Zn^II–2,2′:6′,2″‐Terpyridine‐Based Complex as Fluorescent Chemosensor for PPi, AMP and ADP

Abstract

Abstract A new Zn II –2,2′:6′,2″‐terpyridine complex, derivatized with a coumarin moiety ( L 1 Zn ), acts as a fluorescent chemosensor for different biologically important phosphates like PPi, AMP and ADP in mixed aqueous media. Depending on the proportion of the aqueous fraction present in the solvent mixture, L 1 Zn shows a preference for different phosphate moieties at physiological pH. In an aqueous acetonitrile (2:3, v/v) medium this reagent shows a preference for AMP as compared to ADP, ATP and PPi. The binding affinities of L 1 Zn with different phosphate ions and associated shifts in the electronic spectra were rationalized by DFT calculations. Such an example of a receptor that is selective for AMP under physiological conditions is rare in the literature.