Advancing understanding of actinide(iii) (Ac, Am, Cm) aqueous complexation chemistry

Abstract

Actinide complexation from aqueous acetic acid/acetate buffered solutions is described. The number of water ligands was directly correlated with the acetate concentration and characterized by X-ray absorption and optical spectroscopy.

Chelating the Alpha Therapy Radionuclides 225Ac3+ and 213Bi3+ with 18-Membered Macrocyclic Ligands Macrodipa and Py-Macrodipa

“…Because the ionic radii and coordination chemistry of Ac 3+ and La 3+ are similar, we optimized Ac 3+ –macrodipa and Ac 3+ –py-macrodipa starting from the geometries of the corresponding La 3+ complexes, which attain the symmetric Conformation A. , Within these structures (Figure ), the Ac–O interatomic distances are 2.45–2.48 Å for negatively charged O and 2.70–2.79 Å for neutral O, whereas the Ac–N interactions range from 2.76–2.92 Å. These calculated distances are close to experimentally measured Ac–O and Ac–N interatomic distances. − Additionally, we optimized both complexes in Conformation B. Consistent with our expectations, Conformation B is energetically unfavored for both complexes (Table S2).…”

In situ beam reduction of Pu(IV) and Bk(IV) as a route to trivalent transuranic coordination complexes with hydroxypyridinone chelators

“…Over the past decade there has been a surge in interest in the coordination chemistry of trivalent and tetravalent transuranic elements due to the distinctive chemical properties of the actinides, increased availability of materials, and improvements in instrumentation development and data processing (Carter, Pallares et al, 2020), particularly for X-ray absorption spectroscopy (XAS) and diffraction techniques (Galbis et al, 2010;Cary et al, 2015;Ferrier et al, 2017;Kelley et al, 2018;Mu ¨ller et al, 2021;Jones et al, 2021). Recent highlights of these efforts include the first crystal structure of Bk(III) (Silver et al, 2016), stabilization of Bk(IV) in aqueous solution (Deblonde et al, 2017), measurement of the first bond distance with Es(III) (Carter, Shield et al, 2021), and a significant improvement in our understanding of how covalency and heterogeneity affect 5f-orbital bonding (Allred et al, 2015;Cross et al, 2017;Kelley et al, 2017;Su et al, 2018;Stein et al, 2019;Wilson et al, 2020;Bessen et al, 2021).…”