A novel coumarin-pyrazole-triazine based fluorescence chemosensor for fluoride detection via deprotonation process: Experimental and theoretical studies

Abstract

A novel fluorescence coumarin-pyrazole-triazine based chemosensor (CPT) bearing 5-hydroxypyrazole as a receptoric part was synthesized and characterized by using IR, 1H/13C NMR and HRMS for the purpose of recognition of anions in DMSO. The most stable tautomeric form of CPT was determined by experimental techniques and theoretical calculations. The selectivity and sensitivity of CPT towards anions (CN−, F−, Cl−, Br−, I−, AcO−, HSO4−, H2PO4− and ClO4−) were determined using spectrophotometric and 1H NMR titration techniques as the experimental approach, and the results were explained by employing theoretical calculations. It was found to be suitable for the selective detection of F− in the presence of CN− and AcO− as competing anions. In addition, CPT exhibits significant “light-up” effect after interaction with TFA in CH2Cl2.