Showing papers on "Xanthene published in 1991"

High chroma color dye-set for use in ink-jet inks employing polysaccharide-containing vehicles

Abstract: A set of dyes is provided for use in vehicles employing high molecular weight saccharides. The dye-set comprises about 1 to 4% xanthene magenta, about 0.9 to 2% of a mixture of Acid Yellow 23 and Direct Yellow 86, and about 0.75 to 2.5 of Acid Blue 9 or a mixture of Acid Blue 9 and a copper phthalocyanine dye containing not more than about 25% copper phthalocyanine. The particular dye-set evidences the following properties: good crusting resistance, good stability, the proper viscosity, the proper surface tension, recognizable secondaries, high color saturation, little color-to-color bleed, rapid drytime, no negative reaction with the vehicle, be highly soluble in the vehicle, consumer-safe, and low strike-through.

Poly(oxyalkylene) substituted aminophenol intermediate and xanthene colorant

Abstract: A poly(oxyalkylene) substituted xanthene colorant is providing having the following structure: ##STR1## where Y is a poly(oxyalkylene) substituent having a straight or branched polymer chain of from 3 to 400 monomer units selected from ethylene oxide, propylene oxide, butylene oxide and glycidol; R 1 and R 2 are independently selected from H, C1-C8 alkyl, aryl and Y, provided that if either R 1 or R 2 are Y, the other is not H; R 3 and R 4 are independently selected from H, C1-C4 alkyl, C1-C4 alkoxy, Cl, Br and I; X is selected from H, SO 3 --, CO 2 -- and COOR 5 , where R 5 is C1-C4 alkyl or aryl; and each Z is independently selected from SO 3 --, CO 2 --, COOR 6 , Cl, and OH, where R 6 is C1-C4 alkyl or aryl, and n is 0, 1, 2 or 3. The colorant is synthesized using a novel poly(oxyalkylene) substituted aminophenol intermediate.

Photosensitized electron injection from xanthene dyes incorporated in Langmuir-Blodgett films into tin dioxide electrodes

Abstract: Anodic photocurrents are obtained upon excitation of xanthene dyes incorporated into Langmuir-Blodgett films deposited on SnO{sub 2}. The observed quantum yield of the photocurrent strongly depends upon the applied electrode potential, the regenerator (hydroquinone) concentration, and the pH of the electrolyte. The photocurrent is nearly independent of the chemical structure of the dye or the amount of dye incorporated in the monolayer. For 3,6-bis(N-ethyl-N-octadecyl)aminoxanthylium perchlorate (PYR18) and N,N{prime}-dioctadecylrhodamine 119 (RH18), the photocurrent action spectra resemble the absorption spectra of the mixed monolayer or a dilute solution of the dye in chloroform. Interactions between the chromophore and the cadmium arachidate matrix shift the spectral sensitization maximum of the surface-active bis(N-ethyl-N-octadecyl)rhodamine (RB18) to shorter wavelengths than the absorption maximum of the mixed monolayers or the action spectra of adsorbed rhodamine B. As observed for adsorbed rhodamine B the action spectra give no indication for the formation of sandwich dimers for RB18 and RH18. Analysis of Mott-Schottky plots obtained at low frequency indicates that decreasing the electrolyte pH leads to an anodic shift of the flat-band potential (E{sub fb}) and that the electrode is only partially covered by the deposited Langmuir-Blodgett film.

Separation of the α-Tocopherol Model Compound 2,2,5,7,8-Pentamethyl-6-Chromanol from its Oxidation Products by High Performance Liquid Chromatography

Abstract: A rapid method is described for the separation of the α-tocopherol model compound, 2,2,5,7,8-pentamethyl-6-chromanol (6), from 9 of its oxidation products in a single 35 minute run. Separated derivatives of 6, in order of elution, included the 5-cholesteroxymethyl (1), spirotrimer (2), spirodimer (3), 5-formyl (4), 5-ethoxymethyl (5), dihydroxydimer (7), chroman dione (8), quinone (9) and pyrano xanthene (10). A normal phase system, using gradient elution is employed, the eluent being monitored at 290 nm. The minimum detection limit for compounds 1–8 was 0.1 μg per injection and for compounds 9 and 10 it was 0.3 μg per injection.

9,9-bis (perfluoroalkyl) xanthene, 9-aryl-9-perfluoroalkylxanthene, monomers and polymers derived therefrom

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis-(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Diffusionless Electron Transfer of Xanthene Dyes in Nonpolar and Weakly Polar Donor- and Acceptor-Solvents

Abstract: Diffusionless electron transfer systems, comprised of excited xanthene dyes dissolved in nonpolar or weakly polar electron donor or acceptor, are distinguished by their direct access to the rate constant of electron transfer and by their potentiality for ultrafast electron transfer. We observed short fluorescence lifetimes of ≤ 6 ps for rhodamine 6G dissolved in p-benzoquinone, aniline and N,N-dimethylaniline.

