Chemosensor properties of 7-hydroxycoumarin substituted cyclotriphosphazenes

Abstract

The newly synthesized cyclotriphosphazene cored coumarin chemosensors 5, 6, and 7 were successfully characterized by 1 H NMR, 31P NMR, and MALDI-TOF mass spectrometry. Additionally, the photophysical and metalsensing properties of the targeted compounds were determined by fluorescence spectroscopy in the presence of variousmetals (Li + , Na + , K + , Cs + , Mg 2+ , Ca 2+ , Ba 2+ , Cr 3+ , Mn 2+ , Fe 3+ , Co 2+ , Al 3+ , Hg + , Cu 2+ , Zn 2+ , Ag + , andCd 2+). The fluorescence titration results showed that compounds 5, 6, and 7 could be employed as fluorescent chemosensors for Fe 3+ ions with high sensitivity. The complex stoichiometry between final cyclotriphosphazene chemosensorsand Fe 3+ ions was also determined by Job’s plots.