“…Utilization of CO 2 as the C1 source for the production of valuable chemicals is attracting increasing interest because CO 2 is inexpensive, nontoxic, and abundant. − One promising method is the copolymerization of CO 2 and epoxides, which produces polycarbonates that have found many applications in packaging, agricultural, and biomedical industries. − A number of catalysts have been developed for copolymerization, including complexes of zinc, − cobalt, − chromium, − magnesium, − iron, − nickel, − and rare-earth metals. − Among these examples, cobalt salen complexes have been reported to show good activity and selectivity (Scheme , left). Coates et al reported the first Co(III) salen complex, which gave >99% selectivity to poly(propylene carbonate) .…”