Peroxouranyl-Containing W48 Wheel: Synthesis, Structure, and Detailed Infrared and Raman Spectroscopy Study

We report on the first example of a peroxouranium-containing {P8W48} wheel, [{(UO2)(4)(O-2)(4)}(2)(P8W48O184)](40-) (1), which was synthesized by a one-pot reaction of UO2(NO3)(2)center dot 6H(2)O with the 48-tungsto-8-phosphate wheel [H7P8W48O184](33-) and aqueous hydrogen peroxide in a pH 6 lithium acetate solution at 50 degrees C. Polyanion 1 comprises two tetrauranyl squares with side-on peroxo bridging ligands in the cavity of the {P8W48} wheel, and was isolated as the hydrated potassium-lithium salt K18Li22[{(UO2)(4)(O-2)(4)}(2)(P8W48O184)]center dot 133H(2)O (KLi-1), which was characterized in the solid state by single-crystal X-ray diffraction, as well as thermogravimetric and elemental analyses. A detailed Fourier transform infrared and Raman spectroscopy study was also performed.