Two novel Ln clusters bridged by CO effectively convert CO 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(HL)(HL)(NO) (CO)·2CHCN (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 anions. Catalytic study revealed that 1 and 2 can effectively catalyze the cycloaddition reaction of CO 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 and epoxides. To our knowledge, cluster 1 is the first Ln(III)-based cluster catalyst used for the conversion of CO with aziridines or epoxides simultaneously. This work provides a successful strategy to integrate high-nuclear Ln(III)-based clusters for CO conversion, which may open a new space for the construction of multifunctional high-nuclear Ln(III)-based clusters as efficient catalysts for CO conversion.