Styrene Polymerization Behavior of Phenoxy−Imine Ligated Ti Complexes/MAO: Formation of Highly Isotactic and Syndiotactic PS

Unique styrene polymerization behavior of bis(phenoxy−imine) Ti complexes (Ti−FI catalysts) combined with dried MAO (DMAO) was revealed. Upon activation with DMAO at 20 °C, non-fluorinated Ti−FI catalysts 1 and 2 produce highly syndiotactic polystyrene (sPS, Tm 275 °C (1), 279 °C (2)), whereas fluorinated Ti−FI catalysts 3 and 4 form highly isotactic PS (iPS, Tm 224 °C (3), 213 °C (4)). Interestingly, the fluorinated Ti−FI catalysts can produce an iPS/sPS mixture by varying polymerization conditions.