Stereoselective polymerization of <i>rac</i>-lactide catalyzed by zwitterionic calcium complexes
Na Liu, Doudou Liu, Bo Liu, Hao Zhang, Dongmei Cui
Abstract
Two zwitterionic calcium complexes L<sup>1</sup>CaN(SiMe<sub>3</sub>)<sub>2</sub>(THF) (<bold>1</bold>) and L<sup>2</sup>CaN(SiMe<sub>3</sub>)<sub>2</sub> (<bold>2</bold>) <italic>via</italic> protolysis reaction were synthesized. At −75 °C, 1 gave a heterotactic sequence enriched polylactide, whilst 2 produced an isotactic sequence enriched polymer.
Topics & Concepts
TacticityPolymerizationSequence (biology)StereoselectivityChemistryCatalysisPolymerCalciumLactidePolymer chemistryCopolymerCrystallographyStereochemistryOrganic chemistryBiochemistrybiodegradable polymer synthesis and propertiesCarbon dioxide utilization in catalysisOrganometallic Complex Synthesis and Catalysis