Dual-Function Lanthanide–Organic Frameworks Based on a Zwitterionic Ligand as a Ratiometric Thermometer and a Selective Sensor for Nitroaromatic Explosives

Lanthanide–organic frameworks have been extensively exploited as efficient chemical sensors for versatile analyte detection. In this work, based on a zwitterionic ligand, N-(4-carboxybenzyl)-4-(4-carboxyphenyl)­pyridinium chloride, a family of lanthanide–organic frameworks, [Ln2(L)3·NO3]·(NO3)2·xsolvent [Ln-MOF (Ln = Eu3+ and Tb3+)], has been synthesized and structurally characterized. The obtained Eu3+/Tb3+-mixed Tb99.9/Eu0.1-MOF can serve as a ratiometric thermometer with high sensitivity from 247 to 377 K. For its strong luminescence and good water stability, Eu-MOF can be developed as a selective and sensitive sensor for detecting the nitroaromatic explosive 2,4,6-trinitrophenol with a low detection limit of 82.35 nM.