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

Abstract

The binding and sensing abilities of pyrimidine based fluorescence chemosensor <strong>L</strong> 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 <strong>L</strong>; quenching in emission fluorescence is observed at 480 nm. Analysis of fluorescence emission changes suggested the formation of 1:1 complex of <strong>L</strong> with the anions. From the fluorescence binding constant data, it is found that <strong>L</strong> 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 <strong>L</strong> may be explained on the basis of photo-induced electron transfer process.