Abstract: | (S,S)-N,N′ -Bis(aminoacyl)ethane- and (S,S)-N,N′ -bis(aminoacyl)propanediamines (AA-NN-2 and AA-NN-3, respectively, AA = alanine, phenylalanine, valine) were synthesized as the dihydrochlorides, and their complexes with Cu(II) studied potentiometrically. Since these ligands in the presence of Cu(II) are able to perform chiral resolution of D ,L -dansylamino acids in HPLC (reversed phase), in a certain pH range (6.5–8.5), it is important to know the equilibria existing between ligands and copper in aqueous solution. For AA-NN-2, four species, CuLH3+, CuL2+, Cu2L2H , and CuLH?2, were detected, whereas for AA-NN-3, only CuLH3+, CuL2+, and CuLH?2 were found. The aim is to find out which complexes may be involved in the recognition process. |