Synthesis and properties of tetraphenylethylene derivatived diarylethene with photochromism and aggregation-induced emission

A series of new diarylethene compounds with both photochromism and aggregation-induced emission have been synthesized by connecting tetraphenylethene and triphenylethene to the bisthienylethene. All the four compounds exhibit good photochromism upon irradiation with alternative UV and visible light. And they are all provided with aggregation-induced emission properties in tetrahydrofuran solution with different fraction of water, non-emissive in the pure tetrahydrofuran solution but yellowish green fluorescence in the aggregate or solid state. Furthermore, the compounds connecting tetraphenylethene to the bisthienylethene were found to exhibit the stronger fluorescence emission in the aggregate or solid state than the ones connecting triphenylethene to the bisthienylethene.