Highly Active and Isospecific Styrene Polymerization Catalyzed by Zirconium Complexes Bearing Aryl-substituted [OSSO]-Type Bis(phenolate) Ligands.

摘要: [OSSO]-type dibenzyl zirconium(IV) complexes 9 and 10 possessing aryl substituents ortho to the phenoxide moieties (ortho substituents, phenyl 2,6-dimethylphenyl (Dmp)) were synthesized characterized. Upon activation with dMAO (dried methylaluminoxane), complex was found promote highly isospecific styrene polymerizations ([mm] = 97.5%⁻99%) high molecular weights Mw up 181,000 g·mmol-1. When Dmp-substituted pre-catalyst 10/dMAO system used, highest activity, over 7700 g·mmol(10)-1·h-1, recorded involving formation of precisely polystyrenes [mm] more than 99%.