Synthesis, crystal structure and its optical and electrochemical properties of a new unsymmetrical diarylethene

A new unsymmetrical photochromic diarylethene, 1-(2-methyl-5-phenyl-3-thienyl),2-(2-methyl-5-(3-methylphenyl)-3-thienyl)-3,3,4,4,5,5-hexafluorocyclopent-1-ene (MPMTH), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. Its optical and electrochemical properties, including photochromic reactivity both in solution and in the crystalline phase, fluorescence and electrochemical property were investigated. The diarylethene underwent reversible photochromism, changing from colorless to blue after irradiation with UV light or visible light. The maximum absorption of the closed-ring isomer of MPMTH was observed at 577 nm in hexane. In hexane, the open-ring isomer of MPMTH exhibited relatively strong fluorescence at 310 nm when excited at 280 nm. The irreversible anodic oxidation of MPMTH was observed by performing linear sweep experiment.