A fluorescence red-shift and turn-on sensor for acetylacetone derived from ZnII-based metal–organic framework with new topology

Abstract

A three-dimensional metal–organic framework, namely {[Zn₃(BIBT)(BTC)_5/3(μ₃-OH)]·solvents}_n (JXUST-4), has been synthesized by using Zn^II ions, and BIBT and H₃BTC ligands (BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole and H₃BTC = 1,3,5-benzenetricarboxylic acid). JXUST-4 shows a new (3,3,7)-connected topology net containing a trinuclear Zn^II cluster, uncoordinated N atoms of BIBT and uncoordinated carboxylate O atoms of H₃BTC, which facilitates the interaction between the framework and analytes. Fluorescence studies indicate that JXUST-4 generates light yellow luminescence, which could be ascribed to ligand-centered emission. More importantly, JXUST-4 could be viewed as an effective fluorescent sensor toward acetylacetone through an obvious fluorescence red-shift with high sensitivity, efficient selectivity, and outstanding recycling capacity. Furthermore, the possible sensing mechanism of JXUST-4 toward acetylacetone is due to electron transfer and weak interactions between the analyte and framework.