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The mass spectrometric fragmentation of n ‐alkanes
Author(s) -
Lavanchy André,
Houriet Raymond,
Gäumann Tino
Publication year - 1979
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.1210140205
Subject(s) - chemistry , fragmentation (computing) , ion , alkyl , heptane , nonane , polyatomic ion , electron ionization , tetradecane , bond cleavage , radical ion , photochemistry , olefin fiber , medicinal chemistry , analytical chemistry (journal) , organic chemistry , ionization , computer science , catalysis , operating system , polymer
The fragmentation of n ‐hexane, n ‐nonane and n ‐tetradecane under electron impact has been investigated, using 13 C labelled compounds. The mechanism of the formation of the alkyl radical ions is quantitatively explained by using a method of calculation developed in an earlier publication for n ‐heptane. It is assumed that these ions are formed either by a direct C‐C bond cleaveage or by a secondary olefin loss from an alkyl radical ion. In the latter case the probability for a particular carbon to be lost in the neutral fragment is assumed to be random. The probability for a direct cleavage to an alkyl ion is about 80% for an ion containing at least half of the number of carbon atoms of the molecular ion and 15% for the smaller ions. The [MH] + ion seems to be a special case not yet clearly understood. Former results about the loss of methyl from the molecular ion are confirmed.