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The question of cyclic versus acyclic ions: The structure of [C 10 H 12 ] + ˙ gas phase ions
Author(s) -
Dass Chhabil,
Gross Michael L.
Publication year - 1985
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.1210200109
Subject(s) - chemistry , isomerization , ion , ring (chemistry) , tetralin , dissociation (chemistry) , benzene , photochemistry , medicinal chemistry , catalysis , organic chemistry
The extent of isomerization of acyclic and cyclic gas phase radical cations of composition [C 10 H 12 ] + ˙ has been investigated by using collisionally activated dissociation spectroscopy. Both electron and charge exchange ionizaiton were employed to form the ions with various internal energies. The [C 10 H 12 ] + ˙ ions investigated consisted of ionized phenylbutenes, ring‐substituted methyl derivatives of allylbenzene and phenylpropene, 1‐methyl‐2‐isopropenylbenzene, benzylcyclopropane, phenylcyclobutane, tetralin and 1‐methylindan. The 1‐methylindan and tetralin radical cations are the most stable of the C 10 H 12 isomeric radical ions. The [C 10 H 12 ] + ˙ formed from acyclic olefins having the double bond in conjugation with the aromatic ring retain the initial structure to a significant extent. However, ions derived from olefins with the double bond out of conjugation with the benzene ring preferentially cyclize to stable five‐ and six‐membered cyclic ions. Ring opening of small‐ring cyclic ions, such as ionized benzylcyclopropane and phenylcyclobutane, occurs, followed by ring closure to the tetralin radical cation.