ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Unimolecular decompositions of 2-methyl-1-hexene and several labelled analogues were studied following 70 eV electron impact (normal and metastable spectra) and field ionization (field ionization kinetic measurements). Molecules labelled with 13C in the 1-position and the methyl position were found to behave essentially identically. This is attributed to rapid transfer of a hydrogen atom mainly from C-5 to C-1 (γ-hydrogen shift). Loss of ethene, propene or propenyl do not involve loss of the methyl carbon or C-1. All three reactions are better than 90% specific in this respect under all conditions studied. At shorter times, C3H6 loss is the dominant reaction, while at longer times C2H6 loss accounts for 〉90% of the ion current. It is proposed that at least two distinct pathways for C2H4 loss operate in linear 1-alkenes, one of which (loss of carbons 1 and 2) is blocked by a 2-methyl substituent. The [C6H11]+· and [C5H10]+· ions formed from 13C labelled 2-methyl-1-hexenes fragment in an essentially statistical fashion.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210150903
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