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

• Titanasilsesquioxanes with different structures as polymerization precatalysts.
• Homopolymerization of ethylene and 1-octene.
• Ethylene/1-octene copolymerization.
• Complex structure-cocatalyst type-property-relationships.

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-C6H11) were prepared by reacting of TiCl4 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 title titanium silsesquioxane complexes have been investigated.

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