Highly isoselective coordination polymerization of ortho-methoxystyrene with β-diketiminato rare-earth-metal precursors

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>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. Name your poison: The title reaction has been achieved for the first time by using a β-diketiminato cationic rare-earth-metal species. High activity and excellent isoselectivity are observed. The Lewis-basic methoxy group does not poison the Lewis-acidic metal center but activates the polymerization through σ-π chelation to the active species.