Synthesis, Properties and Application in Optical Memory of a Photochromic Diarylethene Bearing Chlorine Atoms

Abstract

A new unsymmetrical photochromic diarylethene compound, 1-(2,4-dimethyl-5-thiazolyl)-2-[5-(2-chlorobenzene)-2-methyl-3-thienyl]perfluorocyclopentene(1a), was synthesized and its photochromism and photo-induced anisotropy was investigated. Diarylethene 1a changed the color from colorless to Orange-red upon irradiation with 297 nm UV light, in which absorption maxima were observed at 479 nm in hexane and at 485 nm in PMMA amorphous film, respectively. It also showed good photochromism and functioned as an effective fluorescent photoswitch in solution. In hexane, the open-ring isomer of the diarylethene 1a exhibited relatively strong fluorescence at 428 nm when excited at 315 nm. This new photochromic system also exhibited remarkable optical storage character.