Synthesis and optical properties of aggregation-induced emission (AIE) molecules based on the ESIPT mechanism as pH- and Zn2+-responsive fluorescent sensors

A series of schiff base derivatives with salicylaldehyde moieties were designed and synthesized. These materials exhibit typical AIE properties and high fluorescence quantum yields in an aggregated state based on the excited-state intramolecular proton transfer (ESIPT) mechanism. Then, the effect of substituted group types and positions on the fluorescence of these novel compounds was investigated through fluorescence spectra analysis and theoretical calculations. And it was found that the salicylaldehyde derivatives can be used as potential pH and Zn2+ sensors.