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Photochromism and Optical Recording of a Novel Unsymmetrical Diarylethene Based on Pyrrole Ring

A new unsymmetrical photochromic diarylethene compound, 1-[(2-methyl-5-(4-aldehydephenyl)-3-thienyl)]-2-(5-cyano-1, 5-dimethyl-4-pyrryl) perfluorocyclopentene (1o), was synthesized and its photochromic behavior, kinetics properties optical storage properties were investigated in detail both in solution and PMMA amorphous film. The results showed that this compound had good thermal stability and exhibited pronounced reversible photochromism, changing from colorless to mediumpurple in solution whereas to mediumslateblue in PMMA amorphous film after irradiation with 297 nm UV light, which may be attributed to giving a bathochromic shift in PMMA amorphous film. The colorless open form with fluorescence character could be regenerated by irradiation with visible light. The cyano group and its substituted position can availably modulate the optical and electrochemical behaviours of these diarylethene derivatives. In addition, polarization optical recording using this diarylethene as recording medium was performed successfully.