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Author Frøsig, Lars ♦ Tureček, František
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©1998
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences
Subject Keyword Analytical Chemistry ♦ Biotechnology ♦ Organic Chemistry ♦ Proteomics ♦ Bioinformatics
Abstract Neutralization-reionization mass spectrometry was used to generate hypervalent radicals pyrrolidinium (1H $^{·}$), N-methylpyrrolidinium (2H $^{·}$), N-ethylpyrrolidinium (3H $^{·}$), N-phenylpyrrolidinium (4H $^{·}$), N,N-dimethylpyrrolidinium (5$^{·}$), N-methyl-N-ethylpyrrolidinium (6 $^{·}$), and their deuterium-labeled derivatives and to study their dissociations in the gas phase. Isotopomers of pyrrolidinium and N-phenylpyrrolidinium showed small fractions of stable radicals of microsecond lifetimes that were detected following collisional reionization. The leaving group abilities in radical dissociations were established as H$^{·}$ » C$_{2}$H$_{5}$ $^{·}$ ≈ C$_{6}$H$_{5}$ $^{·}$> CH$_{3}$ $^{·}$. The hydrogen atom was the best leaving group in secondary and tertiary pyrrolidinium radicals 1H $^{·}$–4H$^{·}$, whereas losses of ethyl, phenyl, and ring openings by N-C bond cleavages were less facile. Methyl was the worst leaving group among those studied. Ring cleavages dominated the dissociations of quaternary pyrrolidinium radicals 5$^{·}$ and 6$^{·}$, whereas losses of alkyl substituents were less efficient. The electronic properties of hypervalent ammonium radicals are discussed to rationalize the experimental leaving group abilities of hydrogen atom, alkyl, and phenyl radicals.
ISSN 10440305
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1998-01-01
Publisher Institution The American Society for Mass Spectrometry
Publisher Place New York
e-ISSN 18791123
Journal Journal of The American Society for Mass Spectrometry
Volume Number 9
Issue Number 3
Page Count 13
Starting Page 242
Ending Page 254

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Source: SpringerLink