Isothermally reversible fluorescence switching of a mechanochromic perylene bisimide dye.

Isothermally rewritable fluorescence mechanochromism has been realized for a perylene bisimide dye with bulky and flexible substituents. Fluorescent patterns drawn by mechanical stimuli can be erased by thermal stimuli, treatment with solvent vapors, or spontaneous structural transition from orange-fluorescent to green-fluorescent states. The isothermal fluorescence switching of solid dye films is applicable to displays and sensory materials.