Polarography of mixed-ligand complexes of copper with some amino-acids and oxalate

Mixed-ligand complexes formed by copper(II) with an amino-acid (aspartic acid, glutamic acid or lysine) and oxalic acid have been investigated polarographically. These 1:1:1 complexes all undergo a two-electron reduction at the dropping mercury electrode. The stability constants computed from the shift in half-wave potential with changing ligand are discussed from the point of view of steric, electrostatic and statistical considerations.