Density functional theory predicts the barriers for radical fragmentation in solution

Edward D. Lorance, Kirstin Hendrickson, Ian Gould

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

(Chemical Equation Presented) N-Methoxypyridyl radicals formed by one-electron reduction of the corresponding cationic heterocycles undergo N-O bond cleavage. Experimental activation free energies for a series of these bond fragmentations are compared to corresponding barriers determined from electronic structure calculations. The DFT barriers agree well with those from experiment, being smaller than the latter values by an average value of ca. 1 kcal/mol, for rate constants varying over almost 3 orders of magnitude, or within ca. 3 kcal/mol over 8 orders of magnitude of rate constant. For a model compound, the B3PW91/6-31+G* hybrid density functional method is also found to be in good agreement with the MCSCF-MRMP2 method. One of the reactions is found by DFT to have no minimum for the reactant radical, consistent with a truly barrierless reaction.

Original languageEnglish (US)
Pages (from-to)2014-2020
Number of pages7
JournalJournal of Organic Chemistry
Volume70
Issue number6
DOIs
StatePublished - Mar 18 2005

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Discrete Fourier transforms
Density functional theory
Rate constants
Free energy
Electronic structure
Chemical activation
Electrons
Experiments

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Density functional theory predicts the barriers for radical fragmentation in solution. / Lorance, Edward D.; Hendrickson, Kirstin; Gould, Ian.

In: Journal of Organic Chemistry, Vol. 70, No. 6, 18.03.2005, p. 2014-2020.

Research output: Contribution to journalArticle

Lorance, Edward D. ; Hendrickson, Kirstin ; Gould, Ian. / Density functional theory predicts the barriers for radical fragmentation in solution. In: Journal of Organic Chemistry. 2005 ; Vol. 70, No. 6. pp. 2014-2020.
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