Substitution reactions of several lead(II)-polyamine-N-polyacetate complexes with indium(III) in aqueous solutions

The kinetics of the substitution reactions of the lead(II) complexes of EDTA, EDTA.OH, CyDTA, and DTPA with the indium(III) ion have been studied in the pH range from 1.8 to 4.8 at 200C and at an ionic strength of 0.1 in the presence of an excess of lead(II) ions. The reaction for the CyDTA system seems to proceed through only the dissociative process, while those for the EDTA, EDTA.OH, and DTPA systems proceed through both the steps forming a binuclear intermediate and the dissociative steps, in which the reactions forming indium complexes proceed mainly through the paths involving InOH2+. (auth.)