Synthesis and Fluorescence Switching of a New Unsymmetrical Diarylethene Bearing a Pyridine Ring

A new unsymmetrical photochromic diarylethene, 1-(2-methylpyridine)-2-[2-methyl-5-(3-cyanophenyl)-3-thienyl]perfluorocyclopentene(1a)was synthesized and its photochromic and fluorescent properties were investigated. It underwent reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film, and the Diarylethene 1a changed the color from colorless to violet in PMMA film and to magenta in solution upon irradiation with UV light .This new photochromic system also exhibited remarkable fluorescence intensity and clear fluorescent switches by photoirradiation both in solution and in PMMA film. And rewritable holographic optical storage using 1a was performed. At last, optical recording using diarylethene 1b as recording medium was carried out successfully.