Quantifying CO₂ Insertion Equilibria for Low-Pressure Propene Oxide and Carbon Dioxide Ring Opening Copolymerization Catalysts.

While outstanding catalysts are known for the ring-opening copolymerization (ROCOP) of CO₂ and propene oxide (PO), few are reported at low CO₂ pressure. Here, a new series of Co(III)M(I) heterodinuclear catalysts are compared. The Co(III)K(I) complex shows the best activity (TOF = 1728 h^-1) and selectivity (>90% polymer, >99% CO₂) and is highly effective at low pressures (