TY  - JOUR
AU  - Ionova, G.
AU  - Ionov, S.
AU  - Rabbe, C.
AU  - Madic, C.
AU  - Guillaumont, R.
AU  - Modolo, G.
AU  - Krupa, J. C.
TI  - Mechanism of trivalent actinide/lanthanide separation using synergistic mixtures of di (chlorophenyl) dithiophosphinic acid and neutral o-bearing co-extractants
JO  - New journal of chemistry
VL  - 25
IS  - 3
SN  - 1144-0546
CY  - London
PB  - RSC
M1  - PreJuSER-46729
SP  - 491 - 501
PY  - 2001
N1  - Record converted from VDB: 12.11.2012
AB  - The mechanism of synergistic selective extraction of Am(III) over Eu(III) from aqueous nitric acid solutions using di(chlorophenyl)dithiophosphinic acid [(Cl Phi)(2)PSSH] and neutral O-bearing organophosphorus co-extractants (B) has been investigated. (Cl Phi)(2)PSSH forms weaker complexes with Am(III) than R2PSSH (where R = alkyl group). However, the Am(III)/(Cl Phi)(2)PSSH complexes are stronger than the corresponding Eu(III)/(Cl Phi)(2)PSSH complexes, although the difference is not as large as in the case of the corresponding complexes formed with R2PSSH. The donor properties of co-extractants are also discussed. Chemical shifts in the P-31 NMR spectra of the organophosphorus co-extractants correlate qualitatively with the extractability of Am(III) and Eu(III) in (Cl Phi)(2)PSSH + B synergistic mixtures. The synergistic effect determines the selectivity not only qualitatively but also quantitatively. The high selectivity observed using tri-2-ethylhexyl phosphate (T2EHP) is caused by a synergistic bonding effect for the Am(III) complex and an antagonistic effect for Eu(III).A donor-acceptor mechanism is shown to promote Am(III) extraction for almost all B co-extractants. A contribution of entropy terms for extracted Eu(III) extraction is assumed to be significant. Interatomic distances REu-S in the Eu(III) complexes are calculated.The softness of S-bearing extractants XYPSSH (with X and Y = R, RO or ClC6H4) is discussed from the point of view of the effective charge carried by the S atoms. The hardness of Eu(III) and Am(III) is evaluated.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000167327300026
DO  - DOI:10.1039/b006745h
UR  - https://juser.fz-juelich.de/record/46729
ER  -