Two Benzothiadiazole-Based Compounds As Multifunctional Fluorescent Sensors For Detection Of Organic Amines And Anions

Two benzothiadiazole-based compounds, namely 4,7-di(1H-1,2,4-triazol-1-yl)benzo-[2,1,3]thiadiazole (1) and 4,7-di(1H-pyrazol-1-yl)benzo-[2,1,3]thiadiazole (2), have been constructed with Cu-catalyzed cross-coupling reactions. The fluorescence studies show that compound 1 has high selectivity and sensi-tivity toward TEA (triethylamine), EDA (ethylenediamine), TMEDA (N,N,N',N'-tetramethylethylenedi-amine), MnO4- and ClO- by fluorescence quenching, and compound 2 also has high selectivity and sensitivity toward TEA and TMEDA via fluorescence quenching. The calculated detection limits of 1 for TEA, EDA, TMEDA, MnO4- and ClO- are 0.129, 0.635, 0.320, 9.820 and 12.740 mu M, respectively. Meanwhile, the detection limits of compound 2 for TEA and TMEDA are 0.400 and 0.278 mu M, respectively. Interestingly, compounds 1 and 2 are the first fluorescent sensors for the selective recognition of TMEDA. (C) 2021 Elsevier Ltd. All rights reserved.