Effect of the Bridging Unit in Bis-( Benzoxazolyl ) Titanium , Zirconium and Vanadium Complexes on Catalytic Ethylene Polymerization Reactions

Abstract

A series of 32 complexes of 1,1-bis-(benzoxazolyl)methane, 1,2-bis-(benzoxazolyl) ethane, 1,2-bis-(benzoxazolyl)benzene and 2,6-bis-benzoxazolyl)pyridine compounds with Ti(IV) chloride, Zr(IV) chloride and V(III) chloride was synthesized and characterized. After activation with methylaluminoxane (MAO), these complexes proved as good ethylene polymerization catalysts. Surprisingly the activities of the corresponding catalysts depend considerably on the nature of the bridging unit of the ligand. Structure property relationship studies revealed that titanium complex 16 with a methylene bridge gave the best performance.

Ti (IV) Complexes of Some Heterocyclic Ligands Synthesis, Characterization and Ethylene Polymerization Activity

“…The vanadium complexes of bis(benzimidazole)amine tridentate ligands [N, N, N], were reported as active ethylene polymerization catalysts after activation with simple alkylaluminum compounds 31 2,6-Bis(2-benzimidazolyl)pyridine zirconium dichloride / MAO polymerizes methylacrylate 32 Recently, [33][34][35][36][37][38][39] we reported the ethylene polymerization activity of benzimidazole, benzothiazole, benzoxazole and 2-(benzimidazolyl) pyridine titanium zirconium and vanadium complexes. Herein we report on the effect of hetero atom on the activity of zirconium, complexes of bis (benzimidazole), benzothiazole, and benzoxazole), and their behaviour towards ethylene polymerization after activation with methylaluminoxane (MAO).…”