Solvent extraction equilibria and kinetics of gallium(III) with 2-thenoyltrifluoroacetone in the absence and presence of trioctylphosphine oxide in toluene

The rate acid equilibrium of solvent extraction of gallium(III) from aqueou s perchlorate solutions into toluene with 2-thenoyltrifluoroacetone (Htta) was measured in the absence and presence of trioctylphosphine oxide (TOPO). A synergistic enhancement of the extraction was found when TOPO was added. When a correction was made for the association of Htta and TOPO in the org anic phase which decreased their concentrations available for the extractio n, the extracted adducts was found to be in the form of Ga(tta)(3)(TOPO)(2) . The rate of extraction was not high and it was dependent on the second or der with respect to Htta and the inverse second order with respect to H+ in both the absence and the presence of TOPO. The rate was accelerated by add ition of TOPO; the enhancement of the rate was proportional to the TOPO con centration.