Theoretical prediction of partition coefficients via molecular electrostatic and electronic properties.

Previously published methods for calculation of Abraham's polarity/polarizability and hydrogen bond acidity and basicity descriptors are validated for their ability to predict the various partition coefficients of 80 challenging molecules. As well as this indirect validation, accurate log P predictions are shown to be possible by using directly the fundamental molecular properties used in the calculation of descriptors. From a general point of view, the van der Waals and hydrogen bond interactions present between the solute and the water/solvent system can be represented by charge-based interactions, which are partitioned into a positive and a negative term (Sigma(T)V(Max) and Sigma(T)V(Min)), dipole-based interactions (mu) and induced dipole-based interactions (alpha); further stabilization is possible if solute and solvent densities come into contact and overlap (Sigma(T)E). A discussion is opened on the possibility to extend this set to describe systems with electron donor/acceptor interactions other than hydrogen bonding.