Optical Properties of Dyes Incorporated into Clay

Abstract: Optical properties of xanthene and coumarine dyes incorporated into a swelling clay were studied. Preparation of the dye-clay composites were carried out as follows; a swelling clay was added and thoroughly mixed into various solvents containing the corresponding quantity of dye. After about one week, the resulting composites were quickly recovered by filtration and washed several times with solvent, then dried overnight at 100°C in air. The TG-DTA and the X-ray diffraction data showed that the intercalated dye molecules were immobilized and thermally stabilized over their melting temperatures. Also, the basal spacings of the clay were expanded up to the molecular size of dyes with slight distortion of the layer structure on increasing the dye content. All the dominant fluorescences were observed, which were identified as the π — π * transition related to the mesomeric structure of dye chromophore. Its quantum efficiency is briefly discussed in connection with concentration quenching phenomena.

Structure Analysis of a Coloring and Decoloring Unsymmetrical Fluoran Dye by Carbon-13 Nuclear Magnetic Resonance Method

Abstract: Unsymmetrical fluoran dyes whose coloring-to-decoloring reversible reaction depends upon the acidity are used in heat-Sensitive recording systems. The reversible reaction corresponds to open-to-closed forms of the lactone ring. We observed remarkable chemical shift differences in 4 species of 13C NMR signals between open- and closed-forms of the lactone ring of an unsymmetrical fluoran dye, 3-diethylamino-6-methyl-7-chlorofluoran (DEAMCF) in CDCl3. According to the optimized molecular structure of DEAMCF by a semi-empirical molecular orbital (MO) Austin Model 1(AM 1) method, the xanthene moiety in colorless form is folded at 166 degree around the C(spiro)-O(xanthene) axis, and the benzolactone moiety is almost perpendicular to the xanthene moiety. The moiety in color form for a molar DEAMCF/H2SO4 ratio of 1/2.2 becomes almost planar and has canonical structure, while the lactone ring opens, according to NMR and MO analyses.

Production of n-alkylaminophenols

Abstract: PURPOSE:To obtain the subject compound by reacting bifunctional phenols and alkylamine, converting tie subject compound to salt with acid treatment of reacted mixture, removing unreacted bifunctional phenols with extraction and separation in organic solvent, neutralizing residual salt and distilling. CONSTITUTION:Bifunctional phenols are reacted with alkylamine and resultant reacted mixture is treated with acid to convert to N-alkylaminophenols salt. Next, unreacted bifunctional phenols are extracted and separated in organic solvent. On the other hand, residual N-alkylaminophenolic acid salt is neutralized with alkaline aqueous solution and separated oil layer is distilled to obtain N-alkylaminophenols. Resultant compound is useful as intermediate of dye for heat-sensitive and pressure-sensitive paper, xanthene-based dye or fluorescent dye. Produced compound is readily and efficiently purified with excellent reaction efficiency, high conversion of bifunctional phenols and a small amount of by-product.

Water-soluble fiber-reactive dyes and preparation and use thereof

Abstract: Anthraquinone, phthalocyanine, formazan, azomethine, dioxazine, phenazine, triphenylmethane, xanthene, thioxanthone, nitroaryl, naphthoquinone, pyrenequinone and perylenetetracarbimide dyes which contain one or two groups of the general formula ##STR1## where Y is vinyl or an ethyl group which contains in a β-position a substituent which is eliminable by means of alkali to form a vinyl group, and W is a direct bond or a group of the general formula ##STR2## where M is a hydrogen atom or an alkali metal and n is zero, 1 or 2. The dyes have very good fiber-reactive properties and are advantageously suitable for dyeing carboxamino- and/or hydroxy-containing material, for example wool, in particular cellulose fiber materials; on these materials they produce strong fast shades in a high degree of fixation.

In vitro effects of synthetic dyes on the syntheses of prostaglandin E2 (PGE2) and 5-hydroxyeicosatetraenoic acid (5-HETE).

Abstract: The effects of thirty-one synthetic dyes (tar dyes in Japan), which are permitted in cosmetics, on three different enzymes were evaluated as an initial step in developing in vitro safety screens. The activities of the prostaglandin (PG)-synthetase from rabbit renal medulla and the lipoxygenases from potato tubers and guinea pig peritoneal polymorphonuclear leukocytes (PMN) were determined based on the biosyntheses of PGE2 and 5-hydroxyeicosatetraenoic acid (5-HETE), respectively. Xanthene dyes with halogen substituents exhibited marked inhibition on the PG-synthetase. Among the dyes which are permitted for any pharmaceutics and cosmetics, only the xanthene dyes exhibitec inhibitory effects on the PG-synthetase at 2.5 mM. The xanthene dyes also showed inhibition and stimulation of potato lipoxygenase and PMN lipoxygenase, respectively.

Polyester from 9,9-bis(perfluoroalkyl)xanthene diol or 9-aryl-9-perfluoroalkylxanthene diol

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Preparation and reactions of anthrone and xanthene―triphenylphosphonium salts. A facile and efficient approach to alkylation and alkenylation of cycles and heterocycles

Abstract: Triphenylphosphonium salts (3) of 10,10-dibromoanthrone (1a) and 9,9-dichloroxanthene (1b) were prepared and generalized reactions for the salts (e.g. Wittig reaction, hydrolysis and thermolysis) were suggested and illustrated using the aforementioned species.

