A series of homonuclear rare-earth (RE) metal complexes (1 Y , 2 Yb , 3 Nd , and 4 La ) and heteronuclear RE–Zn complexes (1 Y–Zn , 3 Nd–Zn , and 5 Sm–Zn ) stabilized by ethanolamine-bridged bis­(phenolato) ligands was prepared and structurally characterized. Heteronuclear complexes are assembled through bridging acetate ligands, and their formation and characterization add to the diversity of 3d–4f complexes. Their activities in mediating reactions of CO2 and epoxides were evaluated and compared. Heteronuclear RE–Zn complexes found application in the copolymerization of cyclohexene oxide and CO2, giving rise to acetate-group-capped copolymers. Homonuclear complexes showed good activity in catalyzing the cycloaddition of variously monosubstituted epoxides and CO2 (1 bar), generating cyclic carbonates in 65–96% yield. For sterically hindered disubstituted epoxides, good yields of 60–91% were achieved in the presence of 10 bar CO2.

No abstract