Ion-pair extraction of uranium(VI) using N-cinnamoyl-<i>o</i>-tolyl hydroxylamine in presence of tri-<i>n</i>-octyl phosphine oxide in chloroform and hexafluorophosphoric acid

Abstract

N-cinnamoyl-<em>o</em>-tolylbhydroxylamine (CT₀HA.HL) forms extractable binary complex with uranium. The extracted complex, UO₂L₂₍₀₎ when shaken with tri-n-octylphosphine oxide (TOPO R) in chloroform, is gradually back-extracted into aqueous phase due to formation of the cationic complex, UO₂LR ⁺. The gradual substitution has been followed spectrophotometrically by the decrease in absorbance of UO₂L₂₍₀₎ Uranium(VI) can be extracted into the chloroform phase by formation of ion-pair [UO₂LR ⁺.PF)₀ of UO₂LR ⁺ with the anion hexafluorophosphate. Extraction of the ion-pair complex is followed by enhanced absorbance values. The substitution constant. <em>K_a </em>and ion-pair constant, <em>K_I, </em>have been evaluated to be 0.075 and 2.05 x 10³ respectively.