Photoactivation‐Induced Emission Enhancement in Benzosilole‐Based Fluorescent Conjugated Microporous Polymer Microspheres with Converse‐Photobleaching Behavior

Abstract Photo‐responsive porous materials have demonstrated their versatility in various areas. However, photoactivation in the fluorescent conjugated microporous polymer (CMP) microspheres is barely reported. Herein, a facile synthesis of benzosilole‐based CMPs with uniform microspheric morphology and their unprecedented photoactivated fluorescence enhancement as converse‐photobleaching behavior are reported. By simple ultraviolet irradiation, the fluorescence of the CMP microspheres as the dispersion in various solvents is enhanced up to 60‐fold. More importantly, the photoactivation‐induced emission enhancement is carefully revealed to originate from the renovation of the ubiquitous defects by solvent molecule adsorption, photo‐dissociating, photo‐interparticle coupling, and photochemical reactions, supported by control experiments, theoretical calculations, and molecular dynamics simulations. The systematic elucidation of the CMP defects can open a new door to developing photo‐responsive polymers for various applications.