A “Simple” Donor-Acceptor AIEgen with Multi-Stimuli Responsive Behavior

At present, there is still an urgent demand for novel smart materials that can achieve a diverse range of practical applications in synthetic material area. Herein, we developed a simple but versatile aggregation-induced emission luminogen (1) with a donor-acceptor structure and pronounced intramolecular charge transfer property. Compound 1 showed a remarkable color change in sensitive response to polarity change making it to serve as a promising imaging probe for detecting environmental polarity in cells and selective visualization of lipid droplets in live tissues. Additionally, this compound exhibited a wide range of thermoresponsive behavior with ratiometric luminescence change and noticeable fluorescence color switching. It also can respond to anisotropic shearing force and isotropic hydrostatic pressure with prominent but contrast luminescence conversion due to the distinct disturbance of the weak intermolecular interactions and charge transfer processes. Meanwhile, compound 1 was sensitive to external electric stimulus and displayed reversibly three-color switched electrochromism and on-to-off electroluminochromism. Such property allowed the fabrication of high-performance non-doped OLED with a high external quantum efficiency of 5.22%. The present results may offer an important guideline for multifunctional molecular design and provide an important step forward to expand the real-life applications of AIE-active smart materials.