Selective detection of fluoride and hydrogen sulfate anions by pyrimidine-based fluorescence chemosensor

Abstract

The binding and sensing abilities of pyrimidine based fluorescence chemosensor L towards different anions such as F^-, Cl^-, Br^-, I^-, NO₃^-, ClO₄^-, H₂PO₄^- and HSO₄^- have been examined by fluorescence spectroscopy in DMSO-H₂O (7: 3, v/v). Upon successive addition of various anions to DMSO-H₂O solutions of L; quenching in emission fluorescence is observed at 480 nm. Analysis of fluorescence emission changes suggested the formation of 1:1 complex of L with the anions. From the fluorescence binding constant data, it is found that L form strong complexes with F^- and HSO₄^- ions through H-bonding interactions. The selective response of F^- over other halides and HSO₄^- amongst other oxo-anions towards L may be explained on the basis of photo-induced electron transfer process.