ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The gas-phase thermal decomposition of 5-ethyl-1-pyrroline has been studied in the temperature range 721-786 K. The decomposition appears to proceed by two pathways, one a radical route yielding pyrrole, ethylene and ethane as major products, and the other a molecular hydrogen elimination to form initially 2-ethyl-3H-pyrrole which rapidly rearranges to other ethylpyrroles via a series of 1,5-hydrogen shifts. Approximate rate constants for the unimolecular hydrogen elimination have been calculated and fit the Arrhenius relationship: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log (k/{\rm s}^{- 1}) = 12.5 \pm 0.4 - (55.5 \pm 1.4{\rm\,kcal\,mol}^{- 1})/\Theta {\rm\,where}\,\Theta = 2.303{\rm}RT. $$\end{document}Approximate calculations based on the radical pathway yield a value of ∼14 kcal mol-1 for the stabilization energy in the 1-pyrrolin-5-yl radical, in good agreement with that reported earlier for the substituted 2-aza-allyl radical.
Zusätzliches Material:
2 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19720550244
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