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  • Open Access

Structure and thermodynamics of nonaqueous solvation by integral equation theory

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Journal of Cheminformatics20124 (Suppl 1) :P6

  • Published:


  • Continuum Solvation
  • Continuum Solvation Model
  • Electronic Structure Theory
  • Hexafluorobenzene
  • Apolar Solvent

Electronic structure theory under the influence of apolar solvents suffers from substantial methodical difficulties since in this case the solvent-induced solute polarization originates mainly from specific directional interactions and higher electric multipoles. Continuum solvation models based on the dielectric solvent response such as the PCM approach ignore such interactions and can therefore not adequately model solvation effects in nonaqueous environments.

The “embedded cluster reference interaction site model” (EC-RISM) [1] retains the granularity of the solvent and represents a microscopically more detailed and therefore improved approach towards solvation modeling. EC-RISM is based on a self-consistent solution of solvent distribution functions described by a 3D integral equation theory and solute electronic structure by mapping the solvent charge distribution onto discrete, solute-embedding point charges. In aqueous solution EC-RISM theory is capable of calculating pKa shifts [1] and tautomer ratios relatively fast and with high accuracy [2].

Here we outline the strength of the integral equation model by studying benzene and hexafluorobenzene solutions. In particular, the thermodynamics of differential solvation is quantified for organic compounds dissolved in these media. Moreover, it is shown that the respective solvent structures around particular solutes differ strongly, possibly leading to changes in the thermodynamic stability scale of various isomers which are not reproduced by the PCM model.

Authors’ Affiliations

Technische Universität Dortmund, Dortmund, 44227, Germany


  1. Kloss T, Heil J, Kast SM: Quantum chemistry in solution by combining 3D integral equation theory with a cluster embedding approach. J Phys Chem B. 2008, 112: 4337-4343. 10.1021/jp710680m.View ArticleGoogle Scholar
  2. Kast SM, Heil J, Güssregen S, Schmidt KF: Prediction of tautomer ratios by embedded-cluster integral equation theory. J Comput.-Aided Mol Des. 2010, 24: 343-353. 10.1007/s10822-010-9340-x.View ArticleGoogle Scholar


© Frach et al; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.