Synergistic solvent extraction studies of uranium(VI) using a combination of naphthenic acid and various neutral donors into benzene

Mohanty, I.; Murlidhar, J.; Chakravortty, V.

doi:10.1007/bf02386439

Cited by 8 publications

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References 12 publications

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“…To date, synergism was mainly attributed to the formation of mixed metallic complexes with the participation of all extractant molecules. For classical acidic extractant systems, the most common mechanisms propose the addition of neutral donor ligand to the acidic extractant. − ,,, However, in the literature most of the studies rely on experimental determination of the mixed species stoichiometry from the analysis of the metal ion distribution ratio for various experimental factors. This approach results from macroscopic data of extraction and does not take into account molecular interactions between the ligands and the cations or the extractants self-assembling properties.…”

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confidence: 99%

Synergism in a HDEHP/TOPO Liquid–Liquid Extraction System: An Intrinsic Ligands Property?

et al. 2016

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Among the proposed mechanisms to predict and understand synergism in solvent extraction, the possibility of a preorganization of the mixture of extractant molecules has never been considered. Whether involving synergistic aggregation as for solubilization enhancement with reverse micelles or favored molecular interaction between the extractant molecules, evaluation of this hypothesis requires characterization of the aggregates formed by the extractant molecules at different scales. We investigate here the HDEHP/TOPO couple of extractant with methods ranging from vibrational spectroscopy and ESI-MS spectrometry to vapor pressure osmometry and neutron and X-ray scattering to cover both molecular and supramolecular scales. These experimental methods are subjected to DFT calculations and molecular dynamics calculations, allowing a rationalization of the results through the different scales. Performed in the absence of any cation, this original study allows a decorrelation of the mechanisms at the origin of synergy: it appears that no clear preorganization of the extractants can explain the synergy and therefore that the synergistic aggregation observed in the presence of cations is rather due to the chelation mechanisms than to intrinsic properties of the extractant molecules.

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