Multifunctional Dysprosium(III)–Organic Framework for Efficiently Catalyzing the Cycloaddition of CO2 and Knoevenagel Condensation under Mild Conditions

Two-dimensional (2D) materials with higher order in-plane nanoscale pores play a crucial role in innumerable applications, but their precise and reasonable preparation remains a huge challenge. Herein, we report the highly robust 2D dysprosium(III)–organic framework {[Dy(H2BDTP)(DMF)2]·2DMF·3H2O}n (NUC-101) with higher order in-plane nanoscale pores (15.2 × 6.4 Å2) (H5BDTP = 2,6-bis(2,4-dicarboxyphenyl)-4-(2H-tetrazol-5-yl)pyridine). After activation, the scarcely reported 2D host framework [Dy2(H2BDTP)2]n is of great interest due to that it not only contains voids of 15.2 × 11.7 × 6.4 Å3 but also is functionalized by free carboxyl, pyridinyl, and tetrazolyl groups in the upper and lower parts. Thanks to the excellent physicochemical properties including omnidirectional opening pores, ultrahigh porosity, larger specific surface area, and plentiful coexisting Lewis acid–base sites of open dinuclear Dy3+ ions, carboxyl, pyridinyl, and tetrazolyl groups, the cycloaddition of CO2 with epoxides and Knoevenagel condensation of malonitrile and aldehydes can be efficiently catalyzed by NUC-101a under comparatively mild conditions with high selectivity and turnover frequency. This work provides a valuable insight that the development of 2D functionalized nanoporous materials is more feasible for achieving the goal of catalytic applications.