Formation of Mixed Ligand Complexes of UO Involving Some Nitrogen and Oxygen Donor Ligands

Abstract

The complexation reactions of UO₂²⁺ ion with nitrogen and oxygen
donor ligands, 1-amino-2-naphthol-4-sulphonic acid, o-aminophenol (ap),
2-hydroxybenzoic acid (sa), 3-carboxy-4-hydroxybenzenesulphonic acid
(ss) and 1,2-dihydroxybenzene (ca) have been investigated in aqueous
solution employing the pH-titration technique. Aanalysis of the experimental
data recorded at 25°C and at an ionic strength of 0.10 M KNO₃ indicates
formation of binary, hydroxo and ternary complexes including UO₂(an),
UO₂(an)₂^2-, UO₂(an)(OH)^-,  UO₂(ap)⁺,  UO₂(ap)₂,  UO₂(sa),  UO₂(sa)₂^2-,
UO₂(sa)(OH)^-,  UO₂(sa₂)(OH)^3-,  UO₂(ss),  UO(ss)₂^{4 -},  UO(ss)(OH)^2-,
UO₂(ss₂)(OH)^5-,  UO₂(ca),  UO₂(ca)₂^2-,  UO₂(ca)(OH)^-,  UO₂(an)(ap)^-,
UO²(an)(sa)^2-,  UO₂(an)(ss)^3-,  UO₂(an)(ca)^2-,  UO₂(ap)(sa)^-,
UO₂(ap)(ss)^2-,  UO₂(ap)(ca)^-,  UO₂(sa)(ss)^3-,  UO₂(sa)(ca)^2-, and
UO₂(ss)(ca)^3- in mixtures containing corresponding metal-ligand pair of
ligand ratio. Formation constant values of the existing species have been
evaluated and the results have been discussed.