Chemorobust 4p-5p {InPb}-organic framework for efficiently catalyzing cycloaddition of CO2 with epoxides and deacetalization-Knoevenagel condensation

Due to that the high charge density and small radius render In 3+ cation a stronger Lewis acidity, multifunctional nanoporous In-MOFs have become one of the most promising catalysts for their high activity. Herein, the solvothermal self-assembly by employing 2,4,6-tri (2,4-dicarboxyphenyl)pyridine (H 6 TDP) as organic linker leads to a robust honeycomb skeleton of {[(CH 3 ) 2 NH 2 ][In III Pb II (TDP) (H 2 O)]⋅3DMF⋅3H 2 O} n ( NUC-52 ) with the merits of nanoscopic channels, high porosity (61.3%), large specific surface area, and thermal stability. To the best of our knowledge, this is the first 4p-5p heterometallic {In III Pb II } cluster-based nano-porous host framework, whose activated state possesses the coexistence of Lewis acid-base sites including 7-coordinated Pb 2+ ions, 4-coordinated In 3+ ions, uncoordinated carboxyl oxygen atoms, and N pyridine atoms. Performed catalytic experiments exhibited that activated NUC-52 owned the high catalytic activity on the cycloaddition reactions of styrene oxide with CO 2 under mild conditions with excellent turnover number (2475) and turnover frequency (619 h −1 ). Moreover, activated NUC-52 could greatly accelerate the deacetalization-Knoevenagel condensation reactions of benzaldehyde dimethyl acetal and malononitrile. Hence, this work lays down the groundwork for constructing heterometallic cluster-based nanoporous MOFs with excellent Lewis acidic catalysis and chemical stability, which should be ascribed to the reasonable coordination arrangement between organic ligands and distinct metal ions according to the hard–soft acid–base (HSAB) theory. A highly robust {InPb}-organic framework with Lewis acid-base bifunctional features exhibits high catalytic activity on the cycloaddition reactions of epoxides with CO 2 and deacetalization-Knoevenagel condensation reactions. • InPb-cluster-based honeycomb framework of NUC-52 can highly catalyze the cycloaddition of CO 2 and deacetalization-Knoevenagel condensation. • Performed catalytic experiments exhibited that activated NUC-52 owned the high catalytic activity on the cycloaddition reactions of styrene oxide with CO 2 under mild conditions with excellent turnover number (2475) and turnover frequency (619 h -1 ). Moreover, activated NUC-52 could greatly accelerate the deacetalization-Knoevenagel condensation reactions of benzaldehyde dimethyl acetal and malononitrile.