Water Soluble PDCA Derivatives for Selective Ln(III)/An(III) and Am(III)/Cm(III) Separation

Abstract

The synthesis and solvent extraction behavior of dipicolinic acid (pyridine-2,6-dicarboxylic acid, PDCA) and their derivatives have been studied for possible use in selective back-extraction of actinides, especially americium. The extraction was performed from an organic phase containing a mixture of trivalent actinides and lanthanides pre-extracted with N,N,N’,N’-tetraoctyl diglycolamide (TODGA). The efficiency of the back-extraction was enhanced when the picolinate platform was used in a heterocyclic decadentate ligand called h4tpaen. Beyond selective An/Ln extraction, the aqueous soluble h4tpaen ligand seemed a potential reagent for an intra-group Am(III)/Cm(III) separation with a separation factor SFCm/Am of about 3.5.