A dicationic calix[4]pyrrole derivative and its use for the selective recognition and displacement-based sensing of pyrophosphate

Abstract

A new bis-pyridinium calix[4]pyrrole derivative is reported. This system forms a non-fluorescent complex upon exposure to the chromenolate anion. The resulting supramolecular ensemble binds the pyrophosphate anion with high affinity (K_a = (2.55 ± 0.12) × 10⁷ M⁻¹) in acetonitrile. It exhibits sensitive “turn-on” fluorescence when exposed to tetrabutylammonium pyrophosphate, and does so in preference to other anions, including the fluoride and phosphate anions.