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  • 2020-2022
  • 2015-2019
  • 1960-1964  (11)
  • 1920-1924
  • 1905-1909
  • Dyes/Pigments  (7)
  • Catalysis  (4)
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  • 1
    ISSN: 0570-0833
    Schlagwort(e): Proton transfer ; Catalysis ; Enzyme catalysis ; Hydrolysis ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The proton occupies a special position as a promoter and mediator in chemical reactions occurring in solution. Many reactions in organic chemistry are catalysed by acids or bases; likewise, most enzymes contain active groups which promote acid-base catalysis. To understand the reaction mechanisms involved, it is necessary to identify the elementary steps as well as their course in time. Systematic investigation of these elementary steps as well as their course in time. Systematic investigation of these elementary steps has become possible only with the development of new methods for studying very fast reactions. The present paper reviews the information obtained in this type of investigation. The result is a relatively complete picture of the elementary proton transfer mechanisms and a comprehensive description of the modes and laws of acid-base and enzymatic catalysis.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 93-101 
    ISSN: 0570-0833
    Schlagwort(e): Organometallic catalysts ; Catalysis ; Reaction mechanisms ; Lithium ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Kinetic investigations of the polyreaction of isoprene with organolithium compounds as initiators in n-heptane as solvent indicate the following sequence of reactions: 1. formation of an adduct between a monomeric form of the organolithium compound and the isoprene and 2. reaction of this adduct with an associated form of the organolithium compound with insertion of the isoprene. The adduct formation is considered to be due to chemisorption, and proof of such chemisorption of a monomer (ethylene) is also demonstrated for a homogeneous Ziegler-type catalyst. All the reactions can be formulated in the form of cyclic structures with electron-deficient character. Postulation of such ring structures explains the surprising values obtained for the frequency factors and equilibrium constants.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 408-416 
    ISSN: 0570-0833
    Schlagwort(e): Reactive dyes ; Dyes/Pigments ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Two new groups of reactive dyestuffs have been developed. One group (Levafix® dyes) comprises compounds which contain —SO2NH—CH2—CH2—OSO3H or —CH2—N(alkyl)-CH2—CH2—OSO3H as reactive groups. The dyes of this group react with cellulose fibers to form cellulose ethers, e.g. R—SO2NH—CH2—CH2—O—cellulose. The substances in the second group (Levafix-E® dyes) consist of the amides formed from 2,3-dichloroquinoxaline-6-carboxylic acid and dyestuffs containing primary or secondary amino groups.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 185-191 
    ISSN: 0570-0833
    Schlagwort(e): Coordination modes ; Catalysis ; Cyclooctatetraenes ; Reppe chemistry ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The relationship between the structure and the catalytic activity of nickel(II) complexes in the synthesis of cyclooctatetraene by the method of W. Reppe is discussed. The cyclotetramerization of acetylene takes place within labile Ni(II)-acetylene π-complexes. Inhibition tests have made it probable that four molecules of acetylene are grouped around the nickel ion in the transition state, in a configuration which favors the formation of the eight-membered ring.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 2 (1963), S. 20-23 
    ISSN: 0570-0833
    Schlagwort(e): Reactive dyes ; Dyes/Pigments ; Reactive dyes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Compounds and dyes containing vinylsulfonyl groups or groupings which readily yield vinylsulfonyl groups possess a marked ability to add onto many compounds containing active hydrogen under alkaline conditions. They also react with natural substances of high molecular weight, e.g. wool and cellulose, which contain amino- or hydroxyl groups. These reactions lead to the formation of strong covalent bonds between the reactants. As a result of this finding, reactive dyes for nitrogenous and cellulose fibers have been developed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 0570-0833
    Schlagwort(e): Polycondensation ; Dyes/Pigments ; Bunte salts ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Dyes which contain only thiosulfate residues as water-solubilizing groups are readily polycondensed on cellulose under mild conditions in the presence of condensing agents such as sodium sulfide to give insoluble, high molecular-weight dyes. This type of fixation leads to wash-fast dyeings and, in contrast to reactive dyes, involves no reaction with the fiber. The preparation and application of the dyes are described.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 41-45 
    ISSN: 0570-0833
    Schlagwort(e): Dyes/Pigments ; Rutile structure ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Until the present time, new color pigments have been developed by isotypic and homotypic mixed-phase formation. This paper deals primarily with heterotypic mixed-phase formation for the preparation of new colored and white pigments with the rutile structure. Dioxides and difluorides crystallizing in the rutile lattice-form were chosen as host-lattices for the mixed-phase formation. Hosts of the general formula AB2 can accommodate, as guests, in the form of solid solutions, oxides and/or fluorides with different structures. Characteristically, the mean statistical cation-radius lies between 0.55 and 0.98 Å, with single radii between 0.46 and 0.98 Å. Relative quantities are so chosen that the cation to anion ratio of 1:2 prescribed by the host lattice, as well as electroneutrality, is maintained.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 80-88 
    ISSN: 0570-0833
    Schlagwort(e): Oxidation ; Palladium ; Catalysis ; Alkenes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The oxidation of olefins to carbonyl compounds with palladium compounds, especially the oxidation of ethylene to acetaldehyde, is at present carried out on a technical scale. The reaction takes place via a palladium-olefin complex, the formation of which is inhibited by halide ions. Hydrolysis to the carbonyl compound is inhibited by hydrogen ions. The knowledge gained by studying the reaction of olefins with pure solutions of palladium salts allows important conclusions to be drawn concerning the action of technical catalyst solutions containing copper and palladium chloride.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    ISSN: 0570-0833
    Schlagwort(e): Azo dyes ; Dyes/Pigments ; Oxidative coupling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: New findings in the field of oxidative coupling reactions are reported. These involve: extension of this type of reaction to amidrazone system displaying (vinylogous) tautomerism and to unsymmetrical diarylhydrazines; elucidation of the coupling mechanism for these arylhydrazines and for the amidrazone systems previously described; the properties of some dyes, complexed with heavy metals, and the synthesis of tetraazapentamethine and penta-azapentamethine dyes.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 532-537 
    ISSN: 0570-0833
    Schlagwort(e): Polyacrylonitrile ; Fibers ; Azatrimethinecyanines ; Dyes/Pigments ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Like all basic dyes, azatrimethinecyanines possess a good dyeing affinity for acrylic fibers. Compounds with isolated nitrogen atoms in the trimethine chain show insufficient light fastness, whereas good to excellent fastness to light is displayed by compounds having neighboring nitrogen atoms in the chain. Thus, a working hypothesis stating that the light fastness of trimethinecyanines on acrylic fibers is improved by progressive replacement of methine groups by nitrogen atoms has been partially confirmed.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 568-572 
    ISSN: 0570-0833
    Schlagwort(e): Trichloropyrimidyl dyes ; Dyes/Pigments ; Dichloropyrimidyl dyes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Several examples are used to show that the reactivity of dichloro- and trichloropyrimidyl dyes and the sensitivity of their dyeings to hydrolysis are determined by the nature of the bridge unit between the chromophore and the reactive system. The tendency of the dyeings to hydrolyze in acid and, more particularly, in alkaline media increases with increasing reactivity of the dyes. In alkaline media, dyeings made with dyes containing oxygen bridges are cleaved mainly between the reactive system and the chromophore, while in dyeings made with dyes containing imino or methylimino bridges, the linkage between the reactive system and the cellulose is hydrolyzed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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