Multifunctional phenanthrene-bridged dithienylethenes and their isomers: Preparation, separation and performances

Abstract

In this article, photoswitchable phenanthrene-bridged dithienylethenes bearing different functional groups have been designed and synthesized. Their parallel and antiparallel isomers with different performances have been conveniently separated and purified by common silica-gel column chromatography, which is desirable for practical application. The significant photochromism and controllable fluorescence have been investigated in solid, solution and PMMA film. Further research results showed that the modified dithienylethenes could overcome the irreversibility of the unmodified dithienylethene and exhibited significant photoswitchable aggregation-induced emission (AIE). Moreover, the fluorescence of the target molecules bonded phenolphthaleins and phenols can be independently and reversibly regulated by both acid-base and UV–Vis light, respectively. This research provides a new selection for the reversible multi-responsive and multifunctional fluorescent molecular switches.