Property of a Novel Unsymmetrical Diarylethene Bearing a Benzothiophene for Optical Recording

A novel unsymmetrical photochromic diarylethene 1-[3-methyl-2-thienyl] -2[2-ethyl-3-benzothiophene] perfluoroyclopentene(1a) was synthesized, its photochromic, fluorescent, electrochemical and optical storage properties were investigated. The compounds exhibited remarkable photochromism both in solution and in PMMA film. In hexane, the open-ring isomer of the diarylethene 1a exhibited relatively strong and clear fluorescent switch when excited at 260 nm. The fluorescence intensity declined along with the photochromism upon irradiation with 297 nm light. The cyclization and cycloreversion quantum yields of 1 in hexane were determined too. The results showed that the eyelization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. This new photochromic system also exhibited remarkable optical storage character.