Chemosensor properties of 7-hydroxycoumarin substituted cyclotriphosphazenes?

Abstract

The newly synthesized cyclotriphosphazene cored coumarin chemosensors 5, 6, and 7 were successfully characterized by 1H NMR, 31P NMR, and MALDI-TOF mass spectrometry. Additionally, the photophysical and metal sensing properties of the targeted compounds were determined by fluorescence spectroscopy in the presence of various metals (Li+ , Na+ , K+ , Cs+ , Mg2+ , Ca2+ , Ba2+ , Cr3+ , Mn2+ , Fe3+ , Co2+ , Al3+ , Hg+ , Cu2+ , Zn2+ , Ag+ , and Cd2+) . The fluorescence titration results showed that compounds 5, 6, and 7 could be employed as fluorescent chemosensors for Fe3+ ions with high sensitivity. The complex stoichiometry between final cyclotriphosphazene chemosensors and Fe3+ ions was also determined by Job's plots.