Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-I1-012-43
Acknowledgements: This work was partially supported by Award No. KUK-I1-012-43 made by King Abdullah University of Science and Technology (KAUST). G.C. acknowledges financial support from Science Foundations of Ireland (SFI) through the PI Grant 08/IN.1/11869. L.G. acknowledges funding provided by the European Research Council project n. 240624 and computer resources from CASPUR grant no. std09-332.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.