Advanced Materials Research Vol. 830

Abstract: A novel photochromic diarylethene with a six-membered pyrimidine was synthesized to investigate its photochromic behaviors. The compound showed favorable photochromism and functioned as notable fluorescent photo-switches in both solution and PMMA film. The results indicated that the pyrimidine moiety played a very important role during the process of photochromic reaction for the diarylethene derivative. Using this diarylethene 1c as optical storage was performed successfully.

Abstract: A new photochromic diarylethene, 1-(2-cyano-1,5-dimethyl-4-pyrryl)-2-[2-methyl-5-(10-phen-anthrenyl)-3-thienyperfluorocyclopentene was synthesized and its photochromic and fluorescent properties were also systematically investigated. The results showed that this compound exhibited reversible photochromic, changing from colorless to blue after irradiation with UV light in both solution and PMMA amorphous film. The fluorescence intensity declined along with the photochromic when irradiation with UV light. However the fluorescence switch in PMMA amorphous film showed more remarkable than in solution.

Abstract: A new photochromic diarylethene compound 1-[(2-methyl-5-(4-trifluoromethyphenyl)-3-thienyl)]-2-{2-methyl-5-[2-(1,3-dioxolane)]-3-thienyl} perfluorocyclopentene 1O was synthesized. Its optoelectronic properties, such as photochromism in solution as well as in poly-methylmethacrylate (PMMA) amorphous films, fluorescences switch were investigated in detail. Upon irradiated UV light it changes from colorless to purple in solution and PMMA amorphous film, respectively. Finally, the diarylethene 1O was exhibited remarkable fluorescence switch properties along with the cyclization reactions. When the concentration arrived at 1 × 10^-5 mol L^-1, the fluorescence peak had the maximum.

Abstract: A new unsymmetrical isomeric photochromic diarylethene, 1-[2-methyl-3-naphthalen-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyperfluorocyclopentene, was designed and synthesized. Its photochromic and fluorescent properties were also investigated in detail. The compound exhibited excellent photochromism, changing from colorless to red after irradiation with UV light both in solution and in PMMA film. Furthermore, the fluorescence intensity of the photochromic diarylethene 1a declined remarkably, when irradiation with UV light.

Abstract: A novel unsymmetrical photochromic diarylethene, 1-(2-methyl-5-chlor-ine-3-thienyl)-2-(2-ethyl-benzofuran-3-yl) perfluorocyclopentene (1a), was synthesized and its photochromism and photo-induced anisotropy was investigated. Specifically, photochromism in solution and in PMMA amorphous films were studied. The diarylethene showed exhibited reversible photochromism, changing from colorless to red after irradiation with UV light both in solution and in PMMA amorphous film. This new photochromic system also exhibited remarkable optical storage character.

Abstract: A new photochromic diarylethene compound 1-(2-cyan-3-phenyl)-2-[5-(4-cyanobenzene) -2-methyl-3-thienyl] perfluorocyclopentene was synthesized. And their properties inculding photochromis, fluorescence in both hexane and solid films, reaction kinetics of cyclization and cycloreversion were studied. And its absorption maxima were observed at 539 nm in hexane and at 552 nm in PMMA films, respectively, upon irradiation with 313 nm UV light. The fluorescence intensity of diarylethene decreased upon irradiation with 313 nm UV light. Besides, the cyclization and cycloreversion processes of the compound were determined to be the zeroth and first order reaction by UV-Vis spectra, respectively.

Abstract: A new unsymmetrical photochromic diarylethene compound 1-[(2-methyl-5-(2-pyridyl)-3-thienyl)]-2-{2-methyl-5-[2-(1,3-dioxolane)]-3-thienyl} perfluorocyclopentene 1O was synthesized. The optoelectronic properties, including photochromism, fluorescences switch and optical recording were investigated in both solution and a PMMA amorphous film. This compound exhibited good photochromism, changing from colorless to purple after irradiation with 297 nm UV light. The new diarylethene also showed remarkable fluorescence switches by photoirradiation in hexane solution. Finally, photo-mode rewritable optical storage using 1C was carried out successfully.

Abstract: An unsymmetrical diarylethene derivative bearing both phenyl and thiophene moieties, in which a cyano group was substituted at the ortho-position of the phenyl ring and a chlorine elements was substituted at the five-position of the thiophene ring, was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in solution , and its absorption maxima were observed at 501 nm in hexane. The fluorescence intensity of diarylethene decreased along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 254 nm UV light in hexane.

Abstract: A novel photochromic diarylethene based on thiophene and a six-membered aryl moieties 1-(2-methyl-5-chloro-3-thienyl)-2-(2-trifluoromethylphenyl) perfluorocyclopentene has been synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in PMMA film. The fluorescence intensity of diarylethene decreased along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 254 nm UV light in PMMA. The fluorescence intensity decreases along with the increase of solution concentration.

Abstract: A new unsymmetrical photochromic diarylethene 1a was synthesized and its photochromism were investigated. The compound exhibited good photochromism in solution with alternating irradiation by UV/Vis light, and the maxima absorption of its closed-ring isomer is 542 nm. The open-ring isomer exhibited relatively strong fluorescence at 420 nm. Its fluorescence intensity decreased along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with UV light.