Nicole Hege, Andrew T. Poore, Shane S. Galley, Benjamin J. Reinhart, Jessica A. Jackson, Shiliang Tian, Jenifer C. Shafer
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引用次数: 0
Abstract
The lanthanide (Ln) elements are critical materials that are typically extracted/mined together. Their separation by use of solvent extraction from acidic media is well known; however, there are few studies in basic media with carbonate anions. We investigated the complexation of Eu(III) and Tb(III) carbonates as solids and solutions in alkaline K2CO3, wherein we sought to access a Tb(IV) carbonate complex through ozonolysis. L3-edge XANES of Eu and Tb carbonate solids, colorless solutions, and a red-hued Tb solution (obtained by ozonolysis) all showed Ln(III) cations. The absence of evidence for a Tb(IV) complex was confirmed through XAS and EPR analyses, despite the solution exhibiting a deep red color. For solids and solutions, EXAFS results indicate molecular Ln(III)-carbonato anions. In terms of the Eu(III) carbonate coordination number, the coordination does not change upon dissolution of the solid sample. Furthermore, EXAFS for the solutions revealed evidence for the association of potassium cations with the Ln(III)-carbonato anions. This direct observation of contact ion pairing by EXAFS at room temperature is rare. The insights into Ln(III) carbonate complexation and solution speciation afforded by XANES-EXAFS, FT-IR, and EPR provides perspectives that serve as benchmarks for future computational and experimental efforts focused on caustic-side solvent extraction of Ln(III) ions.
期刊介绍:
The European Journal of Inorganic Chemistry (2019 ISI Impact Factor: 2.529) publishes Full Papers, Communications, and Minireviews from the entire spectrum of inorganic, organometallic, bioinorganic, and solid-state chemistry. It is published on behalf of Chemistry Europe, an association of 16 European chemical societies.
The following journals have been merged to form the two leading journals, European Journal of Inorganic Chemistry and European Journal of Organic Chemistry:
Chemische Berichte
Bulletin des Sociétés Chimiques Belges
Bulletin de la Société Chimique de France
Gazzetta Chimica Italiana
Recueil des Travaux Chimiques des Pays-Bas
Anales de Química
Chimika Chronika
Revista Portuguesa de Química
ACH—Models in Chemistry
Polish Journal of Chemistry
The European Journal of Inorganic Chemistry continues to keep you up-to-date with important inorganic chemistry research results.