Ligand Design of Post-Metallocene Catalysts to Obtain Block Copolymers

摘要

“Ligand design”, meaning the rational invention of a well-defined catalyst structure for a targeted application, is often associated with the metallocene and post-metallocene breakthroughs in stereoselective olefin polymerization. Such tailoring procedure might be applied in catalytic olefin polymerization when a reliable molecular control is achieved; in this respect, computational methods are a powerful tool to predict polymerization mechanisms like regio, stereoselectivity and molecular mass. In recent papers, we have reported that suitably activated bis(phenoxy-amine)Zr-dibenzyl complexes with the general structure of Chart 1, originally introduced by Kol, can be competent propene polymerization catalysts and are able to promote the “living” homo- and copolymerization of ethene, propene and higher 1-alkenes with the formation of block copolymers.