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1.
Abstract Three groups of dyes were synthesized and characterized in order to examine their solubility, absorption spectrum, and order parameter in liquid crystal hosts. Our synthesis method allowed the formation of the diazonium salts and the diazo coupling in ethyl acetate instead of an aqueous medium, permitting the formation of long and neutral azo dyes. In the liquid crystal BDH-E7, they showed order parameters in the range of 0.52 to 0.76. The two dyes with the longest molecular lengths were particularly interesting due to their very broad absorption spectra in the visible region. Each of these two compounds behave as single component black dye guest/host systems, which generally require a mixture of two or three dyes in the liquid crystal host. These dyes were also evaluated for use in polymer dispersed liquid crystal films. 相似文献
2.
Syntheses and spectroscopic properties of alkoxy-substituted para-acenequinones are reported. These compounds showed excellent alignment in nematic liquid crystals as evidenced by polarized UV-vis absorption and fluorescence measurements. [structure: see text] 相似文献
3.
New salen compounds have been developed to possess two pendant azo dye chromophores. The two-photon absorption properties have been observed which result from the chromophores. The additive property has been found to exist as a result of no detrimental dipole-dipole interaction between chromophores. 相似文献
4.
A series of azo-metal chelate dyes have been synthesized by coupling substituted o-nitroaniline and p-t-/s-butylphenol. The spectral characterization of the azo dyes containing o-hydroxy group and azo-metal(II) chelate [metal(II): Cu, Ni, Co] dyes by IR spectra, UV–VIS spectra, NMR spectra, elemental
analysis and magnetic susceptibility techniques are reported. The stoichiometry of the azo-metal chelates was determined by
the spectroscopic titration method to be 1:2 (ML2). 相似文献
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6.
Kiyoshi Tanaka Kazuto Nomura Hitoshi Oda Shouhei Yoshida Keiryo Mitsuhashi 《Journal of heterocyclic chemistry》1991,28(4):907-911
3-Bromo-1,1,1-trifluoropropan-2-one ( 2 ) reacted with thiourea and N-monosubstituted thioureas to give the corresponding 4-trifluoromethylthiazoles, respectively. In the reactions with N,N'-diphenylthiourea and thioamides, the considerably stable intermediates, 4-hydroxy-4-trifluoromethylthiazoline derivatives 7 and 8 , were isolated. The reaction of ethyl 2-bromo-4,4,4-trifluoro-3-oxobutanoate ( 4 ) with thiourea was carried out under the gentle conditions to give both thiazole-5-carboxylate 10 and 4-hydroxythiazoline 11 . The thiazole 10 was applied to the azo dye synthesis and the absorption maxima of thus obtained azo dyes were discussed. 相似文献
7.
3‐Amino‐2‐cyano‐4,6‐disubstituted‐thieno{2,3‐b}pyridines and 3‐aminopyridine were diazotized and coupled with 2‐phenylindole, 2‐methylindole, and 1‐methyl‐2‐phenylindole, respectively. These dyes were characterized by UV‐Visible, FT‐IR, 1H NMR, and mass spectroscopic techniques. Solvent effects on the visible absorption spectra of the dyes were evaluated. The color of the dyes is discussed with respect to the nature of the heterocyclic ring and substituent present therein. In addition, effects of temperature, concentration, as well as acid and base on the visible absorption maxima of the dyes are reported. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:622–630, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20361 相似文献
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M. E. Moustafa M. Zaky N. A. El-Khososy 《Monatshefte für Chemie / Chemical Monthly》1992,123(8-9):687-691
Summary A series of trivalent lanthanide chelates of the type [Ln(PHNSA) (H2O)
n
] (2 Cl) (whereLn
3+=Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb or Lu;PHNSA=2-(X)-phenylazo-2-hydroxynaphthalene-6-sulphonic acid;X=H, Cl, OCH3, CH3 and SO3H) have been synthesized and characterized by elemental and thermal analysis, molar conductance, IR,1H NMR (for diamagnetic complexes), electronic spectra and magnetic susceptibility measurements. IR data along with those of the1H NMR unequivocally proved that the coordination of the ligands to the metal ions took place in a bidentate fashion through the oxygen of the hydroxyl group and the nitrogen of the azo group. The magnetic moment values showed little deviation from Van Vleck values.
Synthese und Charakterisierung einiger Lanthaniden(III)-Chelate von Schaffersäure-Azofarbstoffen
Zusammenfassung Es wurde eine Reihe von dreiwertigen Lanthanidenchelaten des Types [Ln(PHNSA) (H2O) n ] (2 Cl) (mitLn 3+=Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb oder Lu undPHNSA=2-(X)-Phenylazo-2-hydroxynaphthalin-6-sulphonsäure,X=H, Cl, OCH3, CH3 und SO3H) synthetisiert und mittels Elementar- und thermischer Analyse, molarer Leitfähgigkeit, IR,1H-NMR (für diamagnetische Komplexe), Elektronenspektren und Messungen der magnetischen Suszeptibilität charakterisiert. Die IR-Daten zusammen mit1H-NMR-Befunden zeigten eindeutig, daß die Koordinierung der Liganden zum Metallion zweizähnig durch den Sauerstoff der Hydroxylgruppe und den Stickstoff der Azo-Gruppe erfolgt. Die magnetischen Momente zeigten nur eine geringe Abweichung von den Van Vleck-Werten.相似文献
10.
