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  • 1
    Electronic Resource
    Electronic Resource
    β-NMR on single-crystal surfaces: Method (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 2465-2475 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new and highly sensitive β-NMR method to study adsorbates on single-crystal surfaces is presented. Contrary to conventional NMR, this method combines (via optical pumping) a high, nonthermal polarization of the adsorbed species with a particle counting method. Here, the β-active isotope 8Li is produced in the nuclear reaction D(7Li, 8Li)H using a high-pressure deuterium gas target. The fast 8Li ions are subsequently implanted into a hot graphite block where they thermally diffuse to the surface and desorb. The desorbing thermal velocity 8Li atoms are shaped into an atomic beam. Using a frequency modulated laser beam the atoms are transferred into a single hyperfine state by optical pumping. The so-achieved nuclear polarization of the atoms (before impinging on the single-crystal surface) is approximately 0.8 and can be switched in sign by an adiabatic high-frequency transition. The atoms adsorb on the single-crystal surface and their polarization—either freely decaying on the surface or driven by an external radio-frequency field—is observed via the decay asymmetry of the nuclear β-decay of the 8Li nuclei. This method realizes an effective sensitivity to the active NMR isotope of 5×103 atoms/cm2, which corresponds to a stationary coverage of 10−11 of a monolayer. The typical electron count rate is 400 Hz during β-NMR experiments. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145644
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  • 2
    Electronic Resource
    Electronic Resource
    Reorganisation of electronic shells after stripping (1988)
    Springer
    The European physical journal 9 (1988), S. 117-123 
    Details
    ISSN: 1434-6079
    Keywords: 29.25.Cy ; 34.70.+e ; 34.90.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Depolarization (i.e. dealignment) after stripping of a fast nuclear spin polarized sodium ion beam and its dependence on the charge state is investigated experimentally. A model of the population mechanism of the He-like fraction is discussed. The importance ofK-vacancies and autoionizing three electron systems is stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01384261
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  • 3
    Electronic Resource
    Electronic Resource
    3-Amino-benzo[b]furane (1973)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 779-785 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die aus o-Cyanphenolen und α-Halogencarbonylverbindungen erhältlichen o-Cyanphenoläther 1, cyclisieren in Gegenwart von Natriumalkoholat zu 2-substituierten 3-Amino-benzo[b]furanen 2. Eine Folgereaktion von 2. ist die Kondensation zu Benzofuropyrimidinen 6 - 8.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19733150423
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  • 4
    Electronic Resource
    Electronic Resource
    Darstellung von 1-Cyan-4-dimethylamino-3-(pyrid-4-yl)-buta-1,3-dien-1-carbonsäure-Derivaten und ihre Cyclisierung zu 3-substituierten 2-Amino-5-(pyrid-4-yl)-pyridinen sowie den entsprechenden 1-OxidenAkademie der Wissenschaften der DDR (Erf. Hagen, V.; Rumler, A.; Niedrich, H.; Lohmann, D.; Jänsch, H.-J.; Faust, G.; Heidrich, H.-J.) Wirtsch.-Pat. DDR, 263 758 (11. Januar 1989) (1990)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 748-754 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 1-Cyano-4-dimethylamino-3-(4-pyridinyl)-1,3-butadiene-1-carboxylic Acid Derivatives and Their Cyclisation to 3-Substituted 2-Amino-5-(4-pyridinyl)-pyridines Including the Corresponding 1-OxidesThe vinylogous amidinium salt 1 is transformed to 1-cyano-4-dimethylamino-3-(4-pyridinyl)-1,3-butadiene-1-carboxylic acid derivatives 3a-f by reaction with the cyanoacetic acid compounds 2a-f in the presence of bases.Treatment of the 3a-f with ammonia and hydroxylamine yields the 2-amino-5-(4-pyridinyl)-pyridine-3-carboxylic acid derivatives 5a-f and the corresponding 1-oxides 6a-f, respectively. The products 5d, e are also prepared via the 6d, e by reduction with phosphorus trichloride.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19903320525
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  • 5
    Electronic Resource
    Electronic Resource
    3-Amino-furo[2.3-b]pyridine (1976)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 318 (1976), S. 313-320 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-Amino-furo[2,3-b]pyridinesThe reaction of the 3-cyano-2-pyridones 1 with α-halogen carbonyl compounds yields 2-alkoxy-pyridines 2 which can be cyclized in the presence of sodium ethoxide to form 3-amino-furo[2,3-b]pyridines 3. From 4,6-dimethyl-3-cyano-2-pyridone, mixtures of N- and O-alkylated compounds are obtained which by cyclization in addition to 3-amino-furopyridines 6 yield indolizinones 7. From 3, pyridofuro-pyrimidines 9 can be synthesized.
    Notes: Die 6-substituierten 3-Cyan-pyridone-(2) 1 reagieren mit α-Halogen-carbonylverbindungen zu 2-Alkoxypyridinen 2, die in Gegenwart von Natriumalkoholat zu substituierten 3-Amino-furo[2.3-b]pyridinen 3 cyclisieren. Aus dem 4.6-Dimethyl-3-cyan-pyridon-(2) erhält man dabei Gemische der N- und O-Alkylverbindungen, die bei der Cyclisierung 3-Amino-furopyridine 6 neben Indolizinonen 7 liefern. 3 eignet sich zur Darstellung von Pyridofuropyrimidinen 9.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19763180216
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