Unlocking Enhanced Switching Capacities in DASA-Functionalized Coordination Complex

The fusion of photoswitchable molecules with coordination chemistry paves the way for the development of smart materials. This study explores the potential of Donor-Acceptor Stenhouse Adducts (DASAs), a novel class of organic photoswitches characterized by negative photochromism and visible-light responsiveness. To enhance their functional capabilities and overcome inherent limitations, we adopt a dual-site coordination approach, synthesizing the first well-defined crystalline coordination complex from DASAs. This complex exhibits significantly enhanced solid-state thermo- and photoswitching properties compared to the parent DASA ligand. Notably, the dynamic behavior of our coordination material enables distinct responses to various stimuli, creating multiple accessible states with tunable physical properties. These include stepped color changes and fluorochromism, which are not present in the individual components, thus highlighting new functionalities upon coordination. The ability to modulate these properties through external stimuli provides a versatile platform for applications in rewritable materials, information encoding, and molecular devices. As a demonstration, we show that "water" can serve as ink and "light" enables convenient erasable writing. This marks a significant advance in sustainable and environmentally conscious materials.