Constants of Stability of Cobalt(II) Complexes with Glycylglycinate Ions in Aqueous Acetone Solutions

Potentiometric titration is used to determine constants of stability of cobalt(II) glycylglycinate complexes at a temperature of 298 K and the ionic strength of 0.1 M solutions in aqueous acetone solutions. It is established that in contrast to aqueous solutions, cobalt(II) mono-glycylglycinates, bis-glycylglycinates, and tris-ligand complexes can all form in water–acetone mixtures. The stability of cobalt(II) complexes with glycylglycinate ions grows along with the concentration of acetone in a solution.