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  • Analytical Chemistry and Spectroscopy  (2)
  • 1
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectrometry of perfluoro compounds (F-alkyl compounds) has seldom been the subject of systematic studies. Fluorocarbons excepted, only a few mass spectra of such compounds have been analysed and corresponding fragmentations correlated. In this paper we report the mass spectra of 19 amides of perfluoro acids (RFCONHR) with R=benzyl, 2-phenylethyl, 2-phenylpropyl, 3-phenylpropyl, 2-(N-phenylamino)ethyl, and RF=F-methyl, n-perfluoropropyl, n-perfluoropentyl and n-perfluoroheptyl. These compounds exhibit quite different behaviour from their hydrocarbon homologues under electron impact (for instance no [RFCO]+ fragment was found). Specific deuterium labelling and high resolution measurements have been used to show typical rearrangements and to establish the fragmentation routes.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: In this paper, the behaviour of ethers, sulfides, selenoethers, amines, germanes and stannanes, substituted on the β-C by a methoxycarbonyl, methyl ketone, or cyano group is compared and discussed. The compounds containing group VB or VIB element are quite stable, while those with a group IVB element fragment very easily. Fragmentation α to the heteroatom gives peaks for which the intensity increases with the size of the element:[PhO]+〈[PhS]+〈[PhSe]+〈[Ph3Ge]+〈[Ph3Sn]+. Fragmentation at the β position gives very important peaks when the ionization potential is low or when the substituents inductive effect is strong (CN〈CO2CH3〈COCH3).
    Notes: Nous comparons et discutons dans ce travail les résultats obtenus lors de la fragmentation d'éthers, sulfures, sélénoéthers, amines, germanes et stannanes fonctionalisés en β par un groupement méthoxycarbonyle, méthylcétone ou nitrile. Les divers composés possédant un élément de la colonne VB et VIB du tableau périodique sont relativement stables sous l'impact électronique, alors que ceux de la colonne IVB se fragmentent très facilement. Les ruptures en α de l'hétéroatome donnent des pics dont l'intensité augmente avec la taille de celui-ci: [PhO]+〈[PhS]+〈[PhSe]+〈[Ph3Ge]+〈[Ph3Sn]+. La rupture en β conduit à des fragments d'autant plus intenses que le groupement fonctionnel a un potentiel d'ionisation plus faible ou un effet inductif plus fort (CN〈CO2CH3〈COCH3).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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