Synthesis and characterization of a new hydrazone-coumarin chemosensor for Fe3+ in a water-acetonitrile mixture

Abstract

A new coumarin-based fluorescent chemosensor, 3, incorporating a hydrazone (-NH-N=C-), was designed and synthesized. The chemosensor displayed higher affinity towards Fe 3+ in water-acetonitrile solution in the presence of other competing cations in emission and absorption essays. The binding stoichiometry between the chemosensor 3 and Fe 3+ was shown to occur in a 1:1 ratio, and the binding modes of the chemosensor towards Fe 3+ were identified through the emission response, 1 H NMR, FT-IR and molecular modelling studies. The hydroxyl and amine functionalities on 3 were recognized as possible binding sites. The chemosensor presented a limit of detection, a limit of quantification and the association constant of 0.45 µM, 1.50 µM and 3.01 × 10 1 M -1 , respectively.