Azaindole-1,2,3-triazole conjugate as selective fluorometric sensor for dihydrogenphosphate

Abstract

A new receptor 1 has been designed and synthesized. The open cavity of 1 selectively recognizes H₂PO₄⁻ over a series of other anions in CH₃CN containing 0.01% DMSO by exhibiting a ratiometric change in emission. In sensing, the cooperativity of the azaindoles in 1 has been proved using the model compound 2. Also the interaction behavior of the nitrogen in the azaindole has been proved by considering compound 3, which did not show any discrimination towards the anions. Binding studies have been carried out using fluorescence, UV-vis, ¹H NMR and ³¹P NMR spectroscopic techniques.