Tb–TATAB crystalline organic framework material based on triazine tricarboxylic acid ligand: photophysical properties and fluorescence sensing applications†

A Tb-MOF complex based on triazine tricarboxylic acid ligands (2,4,6-tri(4-carboxylaniline)-1,3,5-triazine (H₃TATAB)) was constructed through the reaction of the rare earth metal Tb(III) and H₃TATAB. The complex featured a three-dimensional non-interpenetrating network structure constructed by the binuclear secondary building unit [Tb₂(CO₂)₆] and the H₃TATAB ligand. The complex exhibited excellent solvent stability, acid–base stability and thermal stability. Based on the fluorescence characteristics of the complex, it was found that the complex exhibited a sensitive fluorescence response and was recyclable for 7 kinds of nitroaromatic compounds (NACs) with different substituted groups, as well as heavy metal anions and cations (Cr₂O₇²⁻ and Fe³⁺). The fluorescence quenching behavior was preliminarily attributed to the synergistic effect of the CA and PET mechanisms.