Effects of Charge and Intramolecular Structure on the Lipophilicity of Nitrophenols

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• 作者：Vé ; ronique Chopineaux-Courtois ; Fré ; dé ; ric Reymond ; Gé ; raldine Bouchard ; Pierre-Alain Carrupt ; Bernard Testa ; and Hubert H. Girault
• 刊名：Journal of the American Chemical Society
• 出版年：1999
• 出版时间：March 3, 1999
• 年：1999
• 卷：121
• 期：8
• 页码：1743 - 1747
• 全文大小：127K
• 年卷期：v.121,no.8(March 3, 1999)
• ISSN：1520-5126

文摘

The lipophilicity of a series of phenolic compounds was studied in the 1,2-dichloroethane (1,2-DCE)/water system. Cyclic voltammetry at the ITIES was used to study the transfer characteristics of thecharged species, and their partition coefficient was deduced from their formal transfer potential. For the neutralspecies, log P_DCE values were measured by a two-phase pH-metric method. The results are compared to thosepreviously obtained in octanol/water and by linear solvation energy relationships (LSER) in the two solventsystems. It is shown that nitrophenols with intramolecular H-bonding deviate from the solvatochromic equationfor the 1,2-DCE/water system, and discrepancies between both approaches are discussed on the basis ofconformational and steric effects. When charged however, all the species have approximately the same partitioncoefficients because the effect of the intramolecular H-bond disappears and the differences in measuredlipophilicity arise from the variation of the intramolecular charge delocalization due to resonance equilibria.Some biological implications of these properties are discussed.