Papers by Keyword: 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: Graphene oxide (GO) was prepared via ultrasonic assisted chemical oxidation method. Contrasting with modified hummers method, GO prepared by ultrasonic assisted chemical oxidation method showed thinner flakes, the interlayer spacing increases. The emission spectra of the GO showed a similar excitation-dependent feature with the strongest peak (552 nm) excited at 477 nm.

Abstract: The picture collected by CCD camera usually takes surface interference informations, such as pollution and surface reflection.etc, in the meantime because of being subjected to light source and CCD camera oneself intelligent degree the influence of etc. factor, the ineluctability exists some yawp voices in the picture.For the sake of convex leak parts of pictures now, have to clean yawp voice and interference information, reserve true leakiness trace. This paper filters a processing, edge to withdraw towards identifying according to the calculator fluorescence picture of picture, and picture ash degree two values turned the selection method and fluorescence signal calculation method of threshold value to carry on a study.To fluorescence oil liquid seep into the examination carried on an experiment research, the realization seeped into the quantity of quantity to turn a calculation, to seep into the quantity carry on a precision examination, and carried on analysis as a result to the test.

Abstract: The recognition and sensing of biologically and environmentally important species has emerged as a significant goal in the field of chemical sensors in recent years¹. Fluorogenic methods in conjunction with suitable probes are preferable approaches for the measurement of these analytes because fluorimetry is rapidly performed, is nondestructive, is highly sensitive, is suitable for high-throughput screening applications^2,3. We synthesized rhodamine derivatives compounds by a Schiff base reaction.