Riccardo Ricceri Alessandro Abbotto Antonio Facchetti Daniela Grando Gabriella Gabrielli Giorgio A. Pagani 《Colloids and surfaces. A, Physicochemical and engineering aspects》1999,150(1-3):289-296
We report on Langmuir-Blodgett (LB) films characterization of 4-[5-dicyanomethanido)thien-2-y1]-N-(n-hexadecyl)pyridinium (C16H33-PDCNT), and 1-(N-(n-hexadecy]-4-pyridinio)-2-[5-(dicyanomethanido)thien-2-yl]ethene (C16H33-PDCNTE); LB films of the pure compounds and of the mixtures of the two compounds were prepared at 291 K: UV-vis investigation revealed the presence of photobleachable absorption bands, the ones at about 530 nm and 640 nm were due to charge transfer transitions of the monomer of C16H33-PDCNT and C16H33-PDCNTE, respectively; the sharp, photobleachable ones shifted to shorter wavelengths were due to H-aggregates of the two compounds. By changing the molar ratios of the two compounds in the mixtures and in other cases by annealing the LB films, the absorption maxima of the sharp, photobleachable bands due to H-aggregates could be tuned in the range 415–467 nm. These LB films are thus very promising in view of optical data storage applications. 相似文献
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ABSTRACTIn this study, we designed, synthesised and characterised two series of cholesteric liquid crystal polymers, QP series and ZP series. With polymethylhydrosiloxane as the main chain, QP series were synthesised by copolymerisation between the monomer M1 containing a cholesteryl mesogenic unit and the monomer M2 with a hydroxyl. ZP series, meanwhile, were synthesised by esterification between QP series members and the monomer M3, a carboxylic acid with an azo mesogenic unit. We characterised chemical structures of all the monomers and polymers by FT-IR and 1H-NMR, which proved that the target monomers and polymers had been obtained. We observed dramatic colour changes after the introduction of monomer M3 and Grandjean textures from both QP series and ZP series using POM. In addition, strong selective reflection could be observed as well. Then, we characterised the thermal properties of polymers by DSC, TGA and XRD to explore their phase transition behaviours further. Their photoresponsive and photochromic properties were characterised by UV-Vis spectrum. 相似文献
13.
《Journal of Saudi Chemical Society》2014,18(5):507-512
Novel acid mono azo and mordent acid mono azo dyes were synthesized by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. The resulting dyes were characterized by spectral techniques like elemental analysis, IR, 1H-NMR and UV visible spectroscopy. The dyeing performance of all the dyes was evaluated on wool and silk fabrics. The dyeing of chrome pre-treated wool and silk fabrics showed better hues on mordented fabrics. Dyeing of wool and silk fabrics resulted in pinkish blue to red shades with very good depth and levelness. The dyed fabrics showed excellent to very good light, washing, perspiration, sublimation and rubbing fastness. 相似文献
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Hari Raghav Maradiya 《Journal of Saudi Chemical Society》2010,14(1):77-81
The synthesis of some novel monoazo disperse dyes derived from 5-acetyl-2-amino-4-methylthiazole using various N-alkyl derivatives of aniline and their dyeing performance as disperse dyes have been assessed on cellulose triacetate fabric. The spectral properties of these dyes were also measured. The dyed fabric show good light fastness, very good rubbing, perspiration, washing fastness and excellent sublimation fastness. These dyes have been found to give bright yellow to maroon color shade with very good depth and levelness on fabric. The dyebath exhaustion and fixation on fabric has been found to be very good. 相似文献
16.
The novel fluoronitroaryl azo diaminobenzene chromophores for potential NLO applications were synthesized and the effects of the position of the fluorine group on the properties of the chromophores were investigated. These chromophores exhibit high decomposition temperatures whilst keeping molecular hyperpolarizabilities similar to those of the non-fluorinated analogues. The chromophore 2,4-diamino-4′-fluoro-3′-nitroazobenzene (2R-4F-3N-DIAMINE) shows a significant UV blue shift and a combination of good transparency, high thermal stability and nonlinearity in comparison with 2,4-diamino-2′-fluoro-5′-nitroazobenzene (2R-2F-5N-DIAMINE) and its non-fluorinated analogue 2,4-diamino-3′-nitroazobenzene (2R-3N-DIAMINE). 相似文献
17.
