Light and Heat‐Driven Flexible Solid Supramolecular Polymer Displaying Phosphorescence and Reversible Photochromism

Abstract Herein, a type of light‐ and heat‐driven flexible supramolecular polymer with reversibly long‐lived phosphorescence and photochromism is constructed from acrylamide copolymers with 4‐phenylpyridinium derivatives containing a cyano group (P‐CN, P‐oM, P‐mM), sulfobutylether‐β‐cyclodextrin (SBCD), and polyvinyl alcohol (PVA). Compared to their parent solid polymers, these flexible supramolecules based on the non‐covalent cross‐linking of copolymers, SBCD, and PVA efficiently boost the phosphorescence lifetimes (723.0 ms for P‐CN, 623.0 ms for P‐oM, 945.8 ms for P‐mM) through electrostatic interaction and hydrogen bonds. The phosphorescence intensity/lifetime, showing excellent responsiveness to light and heat, sharply decreased after irradiation with a 275 nm flashlight or sunlight and gradually recovered through heating. This is accompanied by the occurrence and fading of visible photochromism, manifesting as dark green for P‐CN and pink for P‐oM and P‐mM. These reversible photochromism and phosphorescence behaviors are mainly attributed to the generation and disappearance of organic radicals in the 4‐phenylpyridinium derivatives with a cyano group, which can guide tunable luminescence and photochromism.