Syndio- and Isoselective Coordinative Chain Transfer Polymerization of Styrene Promoted by ansa-Lanthanidocene/ Dialkylmagnesium Systems

International audienceCombinations of the discrete neutral allyl ansa-lanthanidocenes {Me2C(Cp)(Flu)}Nd[1,3- (SiMe3)2C3H3] and rac-{Me2C(Ind)2}Y[1,3- (SiMe3)2C3H3] with di(n-butyl)magnesium constitute efficient binary catalytic systems for the stereocontrolled coordinative chain transfer polymerization of styrene, yielding near-perfect syndio- and isospecific polystyrenes, respectively, with high activities and productivities. By adjusting the amount of di(n-butyl)magnesium, up to 200 polymer chains can be generated per lanthabide center, and good control of the molecular weight features enables the tailoring of low to medium molecular weight polymers