Thermodynamics of the Formation of Cu2+-Glycyl-Glycyl-Glycine Complex in Water-Ethanol Solutions at 298 K

摘要

The stability constants of monoligand complexes of copper(II) ions with glycyl-glycyl-glycine zwitterions ( triglycine, HL +/-) and triglycinate ions ( L-) in a water-ethanol solvent with 0.0, 0.1, 0.3, and 0.5 mole fractions of ethanol at an ionic strength of 0.1 created by sodium perchlorate and temperature T = 298.15 K are determined by means of potentiometric titration. It is found that an increase of ethanol content improves the stability of the investigated complexes, due mainly to the resolvation of ligands.