Alaa S. Abd-El-Aziz Rawda M. Okasha Erin K. Todd Tarek H. Afifi Patrick O. Shipman K. Michelle D. Copping 《Macromolecular Symposia》2004,209(1):185-194
The synthesis of cationic cyclopentadienyliron-containing polymers with pendent azobenzene chromophores was accomplished via metal-mediated nucleophilic aromatic substitution reactions. All of the desired polymers were isolated as vibrantly coloured materials and displayed excellent solubility in polar aprotic solvents. Cationic and neutral cyclopentadienyliron polymers incorporating azo dyes in the backbone were also prepared. Reactions of azo dyes with dichlorobenzene complexes allowed for the isolation of cationic cyclopentdienyliron (CpFe+) complexes with azo dye chromophores. These complexes were then reacted with 1,1′-ferrocenedicarbonyl chloride to produce the trimetallic monomers with terminal chloro groups. These monomers contained two pendent CpFe+ cations and a neutral iron moiety in the backbone. Nucleophilic substitution reactions of these monomers with oxygen and sulfur containing dinucleophiles gave rise to a new class of polymeric materials. The pendent CpFe+ moieties could also be cleaved from the polymer backbones using photolysis to afford novel ferrocene based polymers. The UV-vis spectra of the organoiron monomers and polymers display similar wavelength maxima however incorporating azobenzene chromophores with electron-withdrawing substituent into the polymer chains resulted in bathochromic shifts of the λmax values. 相似文献
18.
Luiz Fernando C. de Oliveira Maurício A. P. Silva Adílson R. Brandão Rodrigo Stephani Carlos Ivan R. de Oliveira Rogéria R. Gonçalves Anne J. Barbosa Hernane S. Barud Younes Messaddeq Sidney J. L. Ribeiro 《Journal of Sol-Gel Science and Technology》2009,50(2):158-163
Amorphous Mn2+ polyphosphate materials were prepared at room temperature through the coacervation of polyphosphate solutions. These new
materials display the typical Mn2+ red emission with a broad band centered at 15,290 cm−1 (bandwidth—1,320 cm−1). Excitation spectra display typical Mn2+ (d5) absorption bands assigned to transitions from the 6A1g ground state to the 4T2g, (4A1g, 4Eg), 4T2g, and 4T1g Mn2+ excited states. Transition energies allow estimating the Mn2+ ligand field strength as intermediate between the one observed in Mn2+ aqueous solutions and the one observed in Mn2+ phosphate glasses. Azo dyes, methyl red and methyl orange, were incorporated into the manganese polyphosphate coacervates
structure. Raman scattering and visible light reflectance results show azo dyes acid forms inside the hydrated polyphosphate
structure and sensitivity to the atmosphere pH. Release of azo dyes species was observed from these new solid hybrid materials
in aqueous medium. 相似文献
19.
Mohsen K. A. Regal El-Hady Rafat Nour E. A. Abd El-Sattar 《Journal of heterocyclic chemistry》2020,57(3):1173-1182
A string of novel heterocyclic mono azo dyes were synthesized and their utilization in dyeing different fabrics as wool and nylon were discussed. Thienopyridine azo dyes 4 and 6 were prepared by reaction of chloro acetamidederivative 2 with diamino compounds to yield 3 and 5 , followed by reaction with NaNO2/HCl and coupling with nucleophilic reagent. One-pot reaction of chloro acetamide 2 with ammonium thiocyanat in solvent ethanol gave the unexpected thienopyrimidine derivative 7 , which contain two active sites, the former is primary amine that was able to form diazonium salt that coupled with N,N-dimethylaniline, resorcinol, and/or self-coupling to afford the azo dyes 8-10 , and the latter is active methylene group that underwent coupling with different diazonium salts to give the azo thienopyrimidine derivative dye 11-15 . The dyeing performance of these azo dyes had been investigated in terms of their dyeing behavior and fastness properties on different fabrics. Results showed that the color strength (K/S) values, as well as, washing, rubbing, and resistance to acid, alkali and light showed high efficiency of these heterocyclic mono azo dyes to dye wool rather than nylon fibers. 相似文献
20.
A linear and nonlinear optical spectroscopic characterization is carried out on three azo dyes (Reactive orange 1, Reactive violet 8, and Acidproof purplish red), and on N-(p-hydroxybenzylidene)-diamino-maleonitrile. Fluorescence quantum distributions, fluorescence quantum yields, and fluorescence lifetimes are measured. The saturable absorption is studied by nonlinear transmission measurements with intense picosecond laser pulses. The ground-state absorption recovery is studied by picosecond time-resolved pump and probe measurements. Absolute ground-state absorption cross-sections, excited-state absorption cross-sections, and dye concentrations are extracted from saturable absorption studies. The azo dyes have fluorescence lifetimes and ground-state absorption recovery times of around 2 ps and their excited-state absorption cross-sections are small (measured at 527 nm) making them good mode-locking dyes for picosecond and femtosecond lasers. The investigated diamino-maleonitrile dye exhibits sub-picosecond fluorescence lifetime and slow ground-state absorption recovery (>1 ns). 相似文献