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Polyoxometalates as ligands to synthesize, isolate and characterize compounds of rare isotopes on the microgram scale

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The synthesis and study of radioactive compounds are both inherently limited by their toxicity, cost and isotope scarcity. Traditional methods using small inorganic or organic complexes typically require milligrams of sample—per attempt—which for some isotopes is equivalent to the world’s annual supply. Here we demonstrate that polyoxometalates (POMs) enable the facile formation, crystallization, handling and detailed characterization of metal–ligand complexes from microgram quantities owing to their high molecular weight and controllable solubility properties. Three curium–POM complexes were prepared, using just 1–10 μg per synthesis of the rare isotope 248Cm3+, and characterized by single-crystal X-ray diffraction, showing an eight-coordinated Cm3+ centre. Moreover, spectrophotometric, fluorescence, NMR and Raman analyses of several f-block element–POM complexes, including 243Am3+ and 248Cm3+, showed otherwise unnoticeable differences between their solution versus solid-state chemistry, and actinide versus lanthanide behaviour. This POM-driven strategy represents a viable path to isolate even rarer complexes, notably with actinium or transcalifornium elements.

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Fig. 1: Leveraging POMs to obtain detailed structural information on actinide complexes from microgram quantities.
Fig. 2: Luminescence properties of the W5 POM complexes with trivalent lanthanide and curium ions.
Fig. 3: Absorbance properties of americium and curium ions upon complexation with POMs.
Fig. 4: Steady-state and time-correlated fluorescence properties of lanthanide–POM and curium–POM complexes.
Fig. 5: Luminescence lifetimes of Cm3+ complexes in solution and Cm–POM transition from solution to the solid state.
Fig. 6: SCXRD structures of transplutonium element complexes with POMs.

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Data availability

All data that support the conclusions in this study are present in the manuscript and/or the Supplementary Information. Crystallographic data for the structures reported in this Article have been deposited at the Cambridge Crystallographic Data Centre under the following CCDC accession codes: 2105534 (CmPW11-α), 2105535 (CmPW11-β), 2105623 (NdPW11), 2105638 (EuPW11), 2114774 (CmBW11), 2114775 (EuBW11), 2127430 (NdBW11), 2127431 (SmBW11), 2127432 (SmPW11), 2127433 (EuW5) and 2127434 (NdW5). Copies of the data can be obtained free of charge via Source data are provided with this paper.


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This work was performed under the auspices of the US Department of Energy (DOE) by the Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and was supported by the LDRD Program under the LLNL project 20-LW-017. Release number: LLNL-JRNL-829648. I.C. and M.N. acknowledge the US DOE, National Nuclear Security Administration (NNSA) for work conducted at Oregon State University, award number DE-NA0003763. I.C. acknowledges the US DOE’s SCGSR fellowship.

Author information

Authors and Affiliations



G.J.-P.D. supervised the project. I.C. and G.J.-P.D. conducted the synthetic and spectroscopic experiments. I.C., J.R.I.L., M.N. and G.J.-P.D. conducted the crystallography experiments and analysed the crystallographic data. C.A.C., H.E.M. and A.M.S. conducted the NMR experiments. G.J.-P.D. wrote the original draft of the manuscript. G.J.-P.D., M.N. and M.Z. acquired funding. All authors made intellectual contributions to the project, and also reviewed and edited the manuscript.

Corresponding author

Correspondence to Gauthier J.-P. Deblonde.

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Nature Chemistry thanks Kristina Kvashnina, Annette Rompel and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–26 and Tables 1–13.

Supplementary Data 1

SCXRD structure of CsCmBW11.

Supplementary Data 2

SCXRD structure of CsCmPW11-α.

Supplementary Data 3

SCXRD structure of CsCmPW11-β.

Supplementary Data 4

SCXRD structure of CsEuBW11.

Supplementary Data 5

SCXRD structure of EuPW11.

Supplementary Data 6

SCXRD structure of EuW5.

Supplementary Data 7

SCXRD structure of NdBW11.

Supplementary Data 8

SCXRD structure of NdPW11.

Supplementary Data 9

SCXRD structure of NdW5.

Supplementary Data 10

SCXRD structure of SmBW11.

Supplementary Data 11

SCXRD structure of SmPW11.

Supplementary Data 12

Data points shown in Supplementary Fig. 22b.

Source data

Source Data Fig. 1

Data points shown in Fig. 1a.

Source Data Fig. 2

Fluorescence emission and excitation data shown in Figs. 2a,c,d.

Source Data Fig. 3

UV-visible absorbance data shown in Fig. 3a–f.

Source Data Fig. 4

Fluorescence emission, excitation amd decay data shown in Fig. 4a–f.

Source Data Fig. 5

Fluorescence and Raman data shown in Fig. 4b–d.

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Colliard, I., Lee, J.R.I., Colla, C.A. et al. Polyoxometalates as ligands to synthesize, isolate and characterize compounds of rare isotopes on the microgram scale. Nat. Chem. 14, 1357–1366 (2022).

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