High-Contrast On/Off Fluorescence Switching via Reversible E-Z Isomerization of Diphenylstilbene Containing the α-Cyanostilbenic Moiety

Fluorescence switching or modulation of pi-conjugated molecules is of great interest in the area of optoelectronic materials science and technology because of their promising applications. However, the concentration fluorescence quenching problems commonly associated with conventional pi-conjugated molecules in the solid state were occasionally an obstacle to use of pi-conjugated molecules in high-contrast memory storage devices. We designed an. synthesized a novel class of fluorescence switching pi-conjugated molecule, (Z)-CN-MBE, exhibits a reversible Photo/thermal E/Z isomerization process, accompanied by a remarkable fluorescence on/off switching in the solid state. This may provide a promising way to construct high-contrast optical binary memory storage devices. (Z)-CN-MBE is virtually nonfluorescent but exhibits an extraordinary Z to E isomerization upon external light/thermal stimuli even in the solid state with a concomitant drastic fluorescence enhancement owing to unique aggregation-induced enhanced emission (AIEE) phenomenon of its trans isomer.