Chemosensor properties of 7-hydroxycoumarin substituted cyclotriphosphazenes

The newly synthesized cyclotriphosphazene cored coumarin chemosensors 5, 6, and 7 were successfully characterized by (1) H NMR, (31) P 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 (+) , Mg (2+) , Ca (2+) , Ba (2+) , Cr (3+) , Mn (2+) , Fe (3+) , Co (2+) , Al (3+) , Hg (+) , Cu (2+) , Zn (2+) , Ag (+) , and Cd (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 chemosensors and Fe (3+) ions was also determined by Job’s plots.