Abstract

Chemosensors, for the recognition of anions have gained great attention in the field of supramolecular chemistry. Novel chromone-based colorimetric chemosensors, SN-1 and SN-2 are reported for the detection of F− and CN− ions. The structural characterization was done by1H-NMR, 13C-NMR, and UV-Vis spectroscopy. Colorimetric properties of the chemosensors were investigated in presence of different species (F−, AcO−, Br−, ClO−4, Cl−, HSO4−, I−, SCN−, and CN−). The chemosensors SN-1 and SN-2 displayed high selectivity towards CN− and F− ions. The limits of detection for SN-1 and SN-2 were found to be 5.5 × 10−8 and 3.3 × 10−8 for the CN− ion respectively. Chemosensor SN-2 showed greater response towards F− ion with low limit of detection 2.8 × 10−8 and its binding constant was assessed to be 2.5 × 104. The chemosensors could be used to detect the F− ion in real samples of toothpaste and in test strips. Density functional theory (DFT) study supported our experimental findings.