Anion recognition ability of a novel azo dye derived from 4-hydroxycoumarin

The anion recognition ability of a novel azo dye derived from 4-hydroxycuomarin (L) was investigated by experimental (UV–vis, fluorescence and 1H NMR) and theoretical [(B3LYP/6-31G(d,p)] methods. Among the surveyed anions, the receptor L showed both naked-eye detectable color and spectral changes in the presence of F−, AcO− and H2PO4− due to the formation of hydrogen bonding complexes followed by deprotonation between these anions and L.