Papers by Keyword: Photochromism

Abstract: A new fluorescent switch based on a photochromic diarylethene, 1-[2-methyl-5-(4-hydroxymethylphenyl)-3-thienyl]-2-[2-methyl-5-(4-azidomethylphenyl)-3-thienyl] perfluorocyclopentene has been synthesized, And its properties have been discussed systematically in acetonitrile solution and in PMMA, such as photochromic, fluorescence switch and kinetics experiments, and its optoelectronic properties, The results showed that this compound exhibited reversible photochromism and the maxima absorption of compound closed-ring isomer 1c is 590 nm. Its fluorescence intensity decreased along with the photochromism from open-ring isomers to closed-ring isomers.

Abstract: A novel asymmetrical photochromic diarylethene 1-(2-methyl-3-benzothienyl)-2-[2-methyl-5-(3-trifluoromethyl)-3-thienyl] perfluorocyclopentene was synthesized and its photochromic and fluorescent properties were also investigated. The compound exhibited remarkable photochromism, changing from colorless to red after irradiation with UV light and the open-ring isomer of the diarylethene 1 exhibited relatively remarkable fluorescence in hexane solution. The cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction.

Abstract: A novel unsymmetrical photochromic diarylethene compound 1-(2-methyl-3-benzothienyl)-2-[3-methyl-2-thienyl] perfluorocyclopentene was designed and constructed successfully. Its optoelectronic properties have been discussed systematically, such as photochromic, fluorescence switch, kinetics experiments in hexane solution and PMMA. The consequences showed that this compound exhibited good reversible photochromism. The maxima absorption of compound closed-ring isomer 1c is 468nm. Upon irradiation with 297nm UV light, Its fluorescence intensity decreased along with the photochromism from open-ring isomers to closed-ring isomers upon irradiation with 297 nm UV light.

Abstract: A new unsymmetrical photochromic diarylethene 1-[(2-methyl-3-benzothiophene)]-2-[2-methyl-5-(1,3-dioxolane)-3-thienyl] perfluorocyclopentene (1o) has been synthesized. In the meantime, its photochromic, kinetics and fluorescence properties were investigated in detail. The results showed this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in solution [1]. The two isomers differ from each other not only in their absorption spectras, but also in many changes of various physical and chemical properties, such as dielectric constant, refractive index, as well as oxidation/reduction potential, etc [2]. Diarylethene 1 changed the color from colorless to pink upon irradiation with 297 nm UV light, in which absorption maxima were observed at 516 nm in acetonitrile.

Abstract: A new unsymmetrical photochromic diarylethene 1-(2,5-dimethyl-3-thiazolyl)-2-[2-methyl-5-phenyl-(4-vinyl)-3-thiophene] perfluorocyclopentene (1o) was designed and constructed successfully. And its photochromic reactivity, HPLC, kinetics were also investigated systematically. Upon alternating irradiation with UV and visible light in solution, this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions. Diarylethene 1 changed the color from colorless to orange, in which absorption maxima were observed at 596 nm in acetonitrile. What is more, the photoconversion ratio of 1 is 37%.

Abstract: A novel photochromic diarylethene was synthesized and its photochromic and fluorescent properties were investigated. The results showed that this compound exhibited reversible photochromism, changing from colorless to amaranth after irradiation with UV light both in solution and PMMA amorphous film. In hexane, compound 1a exhibited an absorption peak at 266 nm, upon irradiation with 297 nm light, a new visible absorption band centered at 530 nm emerged while the original peak at 266 nm decreased. In PMMA amorphous film, diarylethene 1a also showed good photochromism as similar to that in solution. The photochromic reaction kinetics indicated that the cyclization processes of 1a belong to the zeroth order reaction and the cycloreversion process belong to the first order reaction. Diarylethene 1a also exhibited good fluorescent switching both in solution and in PMMA film upon alternating irradiation with UV and visible light.

Abstract: A new photochromic diarylethene of 1-(3,5-dimethyl-4-isoxazole)-2- (2-methyl-(5-ethynyl)-3-thienyl) perfluorocyclopentene (1o) was synthesized. Its photochromic and fluorescence properties were investigated systematically. Upon irradiation with UV light with the extended response time, the diarylethene underwent a ring opening reaction to produce closed forms and color change in solution. The results showed the compound exhibited good photochromism in hexane solution. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. Moreover, diarylethene 1o also exhibited obviously fluorescence switches along with the photochromism.

Abstract: A new unsymmetrical photochromic diarylethene 1-(2-methyl-5-phenyl-3-thiophene)-2-[2-methyl-5-phenyl-(4-vinyl)-3-thiophene] perfluorocyclopentene (1o) has been synthesized, and its photochromic reactivity, fluorescent were also investigated. The results showed this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in solution,Diarylethene 1 changed the color from colorless to blue upon irradiation with 297 nm UV light, in which absorption maxima were observed at 596 nm in acetonitrile.

Abstract: An unsymmetrical photochromic diarylethene which called 1-[2-methyl-5-(3-cyanophenyl)-3-thienyl]-2-[2-methyl-5-(4-pentylphenyl)-3-thienyl] perfluorocyclopentene (1a) was synthesized and its properties such as photochromism and fluorescence were investigated in detail. The results showed that this compound undergo reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in both solution and a PMMA film.

Abstract: A photochromic diarylethene of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylazide)-3-thienyl)) perfluorocyclopentene was synthesized and its properties such as photochromism and fluorescence in solution were investigated in detail. The diarylethene has shown good photochromic behavior in solution with alternating irradiation by UV/vis light. Its fluorescence intensity decreased along with the photochromism from open-ring isomers to closed-ring isomers upon irradiation with 297 nm UV light.