Estimation of formation constants of ternary Cu(II) complexes with mixed amino acid enantiomers based on ligand exchange by capillary electrophoresis

Based on the principle of ligand exchange, a new method for estimating the formation constants of ternary Cu(II) complexes with mixed amino acid enant iomers has been proposed by capillary electrophoresis. As examples, the for mation constants of four complexes, namely (L-OH-Pro)Cu(II)(D-Phe), (L-OH-P ro)Cu(II)(L-Phe), (L-OH-Pro)Cu(II)(D-Trp) and (L-OH-Pro)Cu(II) (L-Trp), wer e estimated by this method. The dependence of stability of complexes on the stereo-selectivity and the possibility of predicting the enantiomer migrat ion order from complex stability has been discussed.