Anion recognition by a novel Fipronil-based receptor: efficient deprotonation or stable intermolecular hydrogen bonding

Strong electron-deficient heterocycles of acetyl Fipronil (F3) was designed and synthesized, its ability for anion recognition was investigated by UV and NMR analyses. This novel Fipronil-based receptor F3 shows strong binding affinity with acetate (⩾107 M−1), phosphate or fluoride ion through efficient deprotonation. In addition, its interaction with chloride anion or other weak base anions through stable intermolecular H-bonding was also reported.