Aromatic dicarboxylates induced structural diversity of Cd^II metal–organic frameworks from a 2D layer to a 3D pillar-layer network for fluorescence sensing of cations, anions and <scp>l</scp>-serine

Two distinct Cd^II metal-organic frameworks (MOFs) with the formulas {[Cd(BBZB)(oba)]·H₂O}_<i>n</i> (JXUST-45) and {[Cd(BBZB)(bpdc)]·2H₂O}_<i>n</i> (JXUST-46) featuring 2D layer and 3D pillar-layer structures, respectively, have been prepared, which were regulated by aromatic dicarboxylate ligands (4,4'-diphenyl ether dicarboxylic acid, H₂oba; 4,4'-biphenyldicarboxylic acid, H₂bpdc; and 4,7-bis(1<i>H</i>-benzimidazol-1-yl)-2,1,3-benzothiazole, BBZB). JXUST-45 and JXUST-46 can be considered good fluorescence sensors toward Al³⁺, Fe³⁺, AcO^-, Cr₂O₇^2-, and L-serine. Meanwhile, JXUST-45 and JXUST-46 have good thermal stability and recovery ability. In addition, JXUST-45- and JXUST-46-based fluorescent test papers and light-emitting diode lamps have been further developed to realize naked-eye detection of Al³⁺, Fe³⁺, AcO^-, Cr₂O₇^2-, and L-serine, which has great potential for practical applications.