화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.56, No.6, 2830-2835, 2011
Complex Formation of the Cerium(IV) Ion with Glycyl-Glycine at Different Ionic Strengths
The protonation equilibria of glycyl-glycine and its complex formation with the cerium(IV) ion in aqueous solution were studied over a wide pH range (2 to 12) using a combination of potentiometric and spectrophotometric methods at constant temperature (25 degrees C) and different ionic strengths [(0.02, 0.05, 0.10, 0.15, 0.30, 0.50, 0.70, and 1.00) mol.dm(-3) sodium perchlorate]. Least-squares regression calculations are consistent with the formation of the CeL(3+) and CeHL(4+) species for the studied system, where L(-) represents the deprotonated peptide. The species concentrations were plotted at different pH values and were discussed. The dependence of the protonation of the ligand and the stability constant of the complex species on ionic strength is described by a Debye-Huckel type equation, and finally the results have been compared with the values reported previously and interpreted.