1 research outputs found
Electronic Structures and Unusual Chemical Bonding in Actinyl Peroxide Dimers [An<sub>2</sub>O<sub>6</sub>]<sup>2+</sup> and [(An<sub>2</sub>O<sub>6</sub>)(12-crown‑4 ether)<sub>2</sub>]<sup>2+</sup> (An = U, Np, and Pu)
As
known, actinyl peroxides play important roles in environmental
transport of actinides, and they have strategic importance in the
application of nuclear industry. Compared to the most studied uranyl
peroxides, the studies of transuranic counterparts are still few,
and more information about these species is needed. In this work,
experimentally inspired actinyl peroxide dimers ([An2O6]2+, An = U, Np, and Pu) have been studied and
analyzed by using density functional theory and multireference wave
function methods. This study determines that the three [An2O6]2+ have unique electronic structures and
oxidation states, as [(UVIO2)2(O2)2–]2+, [(NpVIIO2)2(O2–)2]2+, and mixed-valent [(PuVI/VO2)2(O2)1–]2+. This study demonstrates
the significance of two bridging oxo ligands with at most four electron
holes availability in ionically directing actinyl and resulting in
the unusual multiradical bonding in [(PuVI/VO2)2(O2)1–]2+. In
addition, thermodynamically stable 12-crown-4 ether (12C4) chelated
[(An2O6)(12C4)2]2+ complexes
have been predicted, that could maintain these unique electronic structures
of [An2O6]2+, where the An ←
O12C4 dative bonding shows a trend in binding capacity
of 12C4 from κ4 (U) to κ3 (Np) and
κ4 (Pu). This study reveals the interesting electronic
character and bonding feature of a series of early actinide elements
in peroxide complexes, which can provide insights into the intrinsic
stability of An-containing species