Photochromism of novel isomeric diarylethenes with benzofuran and pyridine moieties

•Three new isomeric diarylethenes with a pyridine moiety were synthesized.•They exhibited favorable photochromism, acidchromism, and functioned as photoswitches.•The nitrogen atom position in pyridine played an vital role in photoisomerization.

A new class of isomeric diarylethenes with benzofuran and pyridine moieties was synthesized to investigate the effects of the position of the nitrogen atom in pyridine moiety on their photochromism, acidichromism, and fluorescence. The six-membered pyridine moiety was connected directly to the central cyclopentene ring as an aryl moiety and participated in the photoisomerization reaction in both solution and solid media. These isomeric diarylethenes exhibited multi-addressable switching behavior by the stimulation of acid/base and light. Addition of trifluoroacetic acid to the solutions of these compounds produced the corresponding protonated derivatives. The protonated derivatives exhibited excellent photochromism and notable acidichromism, and the different nitrogen atom position resulted in distinguishable absorption spectra and color changes. The results revealed that the effects of the nitrogen atom position in pyridine moiety played a very important role during the photoisomerization process of these isomeric diarylethenes.

Graphical abstractA new class of isomeric diarylethenes with benzofuran and pyridine moieties was synthesized to investigate the effects of the nitrogen atom position in pyridine moiety on their photochromism, acidichromism, and fluorescence. The results revealed that the effects of the nitrogen atom position in pyridine moiety played a very important role during the photoisomerization process of these isomeric diarylethenes.Figure optionsDownload full-size imageDownload as PowerPoint slide