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FIGURE 2 Hydrogen-bond dissociation energy of a protonated carboxylic group (butyric acid) interacting with a methanol molecule. The hydrogen-bond dissociation energies were calculated at selected bond lengths using B3LYP/6-311+G(2d,p) (see Methods for details) for HO–C=O (
), HO–C=O (
), and HO–C=O (
). The curves are the results of nonlinear least-square fitting of the computational data to Morse potentials. The strongest hydrogen-bonding interaction occurs at 2.94 Å with –11.6 kJ/mol for HO–C=O, 2.87 Å with –18.8 kJ/mol for HO–C=O, and 2.75 Å with –32.1 kJ/mol for HO–C=O.
Copyright © 2008 by the Biophysical Society.
