Zn-Salphen Acrylic Films Powered by Aggregation-Induced Enhanced Emission for Sensing Applications

Zn(II) complexes possess attractive characteristics for supramolecular chemistry, catalysis, and optoelectronic applications, while Zn-Salphen counterparts are also suitable as chemical sensors, although limited by solution-based to date. In this study, we report the synthesis of new polymers from methyl methacrylate, n-butyl acrylate, and a non-symmetrical Zn-Salphen complex. We show that this low-fluorescent complex exhibits aggregation-induced emission enhancement (AIEE) properties and that, the incorporation of AIEE complexes into a polymeric matrix make it possible to achieve fluorescent films with enhanced fluorescence suitable for sensing applications. As a proof of concept, these films could detect acetic acid, showing a decrease of up to 73% in the original fluorescence. Host/guest studies showed a subtle disruption of the emission in aggregates upon treatment with anion guests. These results indicate that an interaction between the guest and Zn-Salphen complex may occur, stabilizing or destabilizing the complex and causing a concomitant increase or decrease in emission.