Chromium-Catalyzed CO₂–Epoxide Copolymerization

Iminopyrrole, aminopyrrole, and aminophosphine ligands were complexed with various chromium sources, producing eight complexes that were tested for their catalytic behavior toward epoxide–CO₂ copolymerization. As elucidated by MALDI-TOF-MS, copolymerizations afforded polycarbonates and poly­(ether-carbonates) exhibiting linear or cyclic topologies