Formation and identification of ionized and neutral cumulenes, RNCCCNH, by tandem mass spectrometry

0. Metastable ion fragmentations (unimolecular and collision induced) and deuterium-labelling experiments are in agreement with the formation of a cumulenic structure, HN=C=C=C=NH (3a+.). The hitherto unreported molecules HNCCCNH are also shown to be stable when formed in the low-pressure gas phase of the mass spectrometer by using the technique of neutralization-reionization mass spectrometry. The arguments developed for the characterization of 3a+. have also been extended to the methylated and phenylated analogues 3b+. and 3c+. [RN=C=C=C=NH+., R = CH3 or C6H5]. On flash-vacuum pyrolysis at 700-degrees-C, 1 also loses HN=C=O producing the cumulene 3a, which is in turn readily tautomerized into malononitrile via wall collisions. -->
ISSN: 1096-9888
0030-493X
DOI: 10.1002/oms.1210281030
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_________::b1363066bc12f75b311e6d4b1609f6ac
https://doi.org/10.1002/oms.1210281030
Rights: CLOSED
Přírůstkové číslo: edsair.doi...........b1363066bc12f75b311e6d4b1609f6ac
Autor: Sophie Laurent, M. Flammang-Barbieux, Robert Flammang, Curt Wentrup
Rok vydání: 1993
Předmět:
Zdroj: Organic Mass Spectrometry. 28:1161-1166
ISSN: 1096-9888
0030-493X
DOI: 10.1002/oms.1210281030
Popis: Using a combination of mass spectrometric techniques, it is shown that 5-amino-4-cyanoisoxazole molecular ions (1+.), lose isocyanic acid HNC=O, not fulminic acid, HC=N --> 0. Metastable ion fragmentations (unimolecular and collision induced) and deuterium-labelling experiments are in agreement with the formation of a cumulenic structure, HN=C=C=C=NH (3a+.). The hitherto unreported molecules HNCCCNH are also shown to be stable when formed in the low-pressure gas phase of the mass spectrometer by using the technique of neutralization-reionization mass spectrometry. The arguments developed for the characterization of 3a+. have also been extended to the methylated and phenylated analogues 3b+. and 3c+. [RN=C=C=C=NH+., R = CH3 or C6H5]. On flash-vacuum pyrolysis at 700-degrees-C, 1 also loses HN=C=O producing the cumulene 3a, which is in turn readily tautomerized into malononitrile via wall collisions.
Databáze: OpenAIRE
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