ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The unstable neutral enol, 1-buten-3-yn-2-ol, and its deuterium-labelled analogues were generated in the gas phase by high-vacuum flash pyrolysis of the corresponding 2-exo-ethynylnorborn-5-en-2-ols, or alternatively from 1-ethynylcyclobutanol. The ionization energy of the enol was measured as 8.92 ± 0.03 eV. The cation radical (HC≡C(OH)=CH2)+· was prepared by electron-impact ionization of the neutral enol, or by dissociative ionization of 1-hexyn-3-ol and 1-ethynylcyclobutanol, and its heat of formation was determined as 944 kJ·mol-1. The heat of formation of the neutral enol was assessed as 83 ± 7 kJ·mol-1 in good agreement with MNDO calculations. Cation radicals HC≡C—C(OH)=CH2+· undergo four main unimolecular fragmentations due to losses of the OH H-atom, a CH3 group incorporating the C(1) methylene and the OH H-atom, CO, and H2O. The structure of the neutral enol and the mechanisms of the ionic decompositions are discussed.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19860690319
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