Papers by Keyword: Photochromism

Abstract: A new symmetrical photochromic diarylethene, 1,2-bis-[2-methyl-5-(9,9-dibutyl-9H-fluorene) -3-thienyl] perfluorocyclopentene (1a), was synthesized and its optoelectronic properties, such as photochromism in solution and fluorescence were investigated. 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. The new diarylethene also exhibited relatively strong fluorescence by photoirradiation in solution and the fluorescence intensity decreased along with the photochromism upon irradiation 297 nm light and its closed-ring isomer showed almost no fluorescence.

Abstract: A photochromic diarylethene of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylamine)-3-thienyl)) perfluorocyclopentene was synthesized and characterized. Upon irradiation with UV light with the extended response time, the diarylethene underwent a ring opening reaction to produce opened forms and color change both in solution and in a PMMA amorphous film. Its properties, including photochromic behavior and fluorescent properties have been investigated. The results showed the compound exhibited good photochromism in acetonitrile solution and in PMMA amorphous film.

Abstract: A novel unsymmetrical diarylethene derivative bearing both phenyl and thiophene moieties, in which two chlorine groups were separately substituted at thiophene and the para-positions of the terminal phenyl ring, were synthesized. Its photochemical , fluorescence properties were investigated systematically both in solution and PMMA amorphous film. The results showed that this compound exhibited reversible photochromism, changing from colorless to purple after irradiation with 313 UV light both in solution and in PMMA amorphous film. Also, it exhibited remarkable fluorescence switching in the solid state.

Abstract: A novel isomeric photochromic diarylethene, 1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-pentylphenyl)-3-thienyl] perfluorocyclopentene, was designed and synthesized. Its fluorescent and photochromic properties were also studied in detail. The compound exhibited excellent photochromism, changing from colorless to bule after irradiation with UV light both in solution and in PMMA film. In addition, the fluorescence intensity of the photochromic diarylethene 1a declined remarkably, when irradiation with UV light.

Abstract: A new unsymmetrical photochromic diarylethene compound, 1-(2-methyl-3-benzothienyl)-2-(2-methyl-(5-ethynyl) trimethylsilane-3-thienyl) perfluorocyclopentene (1o) has been synthesized, and its optoelectronic properties, such as photochromism and the fluorescence spectra of diarylethene 1o in hexane solution was investigated. The results showed that this compound exhibited reversible photochromism in solution. The maxima absorption of compound closed-ring isomer 1c are 538 nm. 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 novel photochromic diarylethene bearing a pyrimidine moiety, 1-(2,4-dimethoxyl-5-pyrimidinyl)-2-[2-methyl-5-(9-phenanthrene)-3-thienyl] perfluorocyclopentene has been synthesized. Its properties, including photochromic behavior and fluorescent properties, have been investigated. The compound exhibited remarkable photochromism, changing from colorless to red after irradiation with UV light in solution. The fluorescence had a remarkable initial increase with subsequent dramatic decrease with increasing concentration. The results indicated that the pyrimidine moiety played a very important role during the process of photoisomerization reactions.

Abstract: An asymmetrical photochromic diarylethene 1-(3,5-Dimethyl-4-isoxazolyl)-2-[2-methyl-5-(p-ethoxyphenyl)-3-thienyl] perfluorocyclopentene (1o) was synthesized and its photochromic properties were investigated. Upon irradiation with 297 nm UV light, 1o exhibited 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 photochromic diarylethene having a pyrrole unit, which is named 1-(2-cyano-1,5-dimethyl-4-pyrryl)-2-{2-methyl-[5-(4-methylene-bromine) phenyl]-3-thienyl} perfluorocyclopentene, was designed and constructed successfully. And its properties have been discussed systematically, including photochromic, fluorescence switch and kinetics experiments in acetonitrile solution. The results showed that its photochromic behaviors could be modulated by UV/Vis light, changing from colorless to blue in acetonitrile solution. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction.

Abstract: A new class of unsymmetrical photochromic diarylethene bearing an isoxazole moiety was synthesized. Its photochemical properties, including photochromic behavior and kinetics, have been investigated systematically. The result indicated that the Diarylethene 1a changed the color from colorless to pink irradiation with 297 nm UV light, in which absorption maxima were observed at 522 nm in hexane. 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.

Abstract: A new photochromic diarylethene based on a phenanthrene, which is named 1-[2-methyl-5-(10-phenanthrenyl)-3-thienyl]-2-[2-methyl-5-(4-formylphenyl)-3-thienyl] perfluorocyclopentene, was designed and constructed successfully. At the same time, its photochromic properties, kinetics and fluorescence switch were investigated in detail. The results indicated that its photochromic behaviors could be modulated by UV/Vis light, changing from colorless to blue in dichloromethane solution. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. Furthermore, the optical switch experiment illustrated that the diarylethene 1o functioned as a remarkable fluorescent switch.