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'Mass Spectrometry' in keywords Facet   Publication Year 1979  [X]
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1Author    Dietmar Kuck, Hans-Friedrich GrützmacherRequires cookie*
 Title    Der Einfluß der Kettenlänge auf die massenspektrometrigche Fragmentierung höherer l.co-Diphenylalkane The Influence of the Chain Length on the Mass Spectrometric Fragmentation of Higher 1, co-Diphenylalkanes  
 Abstract    The mass spectrometric fragmentation of l,co-diphenylalkanes (2 < co < 22) has been studied in order to elucidate the effect of the chain length on the reactions of unstable and metastable molecular ions with respect to the occurrence of internally solvated ions in the gas phase. The unstable molecular ions of all l,co-diphenylalkanes react predominantly by formation of C?H7+ and C7Hg + " ions, the latter ones are also formed by metastable molecular ions. Neither the variation of the relative abundances of these fragment ions with the chain length nor the fragmentation of specifically deuterated molecular ions indicate any internal solvation in the reacting ions. Inspite of the localized activated C-H bonds at the benzylic positions, these "activated" H atoms are not involved in intra-molecular hydrogen exchange reactions or the formation of C7Hs + ' ions (with the exception of co = 3). Especially the higher homologues (co > 12) react very similarly to the molecular ions of 1-phenylalkanes, while the fragmentation of the lower homologues (co < 6) is determined by specific ("vinculoselective") competitive reactions, e.g. loss of CvH?' and CsHs. 
  Reference    Z. Naturforsch. 34b, 1750—1764 (1979); eingegangen am 12. Juli 1979 
  Published    1979 
  Keywords    Mass Spectrometry, 1, co-Diphenylalkanes 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1750.pdf 
 Identifier    ZNB-1979-34b-1750 
 Volume    34 
2Author    KlausG. Heumann, Paul Roßmann, Anni Schwarz, Alfred WindfelderRequires cookie*
 Title    Abhängigkeit der Chlor-Isotopenseparation vom Vernetzungsgrad eines stark basischen Anionenaustauschers Dependence of Chlorine Isotope Separation on the Degree of Cross Linkage of a Strongly Basic Anion Exchange Resin  
 Abstract    Using ion exchange chromatography, the dependence of the chlorine isotope separation on the degree of cross linkage of a strongly basic anion exchange resin was investigated. With increasing degree of cross linkage the elementary separation effect for the two stable isotopes 35 C1 and 37 C1 increases. In all experiments 35 C1~ is enriched in the resin phase, whereas 37 C1~ is enriched in the solution, using 0.1 M NaNC>3 as an eluant. Within the degree of cross linkage of 2 to 10 per cent investigated, there is a linear correlation of the elementary separation effect of the chlorine isotopes with the selectivity coefficient between the ions NO3"" and Cl -. The results show that the electrolyte behavior of anionic isotope exchange reactions is comparable with that of cations. The 35 C1/ 37 C1 isotope ratio is determined using thermal ionization mass spectrometry. Untersuchungen von Isotopieeffekten bei hetero-genen Ionenaustauschreaktionen sind bereits bei einigen Kationen durchgeführt w T orden, wie z.B. 
  Reference    Z. Naturforsch. 34b, 406—411 (1979); eingegangen am 4. Dezember 1978 
  Published    1979 
  Keywords    Isotope Separation, Chlorine, Ion Exchange Chromatography, Mass Spectrometry 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0406.pdf 
 Identifier    ZNB-1979-34b-0406 
 Volume    34 
3Author    KlausK. Mayer, Ilona Matolović, Erich Fischer, Carl DjerassiRequires cookie*
 Title    Mass Spectrometric Investigations on Unsaturated Hydrocarbons: Halogen Migration in the Molecular Ions of Acetylenes and Alkenes  
  Reference    Z. Naturforsch. 34b, 1612—1614 (1979); eingegangen am 13. Juni 1979 
  Published    1979 
  Keywords    Mass Spectrometry, Halogen Migration, Simple Alkenes, Alkynes 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1612_n.pdf 
 Identifier    ZNB-1979-34b-1612_n 
 Volume    34