Thorium Complexation with Aliphatic and Aromatic Hydroxycarboxylates: A Combined Experimental and Theoretical Study.

Autor: Kumar P; Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India., Dumpala RMR; Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.; Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe, Germany., Telmore VM; Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India., Sadhu B; Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India., Sundararajan M; Theoretical Chemistry Section, Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India., Yadav AK; Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India., Bhattacharyya D; Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India., George JP; Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Jazyk: angličtina
Zdroj: ACS omega [ACS Omega] 2024 Jun 13; Vol. 9 (25), pp. 27289-27299. Date of Electronic Publication: 2024 Jun 13 (Print Publication: 2024).
DOI: 10.1021/acsomega.4c01581
Abstrakt: Hydroxycarboxylic acids, viz., α-hydroxyisobutyric acid (HIBA) and mandelic acid (MA), have been widely employed as eluents for inner transition metal separation studies. Both extractants have identical functional groups (OH and COOH) with different side-chains. Despite their similarities in binding motifs, they show different retention behaviors for thorium and uranium in liquid chromatography. To understand the mechanism behind the trend, a detailed study on the aqueous phase interaction of thorium with both extractants is carried out by speciation, spectroscopy, and density functional theory-based calculations. Potentiometric titration experiments are carried out to reveal the stability and species formed. Electrospray ionization mass spectrometry is performed to identify the formation of different species by Th with both HIBA and MA. It is seen that for Th-HIBA and Th-MA, the dominating species are ML 3 and ML 4 , respectively. A similar pattern observed in potentiometric speciation analysis supports the tendency of Th to form higher stoichiometric species with MA than with HIBA. The difference in the dominating species thus helps in explaining the reversal in the retention behavior of uranium and thorium in the reverse-phase liquid chromatographic separation. The results obtained are corroborated with extended X-ray absorption fine structure spectroscopic measurements and density functional theory (DFT) calculations.
Competing Interests: The authors declare no competing financial interest.
(© 2024 American Chemical Society.)
Databáze: MEDLINE
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