Nanoporous Zn^II/Tb^III–Organic Frameworks for CO₂ Conversion

Creative assembly of bimetallic [Zn^IITb^III(CO₂)₃(H₂O)] clusters and the desigened bifunctional ligand of H₆TDP engendered one highly robust anionic heterometallic framework {[(CH₃)₂NH₂]­[Zn^IITb^III(TDP)­(H₂O)]·3DMF·3H₂O}_n (NUC-7), which featured two types of nanochannels decorated with density open metal sites and free oxygen atoms on the wall. To the best our knowledge, NUC-7 represented one novel kind of heterometallic Zn^II/Ln^III-organic 3D honeycomb MOFs with exposed tetra-coordinated Zn^II-metal sites as Lewis acid sites. Subsequent studies indicated that NUC-7 could highly adsorb CO₂ and catalyze the cycloaddition of various epoxides into related carbonates with the help of cocatalyst TBAB under lukewarm conditions of 1 atm and 80 °C. Meanwhile, NUC-7 exhibited the effectively selective sensitivity for discriminating Fe³⁺ in aqueous solution by luminescence quenching. It could be inferred that the excellent characteristics including large void volume, high porosity, active open metal sites, and uncoordinated carboxylate oxygen atoms as Lewis acid and base sites rendered NUC-7 one ideal platform for gas reservoir, specific catalyst, and luminescence sensing.