ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Metastable peak characteristics, ionization and appearance energy data and isotopic labelling experiments have been applied to a study of the fragmentation behaviour of the molecular ions of the isomeric C4H6O2C acids, cis and trans-crotonic acids, methacrylic acid, butenoic acid and cyclopropane carboxylic acid. Prior to the losses of H2O and CH3, all the metastable molecular ions rearrange to [cis-crotonic acid]+⋅ ions. Loss of H2O, which generates a composite metastable peak, is proposed to yield vinylketene and/or cyclobutenone molecular ions. Detailed mechanisms are presented for the isomerizations of the various molecular ions and for the above fragmentations. Ionized 3-butenoic and cyclopropane carboxylic acids display a major loss of CO from their metastable ions, a minor process in the other isomers. The metastable peaks consist of two components and these are ascribed to the formation of propen-1-ol and allyl alcohol as daughter ions. Some comparative data are presented for the isomeric C5H8O2 acids, tiglic acid, angelic acid and senecioic acid.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210140409
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