Syndio- and isoselective coordinative chain transfer polymerization of styrene promoted by ansa-lanthanidocene/ dialkylmagnesium systems

Abstract

Combinations of the discrete neutral allyl ansa-lanthanidocenes {Me 2C(Cp)(Flu)}Nd[1,3- (SiMe3)2C3H 3] and rac-{Me2C(Ind)2}Y[1,3- (SiMe 3)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. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.