Cong Bin Fan

Photochromic Fluorescence Switching Diarylethene Flanking a Methoxy Group

Fluorescent photoswitching molecule in which photochromic diarylethene with six-number phenyl unit and thiophene ring attached a phenyl methoxy group was synthesized. The compound exhibited pronounced photochromic and synchronous fluorescence switching properties. Irradiation of the open form of compound with UV light resulted in immediate photocyclization to the blue closed form with nonfluorescence; the colorless open form with fluorescence character could be regenerated by irradiation with visible light. In terms of potential use for optical storage and readout, this compound displays fluorescence discrimination between its open and closed form. This fluorescence switching could be the basis of a remote control nondestructive readout method.

Synthesis and Properties of a Photochromic Switch

A new purple photochromic diarylethene compound, [1- (2-ethyl-3-benzothienyl)-2-(1,3,5-trimethyl-4-pyrazolyl)]perfluoroclopentene (1a), was synthesized and its photochemical properties were investigated in detail. The results demonstrated that the compound has good photochromism in PMMA amorphous film and fluorescence switching properties.

Photochromism and Optical Recording of a Novel Diarylethene Bearing Phenanthrene Unit

Photochromic molecules are part of a large class of materials in which light stimulus not only induces a color variation but also affects other physicochemical properties. In the paper, an asymmetrical photochromic diarylethene, 1-(2,4-dimethyl-3-thiazole)-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyPerfluorocyclopentene was synthesized and its photochromic and fluorescent properties were systematically investigated. The compound exhibited remarkable photochromic, changing from colorless to OrangeRed after irradiation with UV light both in solution and in PMMA film. In addition, its fluorescence property was also discussed. When irradiation with UV light, the fluorescence intensity declined remarkably. The results showed that the diarylethene exhibited a relatively strong fluorescence switch along with the photochromism from open-ring isomer to closed-ring isomer. Using this diarylethene 1a as optical storage was performed successfully.

Photochromism and Fluorescent Switch Material of a Novel Diarylethene Bearing Phenanthrene Unit

A novel photochromic diarylethene, 1-(2,5-dimethyl-thienyl)-2-[2-methyl-5-(10-phen-anthrenyl)-3-thienyPerfluorocyclopentene was designed and synthesized, and its photochromic and fluorescent properties were also investigated in detail. The compound exhibited remarkable photochromism, changing from colorless to violet after irradiation with UV light both in solution and in PMMA film. The fluorescence intensity declined remarkably, when irradiation with UV light. Using this diarylethene 1o as optical storage was performed successfully.

Synthesis and Properties of a Novel Unsymmetrical Diarylethene with a Benzothiophene and a Thiazole Group

A new unsymmetrical photochromic diarylethene 1o, which is named 1-(2-methyl-benzothiophene)-2-(2,4-dimethyl-5-thiazoly) perfluorocyclopentene, was synthesized. In the meantime, its photochromic, kinetics and fluorescence properties were investigated in detail. The result indicated that this diarylethene had good thermal stability and exhibited reversible photochromism, changing the color from colorless to orange in hexane solution upon appropriate irradiation with 297 nm UV light, respectively. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with UV light in hexane solution. In addition, the results demonstrated that the unsymmetrical diarylethene compound 1o, which we have synthesized, had attractive properties for potential application in optical storage.

Study on Photochromic Properties of 1-(2-methoxyphenyl)-2-[2-methyl-5-(1,3-dioxolane)-3-thienyl]perfluorocyclopentene

A new unsymmetrical photochromic diarylethene 1o, which is named 1-(2- methoxyphenyl)-2-[2-methyl-5-(1,3-dioxolane)-3-thienyl]perfluorocyclopentene, was synthesized. Its photochromic and simulated molecule structure were also investigated in detail. This diarylethene underwent reversible photochromism, changing between colorless and blue in hexane solution upon appropriate irradiation with UV/vis light. The kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. In addition, this compound can be used as optical recording materials.

Synthesis and Properties of a New Unsymmetrical Diarylethene Bearing Benzothiophene and Thiophene Rings

A new unsymmetrical isomeric diarylethene was synthesized, namely1-[2-methyl-(5-(4-hydroxyl) phenyl) -3-thieny-2-(2-methyl-3-benzothiophene) perfluorocyclopentene (1o). Its photochromic reactivity both in solution and in PMMA film, photoconversion ratio at photostationary state, and fluorescence were investigated in detail. The compound displayed excellent photochromism both in solution and in PMMA film. The isomeric compound also functioned as a fluorescence switch and concentration dependence on the fluorescence spectrum in hexane.

A Novel Unsymmetrical Diarylethene Material Bearing Double Thiophene Ring

A new photochromic diarylethene compound, 1-[2-methyl-5-(3-thienyl)-3-thieny-2-[2-methyl-5-(3-benzaldehyde)-3-thieny perfluorocyclopentene (1a) was synthesized. Its properties, including photochromism and fluorescence were investigated in detail both in solution and PMMA amorphous film. It underwent reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in hexane. The compound showed good phtochromism both in solution and in solid states. Diarylethene 1a changed the color from colorless to navy upon irradiation with 297 nm UV light, in which absorption maxima were observed at 577 nm in hexane and at 592 nm in PMMA film, respectively. Using diarylethene 1b/PMMA film as recording medium, optical recording was performed successfully.

Synthesis, Properties of a Photochromic Diarylethene Material Bearing Benzofuran and Thiazole Rings

A new photochromic diarylethene compound, 1-(2-methylbenzofuran)-2-[(2,4-dimethyl-5-thiazolyl] perfluorocyclopentene (1o), was synthesized, and its photochromic reactivity, fluorescent were also investigated. The results showed that this compound exhibited reversible photochromism, changing from colorless to yellow after irradiation with UV light both in solution and in PMMA amorphous film. In hexane solution, the openring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 410 nm when excited at 307 nm.

Photoinduced Fluorescence Switching of a New Diarylethene and its Application in Optical Recording Storage

A novel unsymmetrical photochromic diarylethene 1-(2-methyl-3-benzothienyl)-2-{2-n-butyl-5-[2-(1,3-dioxolane)]-3-thienyl}perfluorocyclopentene(1O) was synthesized, and its photochromic, fluorescent and optical strorage properties were investigated. The compounds 1O exhibited remarkable photochromism both in solution and in PMMA film, and the results showed that the cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. In addition, this new photochromic system also exhibited remarkable optical storage character.