Synthesis And Photochromic Properties Of Imidazole-based Diarylethenes

Property-switchable compounds such as photo response materials were often used in the optoelectronic materials and biology science due to their sensitive response time and simple operation. Therefore a large number of photochromic compounds with various photoresponsive units were synthesized and their properties were investigated in the past decade. Among various photochromic systems, these diarylethene derivatives containing two thiophene rings have been widely applied in the optical memories and photoswitches.Herein, we introduced the imidazole into the diarylethene, and synthesized a series of photochromic compounds and their photochromic properties were investigated. The detailed contents are depicted as follows:1. A series of symmetrical imidazole-and N-methylated imidazole-based diarylethenes were synthesized, and the structures have been well characterized by elemental analysis,1H NMR, 13C NMR, and mass spectrometry.2. Their photochromism were investigated upon UV/vis light irradiation in DMF (2.0×10-5 mol/L) solution. The significant red-shift of UV absorption was observed after irradiation with UV light when the substituents on the benzene ring (such as methoxyl group) were introduced. But N-methylation on the two imidazole rings will result in a blue-shift of UV absorption. The photophysical properties can be adjusted by changing the substituents, which provides a new strategy for the design of diarylethenes with excellent properties.