Polyethers based on 9,9-bis-perfluoroalkyl-3,6-dihydroxy-xanthene or 9-aryl-9-perfluoroalkyl-3,6-dihydroxy-xanthane

Abstract: Polyethers based on 9,9-bis-perfluoroalkyl-3,6-dihydroxy-xanthene or 9-aryl-9-perfluoroalkyl-3,6-dihydroxy-xanthene and another constituent selected from aryl, sulfone, aryl ketone, benzonitrile, and imide. These polyethers are useful as dielectric films in electronic devices.

Influence of the degree, position and nature of the halide substitution on the rate of photobleaching of xanthene dyes.

Abstract: Aqueous solutions of xanthene dyes irridiated with visible light generate singlet oxygen in various quantum yields and are therefore used as sensitizers for photochemical reactions (Lamberts and Neckers 1984). Xanthene dyes might be suitable for the elucidation of photo degradation of pharmacologically active drugs, e.g. amiodarone and thyroxine. These compounds contain ortho-iodinated phenoxy groups as structural elements and easily are decomposed. Relatively high photobleaching is disadvantageous. Kinetic analysis of the rates of photobleaching of ten differentially substituted xanthene dyes served to investigate the influence of the degree, the position and the nature of the halide substitution on the photostability.

Fiber-reactive dyes which contain a ureidoalkylene group

Abstract: Water-soluble fiber-reactive dyes are described conforming to the below-indicated formula (1) which are capable of dyeing hydroxyl- and/or carboxamido-containing material, in particular fiber material, such as wool and in particular cellulose fiber materials, in strong, fast shades. ##STR1## in which F is the radical of a monoazo, polyazo, metal complex azo, anthraquinone, phthalocyanine, triphenoldioxazine, azomethine, dioxazine, phenazine, stilbene, triphenylmethane, xanthene, formazan, thioxanthone, nitroaryl, naphthoquinone, pyrenequinone or perylenetetracarbimide dye; Rx is hydrogen or alkyl of 1 to 4 carbon atoms; R is hydrogen, sulfo, carboxyl, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms or chlorine; w is 1, 2, 3 or 4; Y is vinyl or an ethyl group which contains in the β-position a substituent which is eliminable by alkali to form a vinyl group; n is 1 or 2.

HYDRODEOXYGENATION OF XANTHENE OVER A SULFIDED CoMo/Al2O3 CATALYST

Abstract: Publisher Summary This chapter describes the hydrodeoxygenation of xanthene over a sulfided CoMo/Al2O3 catalyst. Oxygen removal from coal liquids is required to ensure fuel stability during storage and before further processing. Important interactions may occur between hydrodeoxygenation and other hydroprocessing reactions. The chapter describes a study in which the effect of temperature on the hydrodeoxygenation of xanthene at 200–350°C and 5.1 MPa H2 pressure is discussed. The conversion of xanthene was 36.6% and 95%, but the recoveries were 81% and 60% at 200°C and 300°C, respectively. Diphenylmethane was formed from the C–O hydrogenolysis of xanthene and then cyclohexylphenylmethane and di-cyclohexylmethane, whereas diphenylether was not formed in the C–CH2 hydrogenolysis of xanthene. Hydrogenated compounds were barely observed. This result showed that the direct extrusion of oxygen of xanthene to diphenylmethane was greatly higher than that of the steps involving ring hydrogenation and C–CH2 hydrogenolysis. A large amount of cyclohexylphenylmethane, followed by benzene and toluene, were formed, but cyclohexane and methylcyclohexane was produced as the reaction temperature was increased. The chapter describes the changes in the amounts of diphenylmethane and cyclohexylphenylmethane as a function of the concentration of xanthene for keeping the hydrogen pressure constant at 5.1 MPa.

Water-soluble dyes which react with fibres, process for producing them and their use.

Abstract: Water-soluble dyes of general formula (1) which react with fibres are capable of dyeing materials containing hydroxy or carbonamide groups, in particular fibrous materials such as wool and in particular cellulose fibre material, in bright, fast shades. In (1), F is the residue of a monoazo, polyazo, metal complex azo, anthraquinone, phthalyocyanin, triphendioxazine, azomethine, dioxazine, phenazine, stilbene, triphenylmethane, xanthene, formazane, thoixanthene, nitroaryl, naphthaquinone, pyrene quinone or perylene tetracarbonamide dye, Rx is hydrogen or alkyl containing from 1 to 4 carbon atoms, R is hydrogen, sulpho, carboxy, alkyl containing from 1 to 4 carbon atoms, alkoxy containing from 1 to 4 carbon atoms or chlorine, w is equal to 1, 2, 3 or 4, Y is the vinyl group or an ethyl group containing a substituent in the β position which can be removed by alkali to form the vinyl group, and n is equal to 1 or 2.