,O)Cl [Cp'= eta(5)-C5H5 (2), eta(5)-C-5,(CH3)(5) (3), eta(5)-C5H2Ph2CH3 (4)] have been synthesized in high yields (> 90%) by the reaction of corresponding Cp'TiCl3 with the dilithium salt of ligand 2,4-'Bu-2-6(CPh2,OH)C6H,OH (1). When activated by [Ph3C](+)[B(C6F5)4](-) and (AlBu3)-Bu-i, complexes 2-4 exhibit reasonable catalytic activity for ethylene polymerization, producing polyethylenes with moderate molecular weights and melting points. Addition of excess water to complex 2 gave the oxo-bridged complex [Ti(eta(5)-C5H5)(2,4-'Bu-2,-6-(CPh2O)C6H2O)](2)O (5). Complexes 4 and 5 were characterized by single crystal X-ray diffraction. (c) 2007 Elsevier Ltd. All rights reserved.