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Updated: Jun 2, 2026
Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Anion-π interactions influence pK(a) values
Christopher J Cadman1, Anna K Croft
1School of Chemistry, University of Wales Bangor, Bangor, Gwynedd, LL57 2UW, United Kingdom. Tel: +44 1248 382 375.
Abstract:
Five 8-(4-R-phenyl)-1-naphthol derivatives were prepared by PdCl(2)-catalysed electrophilic aromatic substitution. The pK(a)' values for these 1,8-disubstituted arene naphthols have been measured in acetonitrile/water (R = NO(2), 8.42; R = Cl, 8.52; R = H, 8.56; R = Me 8.68; and R = OMe, 8.71) and indicate a correlation with the electronic nature of the arene substituent, as determined through LFER analysis. Contributions to the relative pK(a)' values have been interpreted, using M06-2X DFT calculations, as consisting of two components: A small contribution from initial OH-π bonding in the starting materials and a larger contribution from anion-π interactions in the products. Such effects have implications for a range of other systems.
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