How Amidoximate Binds the Uranyl Cation

This study identifies how the amidoximate anion, AO,
interacts
with the uranyl cation, UO22+. Density functional
theory calculations have been used to evaluate possible binding motifs
in a series of [UO2(AO)x(OH2)y]2–x (x = 1–3) complexes. These motifs
include monodentate binding to either the oxygen or the nitrogen atom
of the oxime group, bidentate chelation involving the oxime oxygen
atom and the amide nitrogen atom, and η2 binding
with the N–O bond. The theoretical results establish the η2 motif to be the most stable form. This prediction is confirmed
by single-crystal X-ray diffraction of UO22+ complexes with acetamidoxime and benzamidoxime anions.