Lawrence Berkeley National Laboratory
Chelation and stabilization of berkelium in oxidation state +IV.
- Author(s): Deblonde, Gauthier J-P
- Sturzbecher-Hoehne, Manuel
- Rupert, Peter B
- An, Dahlia D
- Illy, Marie-Claire
- Ralston, Corie Y
- Brabec, Jiri
- de Jong, Wibe A
- Strong, Roland K
- Abergel, Rebecca J
- et al.
Published Web Locationhttps://doi.org/10.1038/nchem.2759
Berkelium (Bk) has been predicted to be the only transplutonium element able to exhibit both +III and +IV oxidation states in solution, but evidence of a stable oxidized Bk chelate has so far remained elusive. Here we describe the stabilization of the heaviest 4+ ion of the periodic table, under mild aqueous conditions, using a siderophore derivative. The resulting Bk(IV) complex exhibits luminescence via sensitization through an intramolecular antenna effect. This neutral Bk(IV) coordination compound is not sequestered by the protein siderocalin-a mammalian metal transporter-in contrast to the negatively charged species obtained with neighbouring trivalent actinides americium, curium and californium (Cf). The corresponding Cf(III)-ligand-protein ternary adduct was characterized by X-ray diffraction analysis. Combined with theoretical predictions, these data add significant insight to the field of transplutonium chemistry, and may lead to innovative Bk separation and purification processes.