Etude du mécanisme de perte d'ethylène (propène) desN-ethyl (propyl) bromo-1,2,4-triazoles
Autor: | Robert Flammang, H. Mispreuve, André Maquestiau, Yves Van Haverbeke |
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Rok vydání: | 1977 |
Předmět: | |
Zdroj: | Organic Mass Spectrometry. 12:205-208 |
ISSN: | 1096-9888 0030-493X |
DOI: | 10.1002/oms.1210120405 |
Popis: | Le C-bromotriazole est genere en ses trois formes tautomeres par elimination d'ethylene a partir de composes N-ethyles et ces ions tautomeres conservent leur structure avant toute fragmentation ulterieure. L'analyse de spectres ‘MIKE’ et ‘CID’ montre que la perte d'ethylbne se deroule suivant un mecanisme non concerte avec un transfert d'hydrogene a quatre ou cinq centres. Les resultats montrent egalement que les 3-et 5-bromotriazoles contribuent au spectre de masse de l'heterocycle parent. La perte de propene de N-propylbromotriazoles est egalement discutee. C-bromo-1,2,4-trizole is generated in three different tautomeric forms by ethylene elimination from the N-ethyl compounds and these toutomes are shown to retain their structure prior to further fragmentation. The analysis of mass analysed ion kinetic energy and collision incuded dissociation spectra confrrms that ethylene loss proceeds by a tw-step mechanism with a five- (or four-) centred hydrogen transfer. The results show also that the 3- and 5-bromotriazole structures only are responsible for the mass spectrum of the parent heterocycle. Similar data are dicussed for the loss of propene from N-propylbromotriazoles. |
Databáze: | OpenAIRE |
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