Papers by Keyword: Fluorescence

Abstract: An unsymmetrical photochromic diarylethene compound, 1-(2-methyl-3-benzofuranyl)-2-[2-methyl-5-(4-cyanophenyl)-3-thienyperfluorocyclopentene was synthesized, and its photochromic properties, kinetics of the photochromic cyclization/cycloreversion and fluorescence were investigated in detail. The compound exhibited good photochromism, changing from colorless to red after irradiation with 297 nm UV light, in which absorption maxima were observed at 530 nm in hexane solution. Simultaneously, cyclization/cycloreversion kinetics of this diarylethene was researched. The open-ring isomer of the diarylethene exhibited relatively strong fluorescence at 377 nm in hexane solution (2 × 10^-5 mol L^-1), when excited at 327 nm. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light. The fluorescence spectra of the diarylethene are depended on the concentration.

Abstract: The photochchromic diarylethene was synthesized and explored, which is named 1-(2,4-dimethoxyl-5-pyrimidinyl)-2-[2-methyl-5-(2-trifluoromethylphenyl)-3-thienyperfluorocyclopentene. This compound has shown good photochromic behavior. When irradiated with UV light. The compound changed from colorless to violet, which showed a relatively strong fluorescence switch along with the photochromism from open-ring isomer to closed-ring isomer.

Abstract: A novel photochromic diarylethene bearing a six-membered pyrimidine as one aryl moiety was synthesized to investigate its photochromic behaviors. The diarylethene exhibited good photochromism and functioned as a fluorescence switch both in hexane and in PMMA film. The fluorescence had a remarkable initial increase with subsequent dramatic decrease with increasing concentration. The results suggested that the pyrimidine moiety played a vital role during the process of photoisomerization reaction for the diarylethene.

Abstract: An asymmetrical photochromic diarylethene 1-[2,5-dimethyl-3-thieny-2-[2-methyl-5-(p-N,N-dimethylaminophenyl)-3-thienyperfluorocyclopentene was synthesized and its photochemical properties were investigated in detail. The results demonstrated that the compound has excellent photochromic properties and good fluoresence. The cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. The fluorescence intensity increased with increasing concentration, but when the concentration increased enough high, the fluorescence intensity decreased rapidly.

Abstract: A novel unsymmetrical photochromic diarylethene 1o, which is named [1-(2-Methyl-5-pheyl-3-thienyl)-2-(2-methyl-5-(4-cyanophenyl)-3-thienyperfluorocyclopentene, was synthesized and its structure authenticated. What is more, photochromic, kinetics and fluorescence properties of the diarylethene were investigated in detail. The result indicated that this diarylethene photochromism could be controlled by UV-Vis light, changing the color from colorless to blue in hexane solution upon appropriate irradiation with 297 nm light, respectively. Its In the meantime, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. In addition, the fluorescence intensity of diarylethene decreased dramatically from open-ring isomer to closed-ring isomer. The fluorescence switching property can be potential use for optical data storage.

Abstract: A new unsymmetrical photochromic diarylethene compound, namely 1-[2-methyl-5-(4-methoxyphenyl)-3-thieny-2-[2-methyl-5-(3-methoxy-4-formyphenyl)-3-thieny perfluorocyclopentene, was synthesized and its properties were investigated in detail, including photochromic reactivity kinetics and concentration effect. The results showed that the compound exhibited remarkable photochromism, changing between colorless and blue in solution, respectively. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction.

Abstract: The synthesis and nonlinear optical properties of two N, N-dimethylaminophenyl substituted BOPIMs, BOPIM-ma and BOPIM-dma, were investigated. A more significant solvatochromic shift is achieved in BOPIM-ma, which is more sensitive to solven. It is distinct that the energy gap between the HOMO and LUMO for BOPIM-ma, 2.503 ev, is larger than that of BOIM-dma, 2.449 ev, an indication of the functionalization of N,N-dimethylaminophenyl group.

Abstract: A new photoinduced fluorescent switch based on a photochromic diarylethene, 1-(2-methyl-3-benzothiophenyl)-2-[2-methyl-5-(4-azidomethylphenyl)-3-thienyperfluorocyclope-ntene was synthesized and its photochromism was investigated. The results showed that this compound exhibited reversible photochromism, changing from colorless to purple upon irradiation with UV light both in solution and in PMMA amorphous film. In acetonitrile, the open-ring isomer of the diarylethene 1o exhibited relatively strong fluorescence at 473 nm when excited at 320 nm. The results demonstrated that the diarylethene can be also functioned as a fluorescence switch.

Abstract: An unsymmetrical photochromic diarylethene 1-(2-trifluoromethylphenyl)-2-[2-methyl-5-(3-N,N-dimethylphenyl)-3-thienyperfluorocyclopentene (1a) was synthesized and its photochromism, fluorescent properties and reaction kinetics of cyclization and cycloreversion were studied in detail. The compound exhibited remarkable photochromism and its absorption maxima were observed at 552 nm in hexane and at 569 nm in PMMA films upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased upon irradiation with 297 nm UV light. In addiation, reaction kinetics of 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 isomeric photochromic diarylethene, 1-[2-methyl-3-benzene]-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 orchid 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. Using this diarylethene 1a as optical storage and fluorescence switches was performed successfully.