Pressure‐Treated Luminescent and Structural Evolution With Irreversible Control of Emission in Through‐Space Charge Transfer Emitter

ABSTRACT Through‐space charge transfer (TSCT) is gaining prominence for developing solid‐state luminophores, owing to its tunable and dynamically regulable luminescence. In this work, a novel TSCT emitter with a spatially segregated donor–acceptor (D–A) architecture is designed and synthesized, which exhibits high‐efficiency blue‐violet emission at 410 nm with a narrow 37 nm FWHM and minimal Stokes shift due to molecular rigidity and suppressed structural reorganization. DMAC‐CBO crystal demonstrates remarkable mechanochromism through grinding‐induced amorphization and a pronounced piezochromic response showing a 156 nm redshift in the range of 14.0 GPa due to the decreased distance between D and A units. As a result, pressure‐induced the enhancement of intramolecular and intermolecular interactions promote excimer formation, leading to redshifted emission and enabling the modulation of the dominant emissive state from a local excited (LE) state to an excimer. Impressively, upon decompression from high pressure, DMAC‐CBO retains a metastable phase, resulting in irreversibly shifted and broadened luminescence derived from excimers. These findings not only demonstrate that pressure can continuously regulate the distance between D and A units of TSCT‐based materials, but also effectively establish a structure‐property framework for TSCT‐based smart materials with tunable and persistent emission, offering promising applications in data storage, sensing, and optoelectronics.