The diastereoisomeric salt pair formed between α-phenyl-ethyl-amine and R-1-phenylethylsuccinamic acid were investigated by
physico-chemical methods. Melting and solubility phase diagrams were determined, the coincidence of the eutectic points of
the two phase diagrams were demonstrated. The large difference in physico-chemical properties of the salt pair explains the
efficient enantiomer separation.