Conformation-Resolved Single-Luminogen Systems for Time-Dependent Multicolor Afterglow

Time-dependent multicolor afterglow enables temporal encoding of naked-eye distinguishable optical signals that cannot be achieved with static luminescence. However, available strategies to control the wavelength and color of time-dependent multicolor afterglow remain highly limited. Herein, we propose a conformation-resolved molecular design that successfully unlocks intrinsic dual-phosphorescence characteristics in single-luminogen systems, enabling dynamically color-tunable afterglow within the polymer matrix. Our strategy integrates flexible C-S-C rotors into a rigid pyrene core, allowing simultaneous stabilization of distinct emissive conformers with different triplet energy levels, specifically, a parallel conformer that can produce red phosphorescence and a perpendicular one yielding green phosphorescence. The asynchronous decay of these phosphorescent afterglows results in a visually perceptible emission color transition from red to yellow, and finally to green over a naked-eye distinguishable time scale, representing a rare paradigm of intrinsic, conformation-mediated dual-phosphorescence. Moreover, our systems are able to exhibit remarkable resistance to water, acids/bases, and organic solvents, as well as intrinsic UV-shielding capabilities, demonstrating that the time-dependent multicolor afterglow can readily integrate with diverse material functionalities, and is thus well suited for a wide range of application scenarios.