Plutonium tetroxide
Plutonium tetraoxide is an inorganic binary compound of plutonium and oxygen with the chemical formula. This is an exotic, higher-order oxide of plutonium where the metal is in the rare +8 oxidation state. The compound is volative and very hard to isolate.
Synthesis
Plutonium tetraoxide may be made by the addition of excess hydrogen peroxide to acidified solutions of plutonium salt:Physical properties
Plutonium tetraoxide forms as a crystalline precipitate of light green color, the shades of which vary depending on the impurities of the anions that are captured during precipitation. The precipitate contains impurities of other plutonium oxides, and its actual composition roughly corresponds to the formula.It is insoluble in water, and forms crystallohydrates of variable composition. Theoretical calculations show that the molecule has the structure +-, i.e. plutonium is hexavalent and has an oxidation state of +5.