Synthesis and catalytic properties for olefin polymerization of new vanadium complexes containing silsesquioxane ligands with different denticity

Synthesis and catalytic performance in ethylene and 1-octene polymerization of chlorotitanium(IV) silsesquioxane complexes. Effect of increasing ligand denticity and type of nonreactive organic substituents

Abstract The series of titanasilsesquioxanes that differ in a way of binding to the transition metal ( via one, two or three oxygen atoms) and type of nonreactive substituents bonded to inorganic oxygen-silicon cage ( i -Bu, Ph, c -C 6 H 11 ) were prepared by reacting of TiCl 4 with 1 eqv. of the silsesquioxane ligand. Upon treatment with an appropriate cocatalyst, all titanium precatalysts are active in ethylene and 1-octene polymerization and produce from low to high molecular weight polyethylenes and moderately ([ mmmm ] = 44–74%) isotactic poly(1-octene)s. The influence of polymerization parameters, type of cocatalyst and the silsesquioxane structure on the catalytic behavior of the tit…