Two novel Ln 8 clusters bridged by CO 3 2- effectively convert CO 2 into oxazolidinones and cyclic carbonates.

It is difficult and challenging to design and construct high-nuclearity Ln(III)-based clusters due to the high coordination numbers and versatile coordination geometries of Ln(III) ions. Herein, two novel octanuclear Ln(III)-based clusters [Ln 8 (H 2 L - ) 4 (HL 2- ) 4 (NO 3 ) 6 (CO 3 ) 2 ](NO 3 ) 2 ·2CH 3 CN (Ln = Nd (1) and Sm (2)) have been synthesized under solvothermal conditions. The X-ray single analysis reveals that both 1 and 2 are octanuclear structures and the eight central Ln(III) ions are bridged by two CO 3 2- anions. Catalytic study revealed that 1 and 2 can effectively catalyze the cycloaddition reaction of CO 2 and aziridines or epoxides simultaneously under mild conditions. What is more, cluster 1, as a heterogeneous catalyst, can be reused at least three times without obvious loss in catalytic activity for coupling of CO 2 and epoxides. To our knowledge, cluster 1 is the first Ln(III)-based cluster catalyst used for the conversion of CO 2 with aziridines or epoxides simultaneously. This work provides a successful strategy to integrate high-nuclear Ln(III)-based clusters for CO 2 conversion, which may open a new space for the construction of multifunctional high-nuclear Ln(III)-based clusters as efficient catalysts for CO 2 conversion.