A benzothiazole-based sensor for pyrophosphate (PPi) and ATP: mechanistic insight for anion-induced ESIPT turn-on

Abstract

A benzothiazole derivative 2 bearing two 2,2′-dipicolylamine (DPA) groups was examined for its zinc-binding and subsequent anion sensing properties. The study revealed the anion sensing mechanism of polyphosphate anions via sequential binding to two zinc centers, on the basis of both ¹H NMR and mass spectral evidence. The mechanistic insight would provide valuable information for the future design of new excited state intramolecular proton transfer (ESIPT) sensors. In addition, the zinc complex exhibited solvent-switchable selectivity, responding to pyrophosphate (PPi) in EtOH and adenosine 5′-triphosphate (ATP) in water.