Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Assignment of complex species by affinity capillary electrophoresis: The case of Th(IV)‐desferrioxamine B

Abstract : The electrophoretic mobility change of desferrioxamine B (DFO) was monitored by UV absorption spectrophotometry upon increasing the thorium(IV) concentration in the background electrolyte at two acidities ([HClO4]Tot = 0.0316 and 0.0100 M). These data enabled to assess the speciation model and to determine the equilibrium constant of [Th(DFO)H2]3+ at fixed ionic strength (I = 0.1 M (H,Na)ClO4). Affinity capillary electrophoresis (ACE) turned out to be most helpful in identifying the complexed species by ascertaining its charge and protonation state. The assignment of the correct stoichiometry relied on the reliable estimation of the electrophoretic mobility by assuming similar hydrodynamic radii for (DFO)H4+ and the chelate. The value of the apparent equilibrium constant (log 112 = 38.7 ± 0.4) obtained by ACE compares favorably well with those reported in the literature for thorium and a range of other metal ions, according to a linear free-energy relationship. This method is useful for studying metal-ligand binding equilibria and provides valuable information for further modelling the behavior of tetravalent actinides under environmental conditions. Structural information about the prevalent solution species in acidic conditions was gained by DFT calculations, confirming the bishydroxamato coordination mode of Th4+ by the diprotonated ligand.
Type de document :
Article dans une revue
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-02988507
Contributeur : Michel Meyer <>
Soumis le : vendredi 27 novembre 2020 - 17:31:30
Dernière modification le : vendredi 18 décembre 2020 - 15:42:02

Fichier

 Accès restreint
Fichier visible le : 2021-01-31

Connectez-vous pour demander l'accès au fichier

Identifiants

Citation

Vladimir Sladkov, Jérôme Roques, Michel Meyer. Assignment of complex species by affinity capillary electrophoresis: The case of Th(IV)‐desferrioxamine B. Electrophoresis, Wiley-VCH Verlag, 2020, 41 (21-22), pp.1870 - 1877. ⟨10.1002/elps.202000114⟩. ⟨hal-02988507⟩

Partager

Métriques

Consultations de la notice

67