Group 3 and 4 single-site catalysts for stereospecific polymerization of styrene

The present review aims at a comprehensive survey of controlled stereospecific styrene polymerization by single-site catalysts to give syndiotactic and isotactic polystyrene. The early transition metals (groups 3 and 4) complexes that were successfully applied as catalyst precursors are reviewed. Catalytic performances and mechanistic insights, in particular in the stereoregulation phenomenon, are discussed.