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The reaction between carbon dioxide and epoxides is an attractive pathway for CO2-utilisation as it can lead to the formation of two different, yet valuable, products: cyclic and polymeric carbonates. In this review, the advancements made within this field are critically discussed with special attention to the potential of these two classes of compounds as green chemical products. First, an overview is provided of the various types of homogeneous and heterogeneous catalytic systems developed for achieving the reaction of carbon dioxide with epoxides with high activity and selectivity towards either the cyclic or the polymeric carbonate products. Then, the chemical and physical properties of the cyclic and polycarbonate products are discussed, focussing on the correlation between such properties and the potential applications of each class of compounds. Finally, the most relevant applications of these materials, both potential and industrially implemented, are critically reviewed covering the fields of polymer products, energy storage devices, and biomedical and pharmaceutical applications.

The reaction between carbon dioxide and epoxides is an attractive pathway for CO2-utilisation as it can lead to the formation of two different, yet valuable, products: cyclic and polymeric carbonates. In this review, the advancements made within this field are critically discussed with special attention to the potential of these two classes of compounds as green chemical products. First, an overview is provided of the various types of homogeneous and heterogeneous catalytic systems developed for achieving the reaction of carbon dioxide with epoxides with high activity and selectivity towards either the cyclic or the polymeric carbonate products. Then, the chemical and physical properties of the cyclic and polycarbonate products are discussed, focussing on the correlation between such properties and the potential applications of each class of compounds. Finally, the most relevant applications of these materials, both potential and industrially implemented, are critically reviewed covering the fields of polymer products, energy storage devices, and biomedical and pharmaceutical applications.

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.

International audience; The series of novel symmetric and asymmetric salphen cobalt (III) complexes with different counteranions (trichloroacetate, dinitrophenolate, pentafluorobenzoate and acetate) was synthesized and used as catalysts in copolymerization of CO2 with propylene oxide (PO) and cyclohexene oxide (CHO). Hexacoordinated structure of complexes adducts was found in solid phase. The effect of catalyst structure, temperature, CO2 pressure, catalyst/cocatalyst ratio on overall activity and selectivity was investigated. Synthesized salphen-Co (III) complexes were effective for both PO/CO2 and CHO/CO2 highly alternating copolymerization. Substitution of phenylene framework of salphen ligand by chlorine atom led to decrease of activity in PO/CO2 copolymerization. Complexes with trichloroacetate counteranion were shown to be the most active and selective in PO/CO2 copolymerization leading to poly(propylenecarbonate) with highest molar mass. On contrary, catalytic performance of salphen Co (III) complexes in CHO/CO2 copolymerization was almost independent on ligand structure and counteranion. Excellent selectivity to poly(cyclohexenecarbonate) was achieved even at 0.1 MPa CO2. MALDI-TOF analysis of polycarbonates was used to investigate the initiation step of the copolymerization.

Controlled routes to prepare polyesters and polycarbonates are of interest due to the widespread application of these materials and the opportunities provided to prepare new copolymers. Furthermore, ring-opening copolymerization may enable new poly(ester–carbonate) materials to be prepared which are inaccessible using alternative polymerizations. This review highlights recent advances in the ring-opening copolymerization catalysis, using epoxides coupled with anhydrides or CO2, to produce polyesters and polycarbonates. In particular, the structures and performances of various homogeneous catalysts are presented for the epoxide–anhydride copolymerization. The properties of the resultant polyesters and polycarbonates are presented and future opportunities highlighted for developments of both the materials and catalysts.

Some of the most active catalysts for carbon dioxide and epoxide copolymerization are dinuclear metal complexes. Whilst efficient homodinuclear catalysts are known, until now heterodinuclear catalysts remain unreported. Here, a facile, in situ route to a catalyst system comprising a mixture of homo- and heteronuclear Zn–Mg complexes is presented. This catalyst system shows excellent polymerization control and exhibits significantly higher activity than the homodinuclear catalysts alone or in combination.