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Gas phase reactivity of cation radicals and protonated species from isomeric C 4 H 8 S thioethers
Author(s) -
Paradisi C.,
Visentini A.,
Traldi P.
Publication year - 1989
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570260239
Subject(s) - chemistry , protonation , electron ionization , fragmentation (computing) , ion , dissociation (chemistry) , thioether , mass spectrometry , chemical ionization , tetrahydrothiophene , ionization , reactivity (psychology) , radical , metastability , photochemistry , analytical chemistry (journal) , medicinal chemistry , stereochemistry , organic chemistry , chromatography , computer science , medicine , alternative medicine , pathology , operating system
Four isomeric thioethers, 2,3‐dimethylthiirane ( 1 ), 2‐methylthietane ( 2 ), tetrahydrothiophene ( 3 ), and allyl methyl thioether ( 4 ), have been subjected to mass spectrometric analysis in the gas phase, under electron impact (El) and chemical ionization (CI) conditions. The metastable molecular ions M + ′ generated from 1‐4 under EI (70 eV) conditions give distinct patterns of unimolecular fragmentation, thus indicating that isomer interconversion reactions are slower than dissociation (a possible exception, to some extent, is the case of [M 2 ] + ′ and [M 2 ] + ′). The change of the relative intensities of some prominent peaks with increasing ion lifetime (decomposition within the ion source, the first, and the second field‐free regions of the mass spectrometer) is pointed out. Metastable [MH] + ions, generated from 1‐4 in chemical ionization experiments with CH 4 , all eliminate H 2 and H 2 S, although in different relative proportions. In addition to these processes protonated 4 also undergoes loss of C 2 H 4 and C 3 H 6 , likely from a C ‐protonated structure.