The hydrolysis of hydroxamic acid complexants in the presence of non-oxidizing metal ions 2: Neptunium (IV) ions.

Andrieux, Fabrice Pierre Louis and Boxall, C. and May, I. and Taylor, R. J. (2008) The hydrolysis of hydroxamic acid complexants in the presence of non-oxidizing metal ions 2: Neptunium (IV) ions. Journal of Solution Chemistry, 37 (2). pp. 215-232. ISSN 0095-9782

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Abstract

Hydroxamic acids are salt free, organic compounds with affinities for cations such as Fe3+, Np4+ and Pu4+, and have been identified as suitable reagents for the control of Pu and Np in advanced nuclear fuel reprocessing. The results of a UV-visible, near-IR spectrophotometric study of the 1:1 and 2:1 complexes formed between formo- and aceto-hydroxamic acids (FHA, AHA) and Np(IV) ions are interpreted using speciation diagrams for the identification of the species present at different pH and ligand to metal ratios. A kinetic model that describes the instability of the complex due to hydrolysis of the hydroxamate moiety, previously developed for the Fe(III)-AHA complexes (Andrieux et al. in J. Solution Chem. 36:1201-1217, [2007]), is tested here against experimental Np(IV)-FHA data. Consequently, the complexation constant for formation of the 1:1 Np(IV)-FHA complex in nitric acid is estimated at K-1=2715 and indications are that complexation protects the ligand against hydrolysis at 0.1 > pH >-0.1.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Solution Chemistry
Additional Information:
The original publication is available at www.springerlink.com
Uncontrolled Keywords:
/dk/atira/pure/researchoutput/libraryofcongress/ta
Subjects:
ID Code:
26522
Deposited By:
Deposited On:
27 May 2009 09:26
Refereed?:
Yes
Published?:
Published
Last Modified:
11 Aug 2020 00:10