Potentiometric and spectral studies of complex formation of La(III), Pr(III) and Lu(III) with aspartic acid and asparagine

摘要

The composition and stability of La3+, Pr3+and Lu3+complexes with aspartic acid and asparagine were analysed. The formation of complexes of the typeMLandMHLwas determined for La3+and Pr3+with aspartic acid, and of the typeMHLfor Lu3+with aspartic acid. For La3+, Pr3+and Lu3+with asparagine the formation ofML(OH) complexes was observed. By means of1H NMR and13C NMR studies the participation in the coordination of both -COOH groups was determined for aspartic acid, whereas for asparagine the participation of the -COOH group was determined in complexes with La3+, Pr3+, and of the -COOH and the -NH2groups in the complex with Lu3+.