Thio-β-diketonates of lanthanides-III synergistic solvent extraction behavior of neodymium(III) with 1,1,1-trifluoro-4(2-thienyl)-4-mercaptobut-3-en-2-one (HSTTA) and some neutral donors

Abstract

The synergistic solvent extraction behavior of Nd(III) with HSTTA and the neutral donors dipyridyl, tributylphosphate (TBP) and tri-n-octylphosphine oxide (TOPO) (≡L) have been investigated using benzene as the organic solvent and an ionic strength 0.1 (NaClO₄). The extraction process is governed by the following reaction equilibrium Nd³+3HSTTA_(O)+nL_(O)⇔Nd(STTA)³(L)^n(O)+3H⁺ The extraction constants (K_3,n) and the adduct formation constants (β_3,n) have been evaluated. With dipyridyl, only mono adduct formation takes place, whereas, with TBP and TOPO, both mono and bis adducts are formed. The β_3,n values for HSTTA systems are higher than for the corresponding HTTA systems.