A Simple Colorimetric and Fluorescent Anion Sensor Based on 4-Amino-1,8-naphthalimide: Synthesis and its Recognition Properties

Abstract

A neutral 4-amino-1,8-naphthalimide-based anion receptor 1 containing a thiourea binding site was synthesized by simple steps. Its recognition capabilities for various anions were investigated by UV–vis, fluorescence and ¹H NMR spectra, which showed that compound 1 could effectively and selectively recognize F⁻  and AcO⁻  over other anions (Cl⁻ , Br⁻ , I⁻ , , , ). In particular, a moderate color change (from greenish yellow to bright yellow) and significant fluorescence quenching were synchronously observed upon addition of F⁻  or AcO⁻ . Nonlinear curve fitting and Job plot method established the formation of 1:1 hydrogen-bonding complex between compound 1 and the bound anions.

Keywords:

• Anion receptor
• Colorimetric sensor
• Fluorescence quenching
• Hydrogen bonding

Acknowledgements

Financial support from National Natural Science Foundation of China (No. 20672082) is gratefully acknowledged.