Spectroscopic and Computational Characterization of Diethylenetriaminepentaacetic Acid/Transplutonium Chelates: Evidencing Heterogeneity in the Heavy Actinide(III) Series |
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| Authors: | Dr Gauthier J‐P Deblonde Dr Morgan P Kelley Dr Jing Su Dr Enrique R Batista Dr Ping Yang Dr Corwin H Booth Prof Rebecca J Abergel |
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| Institution: | 1. Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA;2. Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, USA;3. Department of Nuclear Engineering, University of California, Berkeley, Berkeley, CA, USA |
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| Abstract: | The chemistry of trivalent transplutonium ions (Am3+, Cm3+, Bk3+, Cf3+, Es3+…) is usually perceived as monotonic and paralleling that of the trivalent lanthanide series. Herein, we present the first extended X‐ray absorption fine structure (EXAFS) study performed on a series of aqueous heavy actinide chelates, extending past Cm. The results obtained on diethylenetriaminepentaacetic acid (DTPA) complexes of trivalent Am, Cm, Bk, and Cf show a break to much shorter metal–oxygen nearest‐neighbor bond lengths in the case of Cf3+. Corroborating those results, density functional theory calculations, extended to Es3+, suggest that the shorter Cf?O and Es?O bonds could arise from the departure of the coordinated water molecule and contraction of the ligand around the metal relative to the other MIIIDTPA(H2O)]2? (M=Am, Cm, Bk) complexes. Taken together, these experimental and theoretical results demonstrate inhomogeneity within the trivalent transplutonium series that has been insinuated and debated in recent years, and that may also be leveraged for future nuclear waste reprocessing technologies. |
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| Keywords: | actinides berkelium californium chelates EXAFS spectroscopy |
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