A New Class of Diarylethene Compounds that Exhibit Turn‐On Emission: From Aggregation‐Induced Emission to Anti‐Kasha Emission

Abstract Diarylethenes (DAE) are a well‐known class of photochromic compounds with diverse applications ranging from optoelectronic devices to biological sensors. DAEs exhibiting emission in the closed form show potential for super‐resolution imaging, however, these are rare because DAEs in the closed form are notorious fluorescence quenchers. Here a series of DAE compounds containing phosphine oxide groups is reported that exhibit turn‐on emission and are the first examples of DAEs showing both aggregation‐induced emission (AIE) and anti‐Kasha emission in the closed form. The molecular design of the DAEs originates from careful selection of diphenylphosphine oxide groups, which have the appropriate bulkiness and electron‐withdrawing ability. Furthermore, the emission wavelength can be tuned by substituents, leading to a new class of diarylethenes that hold promise for applications including super‐resolution imaging.