Studies on Mixed Ligand Complexes of Th4+ with some Oxygen Donor Ligands

Abstract

The complexation reactions of Th⁴⁺ with oxygen donor ligands,
2-hydroxybenzoic acid (sa), 3-carboxy-4-hydroxybenzenesulphonic
acid (ss) and 1,2-dihydroxybenzene (ca) have been studied by pH-metric
methods. Formation constant values of the various binary,
hydroxo and ternary complexes including Th(sa)²⁺, Th(sa)₂,
Th(Sa)₃^2-,  Th(sa)₄^4-,  Th(sa)(OH)⁺, Th(ss)⁺, Th(ss)₂^2-,  Th(ss)₃^5-,
Th(ss)₄^8-,  Th(ss)(OH),  Th(ss)(OH)₂^-,  Th(ss)₂(OH)^3-, Th(ca)²⁺,
Th(ca)₂,  Th(ca)(OH)⁺,   Th(ca)(OH)₂,  Th(sa)(ss)^-,  Th(sa)(ca),
Th(ss)(ca)^- ,  Th(sa)(ss)₂^{4 -},  Th(ss)(sa)₂^3-,  Th(ca)(sa)₂^2- ,  Th(ca)(ss)₂^{4 -}
and Th(sa)₂(ss)₂^6-  liable to exist in mixtures containing corresponding
metal-ligand /pair of ligand ratio have been determined at
25°C and at an ionic strength of 0.1 M KNO₃ and the results have
been discussed.