Benzimidazole functionalized tripodal receptor for selective recognition of iodide

A novel tripodal fluorescent receptor with benzimidazole motifs as signaling unit is reported. The receptor can selectively bind iodide anion with drastic change in its fluorescence and UV/Vis spectra, while addition of other anions (F−, Cl−, Br−, H2PO4-, SO42-, CH3COO−, NO3- and CN−) does not show any significant change. The formation of receptor-iodide hydrogen bonded complex is proved by NMR titration of the receptor in the presence of iodide anion.