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Isomeric [C,H 3 ,N,O] + ˙ ions and their neutral counterparts
Author(s) -
Hop Cornelis E. C. A.,
Chen Hongwen,
Ruttink P. J. A.,
Holmes John L.
Publication year - 1991
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210260803
Subject(s) - isomerization , ion , chemistry , dissociation (chemistry) , fragmentation (computing) , metastability , ab initio , mass spectrometry , hydrogen , mass spectrum , analytical chemistry (journal) , catalysis , organic chemistry , chromatography , computer science , operating system , biochemistry
The isomeric ions [H 2 NC(H)O] + ˙, [H 2 NCOH] + ˙, [H 3 CNO] + ˙ and [H 2 CNOH] + ˙ were examined in the gas phase by mass spectrometry. Ab initio molecular orbital theory was used to calculate the relative stabilities of [H 2 NC(H)O] + ˙, [H 2 NCOH] + ˙, [H 3 NCO] + ˙ and their neutral counterparts. Theory predicted [H 2 NC(H)O] + ˙ to be the most stable ion. [H 2 NCOH] + ˙ ions were generated via a 1,4‐hydrogen transfer in [H 2 NC(O)OCH 3 ] + ˙, [H 2 NC(O)C(O)OH] + ˙ and [H 2 NC(O)CH 2 CH 3 ] + ˙. Its metastable dissociation takes place via [H 3 NCO] + ˙ with the isomerization as the rate‐determining step. [H 2 CNOH] + ˙ undergoes a rate‐determining isomerization into [H 3 CNO] + ˙ prior to metastable fragmentation. Neutralization‐reionization mass spectrometry was used to identify the neutral counterparts of these [H 3 ,C,N,O] + ˙ ions as stable species in the gas phase. The ion [H 3 NCO] + ˙ was not independently generated in these experiments; its neutral counterpart was predicted by theory to be only weakly bound.