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−, H 2 PO 4 - , SO 4 2 - , CH3COO−, NO 3 - 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.