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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 263 (1973), S. 27-32 
    ISSN: 1618-2650
    Keywords: Esterase ; in Polyacrylamidgel inkludierte Kartoffelesterase ; Elektrophorese, Gel ; Inklusion von Kartoffelesterase in Polycrylamidgel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary An isoenzyme of potato esterase has been entrapped in situ after polyacrylamide (PAA)-electrophoresis, using PAA of different concentrations and crosslinking. Best results in respect to diffusion, flow rates and yield (77%) have been found for a gel containing 6% acrylamide with 6% methylen-bis-acrylamide, penetrating a gel of cyanogum with esterase. The latter is stabilized during polymerization by the gel. Properties of the entrapped enzyme (pHi, K m, MW etc.) have been determined, 100 fold better storage stability is achieved.
    Notes: Zusammenfassung Von den Kartoffelesterasen wurde ein Isoenzym durch Gel-Elektrophorese in Polyacrylamid (PAA) getrennt. Das entsprechende Gelstück mit dem durch das Netzwerk stabilisierten Enzym tränkte man mit AA und Vernetzer (BIS) unterschiedlicher Konzentration und polymerisierte mit Licht das Enzym ein. Die Mischungen AA/BIS sind in einem bestimmten Verhältnis (6∶0,36) optimal., eine Ausbeute von 77% der Anfangsaktivität kann erreicht werden. Einige Eigenschaften (pHi, K m, MG u.ä.) werden beschrieben, insbesondere ist die 100fach bessere Lagerstabilität hervorzuheben.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Alkylurotropiniumpolyiodides  -  Preparation, Investigation of the Electrical and Magnetic PropertiesThe formation of N-alkylurotropiniumpolyiodides is investigated by a potentiometric technique. The polyiodides are prepared, analysed and the electrical and magnetic properties are measured. All prepared polyiodides are diamagnetic. The magnetic susceptibility doesnť depend on the magnetic field strength and on the temperature. The electrical conductivity increases with increasing iodine contents. The values are between 10-11S/cm for the triiodides and 10-5S/cm for the heptaiodides. The current passage is realized with priority by electrontransfer in the anion lattice.
    Notes: Mittels einer potentiometrischen Meßanordnung wird die Bildung von N-Alkylurotropiniumpolyiodiden untersucht. Die Polyiodide werden präpariert, analysiert und ihre elektrischen sowie magnetischen Eigenschaften gemessen. Alle dargestellten Polyiodide sind diamagnetisch. Die magnetische Suszeptibilität ist unabhängig von der magnetischen Feldstärke und der Temperatur. Die elektrische Leitfähigkeit steigt mit dem Iodgehalt. Sie liegt bei Raumtemperatur zwischen 10-11S/cm für die Triiodide und 10-5S/cm für die Heptaiodide. Der Stromtransport wird vorrangig durch Elektronenüberführung im Anionenteilgitter realisiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Palladium-Catalyzed Telomerization of Isoprene in Alcoholic Mediums and its Consecutive ReactionsThe telomerization of isoprene with methanol to give dimethyloctadienylmethylethers by palladium-containing homogenous catalysts was investigated. It was found that the primary products of the catalysis undergo different consecutive reactions catalysed by the same catalytic systems. These reactions, i.e. isomerization, ether cleavage, interchange reaction and oligomerization were investigated in greater detail. A reaction scheme is developed and discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 947-954 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Palladium-Catalyzed Addition of Methanol to IsopreneThe soluble systems containing palladium(II)-compounds and tri-n-butylphosphine as a ligand catalyze the addition of methanol to isoprene to give methoxyisopentenes in goodyields. Activity and selectivity of the reaction are dependent on the ligand, the ratio ligand to palladium and in a surprising manner on the concentration of methanol.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 20 (1989), S. 251-255 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: N-Alkylurotropinium polyiodides, UrRIx, with different iodine contents and different sizes of alkyl group were investigated by Raman spectroscopy. The spectra were recorded for wavenumber shifts up to 500 cm-1. It was found that the triiodides, UrRI3, contain a symmetrical linear I3- ion. The pentaiodides, UrRI5, contain no triiodide unit; the anion structure can be described as nearly symmetrical, rectangular L-shaped I5-. An interpretation of the Raman spectra of the heptaiodides, UrRI7, is that the anion corresponds to an I5-. I2 structure. This is the first proof of such a heptaiodide. A review of previously published data on the Raman spectra of polyiodides is also given.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 22 (1991), S. 627-631 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Solid polybromide-containing functional polymers were obtained from basic anion-exchange resins. The chloride or hydroxide anions of the commercial resins were exchanged by bromide, then dried under anaerobic conditions and allowed to react with a gaseous bromine phase. The formation of linear, slightly asymmetric tribromides was proved by Raman and far-IR spectroscopy. The tribromide spectra are characterized by the symmetrical stretching vibration ν1 at about 160 cm-1 and the antisymmetric stretching vibration ν3 at about 200 cm-1. If the Br2: Br- molar ratio is greater than 1 an additional band could be observed at about 255 cm-1. This band is assigned to the stretching vibration of coordinated bromine. It is shifted in the direction of free bromine at about 300 cm-1 with increasing bromine content in the functional polymers. According to the spectroscopic results, the anion structure in amorphous polybromide-containing functional polymers can be explained by tribromide ions and bromine molecules interacting with the tribromide. The thermal instability of higher polybromides was also proved spectroscopically.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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