A Dual-Responsive Fluorescent Compound Exhibiting Turn-On Mechanoresponsive and Solvatochromism for Rewritable Optical Data Storage

A novel mechanoresponsive and solvatochromic luminescent compound (<b>MO</b>-<b>HBI</b>) was designed by combining an ESIPT-active donor with a benzophenone acceptor, exhibiting reversible luminescence switching and aggregation-induced emission enhancement. The solvatochromic behavior of <b>MO</b>-<b>HBI</b> was systematically studied in solvents of varying polarity, revealing a distinct bathochromic shift in both absorption and fluorescence emission, with pronounced sensitivity attributed to the presence of a carbonyl group. Upon mechanical stimulation, <b>MO</b>-<b>HBI</b> undergoes a crystalline-to-amorphous phase transition, leading to a significant fluorescence increase and color change from faint yellow to yellow-green. Structural analysis and DFT computation confirm that mechanoresponsive property originates from disrupted intermolecular hydrogen bonding and altered molecular packing. The emission can be fully recovered through solvent fuming or thermal annealing. Based on this, a rewritable optical storage system was developed using <b>MO</b>-<b>HBI</b> coated paper, allowing erasable data display triggered by mechanical and vapor stimuli. This study provides a promising strategy for designing high-contrast, reversible mechanoresponsive systems for sensing and information storage applications.