EXAFS Determinations of Uranium Structures: The Uranyl Ion Complexed with Tartaric, Citric, and Malic Acids
1996; American Chemical Society; Volume: 35; Issue: 3 Linguagem: Inglês
10.1021/ic9508536
ISSN1520-510X
AutoresP. G. Allen, David K. Shuh, J. J. Bucher, Ν. Μ. Edelstein, Τ. Reich, Melissa A. Denecke, H. Nitsche,
Tópico(s)Radioactive contamination and transfer
ResumoU LIII-edge EXAFS spectra were measured for 1:1 mixtures of the uranyl ion with tartaric, malic, and citric acids. The room-temperature EXAFS spectra of these mixtures demonstrate the characteristic uranium−oxygen interactions of the uranyl ion UO22+ and also show a U−U interaction at 3.92 Å, indicating the presence of a uranyl dimer. On the basis of models proposed by Martell et al. from earlier potentiometric titration experiments, it is concluded that the dimer is the ligand-bridged species (UO2)2(L)2, in which bridging occurs through the α-hydroxyl groups of the polycarboxylate ligands.
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