Multifunctional elastic benzoxazole derivative crystals for advanced optoelectronic applications

We report a novel benzoxazole derivative, 1,4-bis(benzo[d]oxazol-2-yl)naphthalene (BBON), exhibiting exceptional multifunctional properties for advanced optoelectronic applications. BBON crystals demonstrate remarkable multidirectional bending and twisting at room temperature and retain elasticity under extreme conditions, such as exposure to liquid nitrogen, showcasing their durability. These crystals can be crafted into complex mesh and lantern shapes, highlighting their versatility for flexible and wearable technologies. Under high pressure, BBON exhibits significant piezochromic shifts, with the emission wavelength shifting from 477 to 545 nm upon pressure increase. BBON crystals, with a high quantum yield of 72.26%, exhibit excellent optical waveguide performance: 0.38 dB/cm when straight and 0.56 dB/cm when bent. These properties make them ideal for smart sensors and flexible electronic devices. Single-crystal analyses reveal that molecular stacking and intermolecular interactions are crucial to their elastic and piezochromic properties, providing insights for the design of future responsive materials.