Highly Isoselective Coordination Polymerization of <i>ortho</i>‐Methoxystyrene with β‐Diketiminato Rare‐Earth‐Metal Precursors

Abstract

Abstract Stereoselective coordination/insertion polymerization of the polar ortho ‐methoxystyrene has been achieved for the first time by using the cationic β‐diketiminato rare‐earth‐metal species. High activity and excellent isoselectivity ( mmmm &gt;99 %) were acheived. The unmasked Lewis‐basic methoxy group does not poison the Lewis‐acidic metal center, but instead activates the polymerization through σ‐π chelation to the active species together with the vinyl group, thus lower the coordination and activation energies as compared with those of styrene derivatives lacking the methoxy group.