Stability Constants of Kinetically Inert Ge(IV) Complexes in Aqueous Solution by Discontinuous Potentiometry: Hydroxycarboxylate, Aminocarboxylate and (Poly-)Amino(Poly-)Carboxylate Ligands

Abstract

This is an experimental study of the complex formation between aqueous Ge(IV) and organic ligands of the α- and β-hydroxycarboxylate, α- and β-aminocarboxylate and (poly-)amino(poly-)carboxylate types in aqueous solution at 25.0 °C. α-substituted ligands (such as α-amino acid anions and ligands of the EDTA-family) were found to give rise to kinetically inert systems, which must be studied by a discontinuous potentiometric titration technique (i.e., for each titration point, an individual solution is prepared and left to equilibrate for extended periods of time). β-substituted ligands formed much weaker complexes and their reactions were labile. Speciation diagrams are presented and discussed for all the studied systems.