Solvent‐regulated Formation of Metal/Metal‐oxo Nodes in Two Indium Metal‐organic Frameworks: Syntheses, Structures, Selective Gas Adsorption and Fluorescence Sensor Properties

Two water‐stable indium metal‐organic frameworks, (NH 2 Me 2 ) 3 [In 3 (BTB) 4 ] ⋅ 12DMA ⋅ 4.5H 2 O (In‐MOF‐1) and (NH 2 Me 2 ) 9 [In 9 O 6 (BTB) 8 (H 2 O) 4 (DMSO) 4 ] ⋅ 27DMSO ⋅ 21H 2 O (In‐MOF‐2) (BTB=4,4′,4′′‐benzene‐1,3,5‐tribenzoate) with 3D interpenetrated structure has been constructed by regulating solvents. Structure analysis revealed that In‐MOF‐1 has a three‐dimensional (3D) structure with a single metal core, while In‐MOF‐2 features an octahedron cage constructed by three kinds of metal clusters to further form a 3D structure. The fluorescence investigations showed that In‐MOF‐1 and In‐MOF‐2 are potential MOF‐based fluorescent sensors to detect acetone and Fe 3+ ions in EtOH or water with high sensitivity, excellent selectivity, recyclability and a low limit of detection. Moreover, the fluorescence mechanisms of I n‐MOF‐1 and In‐MOF‐2 toward acetone and Fe 3+ ions were further explained. In addition, In‐MOF‐2 has higher thermal and framework stability than In‐MOF‐1 . The activated In‐MOF‐2 presents a high BET surface area of 998.82 m 2 g −1 and a pore size distribution of 8 to 16 Å. At the same time, In‐MOF‐2 exhibits high selective CO 2 adsorption for CO 2 /CH 4 and CO 2 /N 2 , respectively. Furthermore, the adsorption sites and adsorption isotherms were predicted using grand canonical Monte Carlo (GCMC) simulations, and the adsorption energy of the lowest‐energy adsorption configuration was calculated using molecular dynamics (MD) simulations.