[Research Article] Characterization of berkelium(III) dipicolinate and borate compounds in solution and the solid state
Berkelium is positioned at a crucial location in the actinide series between the inherently stable half-filled 5f7 configuration of curium and the abrupt transition in chemical behavior created by the onset of a metastable divalent state that starts at californium. However, the mere 320-day half-life of berkelium’s only available isotope, 249Bk, has hindered in-depth studies of the element’s coordination chemistry. Herein, we report the synthesis and detailed solid-state and solution-phase characterization of a berkelium coordination complex, Bk(III)tris(dipicolinate), as well as a chemically distinct Bk(III) borate material for comparison. We demonstrate that berkelium’s complexation is analogous to that of californium. However, from a range of spectroscopic techniques and quantum mechanical calculations, it is clear that spin-orbit coupling contributes significantly to berkelium’s multiconfigurational ground state. Authors: Mark A. Silver, Samantha K. Cary, Jason A. Johnson, Ryan E. Baumbach, Alexandra A. Arico, Morgan Luckey, Matthew Urban, Jamie C. Wang, Matthew J. Polinski, Alexander Chemey,...