N-Salicyloyltryptamine: An efficient fluorescent turn-on chemosensor for F− and AcO− based on an increase in the rigidity of the receptor

The binding abilities of N-salicyloyltryptamine for various anions were investigated by UV–vis, fluorescence and 1H NMR titration spectra. The obtained results indicated that N-salicyloyltryptamine could selectively recognize biologically important F− and AcO− along with obvious changes in the absorption and emission spectra. Interestingly, addition of F− or AcO− to DMSO solution of N-salicyloyltryptamine caused a notable blueshift and remarkable enhancement in its fluorescence emission spectra.