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Determination of reactivity by MO theory. 27. Molecular orbital study of the gas‐phase decarboxylation of but‐3‐enoic acid
Author(s) -
Lee Ikchoon,
Cho Jeoung Ki,
Lee BonSu
Publication year - 1984
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540050302
Subject(s) - decarboxylation , gas phase , chemistry , reactivity (psychology) , computational chemistry , molecular orbital theory , phase (matter) , molecular orbital , medicinal chemistry , organic chemistry , molecule , catalysis , medicine , alternative medicine , pathology
The MINDO /3 calculations were performed on the potential energy profile involved in the equilibrium\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} {\rm crotonic acid \rightleftharpoons isocrotonic acid \rightleftharpoons but-3-enoic acid} \\ {\rm (III)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(II)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(I)} \\ {\rm } \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\to {\rm propene + CO}_{\rm 2} \\ \end{array} $$\end{document}Optimized structures of stable molecules and transition states have been determined; thermodynamic stabilities of pure acids and barriers indicated that the equilibrium can be set up from any acids. It was argued that direct decarboxylation is only conceivable from (I), since in this process a 1, 5‐hydrogen shift is involved, whereas a higher barrier process of 1, 3‐hydrogen shift is required in direct decarboxylations from other acids. Direct interconversion of (I) and (III) was found to be unfavorable due to a high barrier involved.