Optoelectronic properties and holographic optical recording of a novel unsymmetrical diarylethene

A unsymmetrical photochromic diarylethene, 1-[2-methyl-5-(4-methylphenyl)-3-thienyl]-2-(2-cyano-1, 5-dimethyl-4-pyrryl)hexafluorocyclopentene (10), was synthesized, and its optoelectronic properties were also investigated. The results showed that this compound had good thermal stability and exhibited reversible photochromism, changing from colorless to blue after irradiation with UV light both in solution and in PMMA amorphous film. The open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 429 nm in hexane solution (5 × 10^-5 mol/L) when excited at 330 nm and 415 nm in PMMA amorphous film when excited at 340 nm. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light and its closed-ring isomer showed almost no fluorescence. The electrochemical properties indicated that the oxidation onset and the Eg of the open-ring isomer were higher than those of the closed-ring isomer. Using diarylethene 1 as recording medium, polarization holographic optical recording was carried out successfully.