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61.
The hydroacylation reaction of aldehydes with azodicarboxylates catalyzed by copper(II) acetate monohydrate has been reported. The reaction of various aldehydes gave the corresponding hydroacylation products in 60-98% yields under mild conditions. The method is simple, economical, and has practical advantages for the construction of the carbon-nitrogen bonds. 相似文献
62.
J. D. Shakos A. M. Cox D. P. West K. S. West F. A. Wade T. A. King R. D. Blackburn 《Optics Communications》1998,150(1-6):230-234
The processes limiting the rate of response of highly diffractive, reorientationally enhanced photorefractive polymer composite materials are identified from a series of degenerate four wave mixing and Mach–Zehnder interferometric measurements. In the regime of low intensity writing beams charge generation limits the rate of holographic grating formation, but at higher intensities charge transport or reorientation of dye molecules can restrict the rate of grating formation more strongly. A grating risetime of 540 ms is observed in a composite of high dye content with high reorientational mobility of the dye molecules. In this case it is proposed that the charge carrier mobility of the doped poly(N-vinylcarbazole):2,4,7-trinitro-9-fluorenone (PVK:TNF) matrix is the principal limiting factor in grating response rates. 相似文献
63.
Dye molecules containing two or more polymethine structural units, or at least one polymethine and one polyene structural unit, generally exhibit coupling effects that determine the spectroscopic behavior and other physicochemical properties of the substance. The coupling concept can be used inter alia to fit the quinone dyestuffs, the indigoids, and the indanthrenes into a general poymethine color system and to perdict new dye structures. 相似文献
64.
A new simple method has been used to prepare 6-substituted 4-(subst. amino)-5-aryldiazenyl-1-arylpyridazinium salts from N-methyl- or N-aryl-3-amino-1-phenylbut-2-en-1-ones and 4-aminopent-3-en-2-ones and substituted benzenediazonium tetrafluoroborates or hexafluorophosphates. The structure of selected derivatives was studied by means of 15N NMR spectra and X-ray. 相似文献
65.
P. R. Hammond A. N. Fletcher R. A. Henry R. L. Atkins 《Applied Physics A: Materials Science & Processing》1975,8(4):315-318
Two new families of lasing dyes, the 8-azacoumarins and the 8-azaquinolones are described and are found to operate blue-shifted
from the coumarins and quinolones. Like the quinolones, they have higher thresholds and lower slope efficiencies than the
coumarins. All have yielded long output pulses on long pulse excitation.
This study was supported under contract SANL 284 from the Lawrence Livermore Laboratory. 相似文献
66.
67.
Online LC-MS-MS process monitoring for optimization of biological treatment of wastewater containing azo dye concentrates 总被引:1,自引:0,他引:1
A biological high-performance treatment process comprising two 40-L reactor compartments has been developed for purification
and decoloration of concentrated textile wastewater containing up to 15 g L−1 reactive dyestuff. The decoloration rate of 95% meets the requirements of German legislation for textile wastewater treatment.
Successful process development and optimization was achieved by use of high-performance liquid chromatography, with diode-array
and electrospray tandem mass spectrometric (LC-ESI-MS-MS) detection, coupled with inline microfiltration membrane-sampling
devices, applied online to bioreactors as a process analytical tool for the first time. The optimum process performance was
found by correlation of dye and decoloration product-specific concentrations with summary properties such as redox potential
and dissolved oxygen content. Details of the degradation and decoloration mechanism for the azo dye reactive black 5 was revealed
by using mass spectrometry for structure elucidation. 相似文献
68.
Tangestaninejad S Moghadam M Mirkhani V Mohammadpoor-Baltork I Salavati H 《Ultrasonics sonochemistry》2008,15(5):815-822
Na5PV2Mo10O40 supported on nanoporous anatase TiO2 particles, TiO2–PVMo, was used as an efficient photocatalyst for photocatalytic degradation of different dyes by visible light using oxygen as oxidant. This catalyst showed a good catalytic activity in the sonocatalytic and sonophotocatalytic decomposition of different dyes in aqueous solutions. The TiO2–PVMo composite showed higher photocatalytic and sonocatalytic activity than pure polyoxometalate or pure TiO2. 相似文献
69.
K.S. Levchenko K.A. Chudov E.V. Zinoviev K.A. Lyssenko A.N. Fakhrutdinov D.U. Demin N.O. Poroshin P.S. Shmelin E.P. Grebennikov 《Tetrahedron letters》2019,60(23):1505-1508
A series of new chromophores based on 4-(dicyanomethylene)-2-vinyl 4H-chromenes was synthesized and their physical properties (UV–Vis, NMR, mass spectrometry) were studied. The chromophores show moderate or good solubility in organic solvents. Solvatochromism was investigated for compounds in solvents of low (1.4-dioxane, chlorobenzene, methylene chloride) and high polarity (acetone, acetonitrile). The calculations of the first hyperpolarizability (β) was performed using M052X/6-31+G(d) approximation. Chromophore’s molecules are characterized by high calculated values of the first hyperpolarizability (β) that is only 15% lower than that of FTC analogs. 相似文献
70.
Wenxin Lin Jianqiu Gong Huizhong Zhou Yijia Wang Linhui Gao Hongliang Zhu Jianjun Chen 《无机化学与普通化学杂志》2019,645(20):1215-1219
In this work, two types of chromophore i.e. the pyrromethene and perylene families dyes were doped into elastic polymeric host materials based on polydimethylsiloxane (PDMS), which had been widely employed in various applications. The solubilities, spectroscopic and laser properties of these dyes doped into PDMS matrices were systematically investigated. Tunable laser output with high conversion efficiencies and low laser thresholds were observed and calculated. The laser longevity of pyrromethene dyes doped in PDMS matrices could exceed 1 × 105 pulses through a fast self‐recovery on the laser output with the elapse of aging time. The efficient and stable laser output of the dopants and the flexibility of the PDMS host provided the feasibility of such gain media as mechanically tunable laser sources, which might be employed as cost‐effective components on integrated bio‐chips. 相似文献