Application of group contribution models to the calculation of the octanol-water partition coefficient

A comprehensive review of the application of group contribution (GC) models such as various forms of UNIFAC and the AFC correlation model for P-ow (oc tanol-water partition coefficient) calculations has been carried out. UNIFA C is an activity coefficient model, while AFC is a model specific for P-ow calculations. Five different versions of UNIFAC and the AFC correlation mod el have been compared to each other and to experimental data. The range of applicability of the GC models to P-ow is discussed, and general conclusion s are obtained. A thorough analysis of the models was conducted including r esidual plots and numerical and graphical comparisons. We conclude that the GC concept has possibly exhausted its applicability to account for highly asymmetric systems, especially aqueous solutions with complex polyfunctiona l chemicals.