“…Photochromic diarylethenes undergo reversible photoinduced cyclization and cycloreversion reactions between two isomers upon irradiation with UV/visible light. Among various types of photochromic compounds, such as, spirobenzopyrans, azobenzenes, diarylethenes and fulgides, diarylethene derivatives with heterocyclic aryl rings are the most promising organic photochromic compounds because of the excellent thermal stability of two isomers, fatigue resistant character, rapid response and high reactivity in solid state, which could be potentially used for application to optical memory media [5][6][7], switching devices [8], display materials [9,10], photomechanical actuators [11,12], and so on. These properties enable diarylethene to have the most applicable potential for future high-density optical storage [13].…”