Solvent-H2O mutual solubility effects in the synergic extraction of Ce3+

The mutual H2O-solvent solubility effect on the extraction of Ce3+ from an aqueous phase of 0.1 M ionic strength with thenoyltrifluoroacetone (HTTA), in seven different solvents and with a mixture of HTTA + trioctylphosphineoxide (TOPO) in the same solvents is studied. It is found that the synergistic adduct formation constant decreases as the mole fraction of the water dissolved in the solvent increases. An explanation to this observations is based on equilibrium considerations of the H2O existing in the coordination sphere of the metal in the adduct and that in the bulk organic phase. (orig.)