Synthesis and Properties of 1-2-trifluoromethylphenyl-2-2-methyl-5-(3,5-difluorophenyl)-3-thienyl perfluorocyclopentene

摘要

An asymmetrical photochromic diarylethene 1-[2-trifluoromethylphenyl]-2-[2-methyl-5-(3,5-difluorophenyl)-3-thienyl]perfluorocyclopentene (1o) was synthesized and its phtochromic, fluorescent properties in both solution and PMMA films were investigated in detail. This compound exhibited remarkable photochromism, upon irradiation with 297 nm UV light, the colorless solution of 1o turned to plum with a new visible absorption band centered at 544 nm (ε =3.75 × 10~3 L mol~(-1) cm~(-1)) attributable to the closed-ring isomer 1c. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer in PMMA films and in hexane. The emission intensity of diarylethene 1o in a photostationary state was quenched to ca. 64% in hexane and 27% in PMMA films.