A Zinc(II) MOF for recognition of nitroaromatic explosive and Cr(III) ion

From the perspective of the environment, civilian safety and human health, it is important to selectively and sensitively detect hazardous substances in the running water. In the last few decades, using fluorescence, metal-organic frameworks (MOFs) have been used to detect lethal substances in the aqueous phase. Herein, a highly fluorescent MOF, SM-2, namely, {[Zn₂(pydc)₂(DMF)]·1.5DMF}_n, based on the ligand pyridine-2,5-dicarboxylic acid (H₂pydc), was synthesized by employing solvothermal conditions. The SM-2 was thoroughly characterized by crystallographic, PXRD, elemental, FTIR, and TG analysis. The single crystal data elucidated the exact structure of SM-2. Due to its better emission spectra, the fluorescence sensing behavior of SM-2 was checked in the aqueous medium. It was found that SM-2 could detect Cr³⁺ with high sensitivity and selectivity and serve as an excellent fluorescent sensor for TNP, among other interfering nitroaromatic compounds in aqueous media. Furthermore, UV–Visible and fluorescence data have demonstrated a plausible sensing mechanism. Thus, the fine-tuning of MOF for detecting hazardous substances in wastewater is challenging and must be addressed in future endeavours.