A potentiometric study on the complexation of Ag(I) with various N-methyl and C-methyl substituted ethylenediamines in 1-M NO3-

Abstract

The complexation of Ag(I) with five different N-methyl substituted, two C-methyl substituted ethylenediamines and ethylenediamine itself is studied using potentiometric pH and pAg measurements in 1 M KNO3 at 25.0-degrees-C. Mononuclear complexes, polynuclear complexes and their protonated forms are detected and the respective stability constants are tabulated. The stability constant of a given species generally decreases as the methylation increases on the terminal amino groups probably due to an increased steric hindrance. The number of species also decreases as the methylation increases. The stability constants of the ethylenediamines are also compared with previously determined stability constants of Ag(I)-propylenediamine complexes and some relationships are identified.