Three systems of gold(III) complexes in an aqueous solution (I = 0.05 M, 25°C) with slow equilibration were studied by capillary electrophoresis. It was shown on an example of mixed chloride–hydroxide complexes Au(OH)iCl4-i - that, despite close sizes and identical charges of the forms, the mixed forms can be separated if they are kinetically inert. For the equilibria AuCl4 −+ am = AuamCl2 + + 2Cl– and AuamCl2 + + am = + Auam2 3+ + 2Cl–, where am is ethylenediamine (en) and 1,3-diaminopropane (tn), the logarithmic constants were logK2 = 10.4 for en, and logK1 = 16.1 and logK2 = 12.0 for tn, which satisfactorily agrees with the spectrophotometric data. There was a considerable effect of side processes, insignificant under normal conditions.
- capillary electrophoresis
- gold(III) complexes