Synthesis and Properties of a Novel Unsymmetrical Diarylethene with Thiophene and Benzene Unit

A novel photochromic diarylethene with thiophene and benzene compound, 1-{[2-methyl-5-(formyl)-3-thienyl]}-2-(2-methylphenyl)perfluorocyclopentene (1a) has been synthesized for the examination of its properties including photochromism, fluorescence properties and optical recording. Diarylethene 1a changed the color from colorless to purple upon irradiation with 297 nm UV light, in which absorption maxima were observed at 566 nm in hexane and at 577 nm in PMMA film, respectively. The open-ring isomer of the diarylethene 1 exhibited good fluorescence switch in hexane solution. In hexane solution, the open-ring isomer of the diarylethene 1a exhibited relatively fluorescence at 376 nm when excited at 326 nm.