Evaluation of liquid-liquid partition coefficients of multidentate amines by scaled particle theory

For some aliphatic and aromatic bidentate amines, e.g., ethylenediamine derivatives, which were used in the synergistic extraction system, the liquid-liquid partition coefficients (P) were measured between benzene and water phases and discussed together with other aliphatic and aromatic multidentate amines by using the scaled particle theory (SPT). The contributions of three kinds of Gibbs energies, i.e., the cavity formation energy <((G)over bar (c) .)> the dispersion energy <((G)over bar (dis))> and hydrogen-bonding energy <((G)over bar (h))>, to the P values were successfully evaluated. The main factor to determine the P value was <(G)over bar (h)>(10-55 kJ/mol) in the aqueous phase, but the contributions of <(G)over bar (c)> (6-15 kJ/mol) and <(G)over bar (dis)> (6-28 kJ/mol) were not negligibly small.