Conformational dynamics of α,β,γ,δ-tetraarylporphyrins and their dications

Jennie Wang Dirks, George Underwood, Jolene Cox Matheson, Devens Gust

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Abstract

Rotational isomerism in several tetraarylporphyrin free bases and the corresponding dications has been studied by using dynamic 1H NMR spectroscopy. The average free energy of activation for rotation of a single aryl ring for the stereoisomers of α,β,γ,δ-tetrakis(2-methoxyphenyl)porphyrin is ΔG 433 = 25.9 kcal/mol. The barrier for the corresponding dication is ΔG388 = 23.0 kcal/mol. For α,β,γ,δ-tetrakis(2,4-dimethoxyphenyl)porphyrin and its dication, the rotational barriers are ΔG 433 = 25.2 and ΔG 388 = 21.8 kcal/mol, respectively. These results shed light on the questions of the degree of distortion of the porphyrin macrocycle in solution and the orientation of the aryl rings relative to the mean porphyrin plane.

Original languageEnglish (US)
Pages (from-to)2551-2555
Number of pages5
JournalJournal of Organic Chemistry
Volume44
Issue number14
StatePublished - 1979

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Porphyrins
Stereoisomerism
Nuclear magnetic resonance spectroscopy
Free energy
Chemical activation

ASJC Scopus subject areas

  • Organic Chemistry

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Dirks, J. W., Underwood, G., Matheson, J. C., & Gust, D. (1979). Conformational dynamics of α,β,γ,δ-tetraarylporphyrins and their dications. Journal of Organic Chemistry, 44(14), 2551-2555.

Conformational dynamics of α,β,γ,δ-tetraarylporphyrins and their dications. / Dirks, Jennie Wang; Underwood, George; Matheson, Jolene Cox; Gust, Devens.

In: Journal of Organic Chemistry, Vol. 44, No. 14, 1979, p. 2551-2555.

Research output: Contribution to journalArticle

Dirks, JW, Underwood, G, Matheson, JC & Gust, D 1979, 'Conformational dynamics of α,β,γ,δ-tetraarylporphyrins and their dications', Journal of Organic Chemistry, vol. 44, no. 14, pp. 2551-2555.
Dirks, Jennie Wang ; Underwood, George ; Matheson, Jolene Cox ; Gust, Devens. / Conformational dynamics of α,β,γ,δ-tetraarylporphyrins and their dications. In: Journal of Organic Chemistry. 1979 ; Vol. 44, No. 14. pp. 2551-2555.
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