A Mixed-Valent Uranium Phosphonate Framework Containing U super(IV), U super(V), and U super(VI)

It is shown that U super(V)O sub(2) super( +) ions can reside at U super(VI)O sub(2) super(2+) lattice sites during mild reduction and crystallization process under solvothermal conditions, yielding a complicated and rare mixed-valent uranium phosphonate compound that simultaneously contains U super(IV), U super(V), and U super(VI). The presence of uranium with three oxidation states was confirmed by various characterization techniques, including X-ray crystallography, X-ray photoelectron, electron paramagnetic resonance, FTIR, UV/Vis-NIR absorption, and synchrotron radiation X-ray absorption spectroscopy, and magnetism measurements. Three's company: A complex uranium compound was synthesized by a redox-active solvothermal reaction. It is the first phosphonate compound that contains three oxidation states of uranium simultaneously.