A highly selective fluorescent chemosensor for Al(III) ions based on 2-hydroxy-1-naphthaldehyde derivative

Abstract

This manuscript reports the synthesis and fluorescent chemosensor property of a Schiff base derivative, 4-[(2-hydroxy-1-naphthyl) methylideneamino]benzoic acid (H2L). The fluorescence spectrum shows that H2L exhibits a highly selective and sensitive recognition for Al3+ ions in N,N′-dimethylformamide/water (DMF/H2O, 1/1, v/v). The fluorescence titration experiments and electrospray ionization mass spectrometry (ESI–MS) show that H2L and Al3+ ions form a 1:1 complex. 1H NMR titration results show that H2L coordinates to Al3+ ions with carboxylate, hydroxyl groups, and imine groups and the probable sensing mechanism may be the excited-state intramolecular proton transfer (ESIPT) process.