Synthesis and optical properties of Schiff base derivatives based on 2-(2-hydroxyphenyl)benzothiazole (HBT) and application in the detection of NH.

Four 2-(2-hydroxyphenyl)benzothiazole-based Schiff base derivatives incorporating different substituents were synthesized. Their optical properties were characterized by UV-visible and fluorescence spectra. The electron-withdrawing and electron-donating actions of substituents can change the orbital energy level distributions of molecules resulting in the difference of their luminescence properties. And the fluorescence microscopic images showed that these derivatives had different aggregation behaviors to form aggregates of different shapes. Furthermore, compound HBT-4 has been proved to have excellent recognition performance for NH in real aqueous solution. Finally, HBT-4 could be prepared into a simple test paper as an efficient tool for the rapid detection of NH.