Mechanism of transformation of Np(V) into Np(IV) in sodium 1,2-cyclohexanediaminetetraacetate solutions
- Authors: Shilov V.P.1, Fedoseev A.M.1
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Affiliations:
- Frumkin Institute of Physical Chemistry and Electrochemistry
- Issue: Vol 58, No 6 (2016)
- Pages: 586-590
- Section: Article
- URL: https://journals.rcsi.science/1066-3622/article/view/223606
- DOI: https://doi.org/10.1134/S1066362216060047
- ID: 223606
Cite item
Abstract
The kinetics of the transformation of Np(V) into Np(IV) in 0.1 M potassium biphthalate solutions containing 5–74 mM sodium 1,2-cyclohexanediaminetetraacetate (Na2CHDTA) or in a 96–97 mM Na2CHDTA solution at 25–45°С was studied. The reaction rate at Na2CHDTA concentrations in the range 5–60 mM and pH 3.5–5.9 is described by the equation V = k[Np(V)]1.4[CHDTA], and at Na2CHDTA concentrations in the range 70–100 mM and pH 4.1–5.2, by the equation V = kA[Np(V)]1.4. Neptunium(V) forms with the CHDTA ion an activated complex in which Np(V) is reduced to Np(IV). The dimer {Np(V)}2 forming another activated complex with the CHDTA ion is formed concurrently. The latter complex decomposes along the disproportionation pathway to give Np(IV) and Np(VI). Np(VI) is reduced with the CHDTA ion to Np(V).
About the authors
V. P. Shilov
Frumkin Institute of Physical Chemistry and Electrochemistry
Author for correspondence.
Email: Shilov@ipc.rssi.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071
A. M. Fedoseev
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: Shilov@ipc.rssi.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071