New calix[4]arene based highly selective fluorescent probe for Al3+ and I-

This approach highlights the synthesis of a 2-hydroxy naphthalene functionalized calix[4] arene based fluorophoric Schiff base, C4SB. The ion-binding property of the C4SB fluoroionophore is probed with a number of cations and anions and the recognition events were monitored by UV-visible and fluorescence spectral changes. C4SB based on a photoinduced electron transfer mechanism exhibits a selective "turn-on" response towards Al3+ and a "turn-off" response for I- in the presence of other competing ions with certain observable spectral changes. The selective behavior of the probe is visualized in the presence of competing ions. The interference study reveals that Hg2+ causes some disturbance to the C4SB and Al3+ interaction. C4SB forms a (1 : 1) stoichiometric complex with both Al3+ and I- and their binding constants are calculated as 2.49 x 10(5) and 9.24 x 10(3), respectively. Moreover, the complexes were characterized through FT-IR spectroscopy.