A Photochromic Diarylethene with a Six-Membered Aryl Unit for Polarization Optical Recording

A photochromic diarylethene bearing a six-membered aryl unit 1-((2-methyl-5-(3-chlorophenyl) -3-thienyl))-2-((2- methoxylphenyl))perfluorocyclopen- tene (1a) was synthesized and its photochromic and fluorescent properties were also investigated in detail. The results showed that this compound exhibited reversible photochromism, changing from colorless to blue after irradiation with UV light both in solution and in PMMA amorphous film. In hexane, compound 1a exhibited an absorption peak at 292 nm ,upon irradiation with 297 nm light, a new visible absorption band centered at 585 nm emerged while the original peak at 292 nm decreased. In PMMA amorphous film, diarylethene 1a also showed good photochromism as similar to that in solution .Upon irradiation with 313 nm light, the absorption maxima was observed at 583 nm. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light in PMMA amorphous film. In addition, polarization optical recording using diarylethene 1b as recording medium was carried out successfully.