Extraction of Plutonium(IV) with l-Phenyl-3-Methyl-4-Benzoyl Pyrazol-5-one and Tri-n-octylphosphine Oxide

Abstract

The synergistic extraction of plutonium(IV) with l-phenyl-3-methyl-4-benzoyl pyrazol-5-one (HPMBP) and tri-n-octylphosphine oxide (TOPO) has been investigated using toluene as the diluent and perchloric acid as the aqueous medium. Several species with the stoichiometry Pu(PMBP) 4 , Pu(PMBP) 4 · TOPO and PU(PMBP) 3 (C10 4 ) · 2TOPO are co-extracted into the organic phase. The relative proportion of these species depends on the Perchlorate concentration and on the concentration ratio of HPMBP to TOPO. The adduct formation constants for the ternary species for Pu 4+ are found to be smaller than those of UO| + and Am 3 + . Steric factors play a dominant role in the coordination of the neutral oxodonor.

Synergism as a phenomenon in solvent extraction of 4f-elements with calixarenes

“…TOPO, TBP, di-n-butyloctanamide, di-n-octyl sulfoxide, methylisobutylketone. [35][36][37][38]52,[97][98][99] It is known that the major factor in synergism is an increase in hydrophobic character of the extracted metal complex upon addition of the synergistic agent. So, the transformation of the self-adduct into mixed complex LnL 3 $S according to eqn (5) when 4-acylpyrazolones are applied cannot contribute to a large increase in its stability in the organic phase as both LnL 3 $HL and LnL 3 $S do not contain water molecules in the coordination sphere.…”