Mechanism of Trivalent Actinide/Lanthanide Separation Using Bis(2,4,4-Trimethylpentyl) Dithiophosphinic Acid (Cyanex 301) and Neutral O-Bearing Co-Extractant Synergistic Mixtures

Separation of Am(III) and Cm(III) from trivalent lanthanides by 2,6-bistriazinylpyridine extraction chromatography for radioactive waste management

“…The mechanism for the soft donor ligands containing nitrogen or sulfur to exhibit a significantly higher adsorption for trivalent actinides over lanthanides has not yet been clarified. A recent study on a S-bearing ligand (Cyanex 301) indicated that the strong coordination of trivalent metals to S atom would be caused by a covalent effect that is significantly greater for Am(III)-S than for Ln(III)-S bonds [9]. Fig.…”

Adsorption of lanthanides(III) from aqueous solutions by fullerene black modified with di(2-ethylhexyl)phosphoric acid

“…The high complexing power of TPMDPO is apparently due to its bidentate coordination in the resulting complexes [17]. Earlier, a similar synergistic effect was observed in the solvent extraction of Eu(III) and Am(III) with a mixture of octyl(phenyl)-N,N-diisobu tylcarbamoylmethylphosphine oxide (CMPO) and bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HR) [18] or di(chlorophenyl)dithiophosphinic acid [19]. It was shown that Eu(III) passes into the organic phase as an Eu(NO 3 )R 2 (CMPO) 3-x (H 2 O) x complex [18].…”

“…Earlier, a similar synergistic effect was observed in the solvent extraction of Eu(III) and Am(III) with a mixture of octyl(phenyl)-N,N-diisobu tylcarbamoylmethylphosphine oxide (CMPO) and bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HR) [18] or di(chlorophenyl)dithiophosphinic acid [19]. It was shown that Eu(III) passes into the organic phase as an Eu(NO 3 )R 2 (CMPO) 3-x (H 2 O) x complex [18]. Complexes of similar composition would probably result when Ln ions are adsorbed from nitric acid solutions by the FB sorbent impregnated with a mixture of HA and TPMDPO.…”

Mechanism of trivalent actinide/lanthanide separation using synergistic mixtures of di(chlorophenyl)dithiophosphinic acid and neutral O-bearing co-extractants

“…In ref. 8, it was shown that the mechanism of Am(III) and Eu(III) extraction by with a hard (O) atom co-R 2 PSSH extractant B is mainly governed by the change in the nature of the MÈS bond owing to the transfer of electron density in the system O % M % S : the hard O atom controls the donor properties of the S atoms in the acidic S-bearing extractant.…”