Synthesis and crystal structure of a novel pyridine acylhydrazone derivative as a “turn on” fluorescent probe for Al3+

Abstract

A novel acylhydrazone-based fluorescent probe HL was synthesized and characterized by 1H NMR, 13C NMR, mass spectrum (MS) and x-ray diffraction analysis. HL showed high selectivity and sensitivity towards Al3+ over other metal ions based on excited-state intramolecular proton transfer (ESIPT) and photo-induced electron transfer (PET) processes with a low detection limit (2.14 × 10−8 M) and reasonable pH application range (4.0–7.5). HL and Al3+ formed a 1:1 complex, leading to a remarkable fluorescence enhancement, which was confirmed by Job’s plot experiments, 1H NMR and MS. Fluorescence titration experiments showed the fluorescence intensity of HL had good linearity with Al3+ concentration and can be used to detect Al3+ in real water samples.