Dual-Stimuli-Responsive Fluorescent Supramolecular Polymer Based on a Diselenium-Bridged Pillar[5]arene Dimer and an AIE-Active Tetraphenylethylene Guest

We report a new strategy to construct a multi-stimuli-responsive fluorescent supramolecular polymer by the strong host–guest interactions between a diselenium bond-bridged pillar[5]arene dimer and an AIE-active tetraphenylethylene (TPE)-containing neutral guest bearing two imidazole terminal binding sites. The resulting supramolecular polymer shows a remarkable fluorescence emission decrease at low concentration. Significantly, the diselenium bonds introduced into the supramolecular polymer serve as redox-responsive building blocks. Upon addition of reductants, the supramolecular polymer depolymerized owing to the cleavage of the covalent diselenium bonds in the system. On the other hand, competitive guests such as adiponitrile, which bind strongly with pillar[5]arenes, could lead the disassembly of the polymer to oligomers without breaking any covalent bonds in the system. These two types of depolymerization approaches can both result in the fluorescence intensity recovery of the system to a certain extent, which will hopefully enrich the methodology toward the construction of smart supramolecular polymeric materials with different properties.