Chemistry:Plutonium trioxide

Plutonium trioxide

Names
Other names Plutonium(VI) oxide
Identifiers
CAS Number	12311-78-3 N
3D model (JSmol)	Interactive image
InChI InChI=1S/H2O.3O.Pu/h1H2;;;;/q;3*-2;+6 Key: XKRCXWINTGBBQF-UHFFFAOYSA-N
SMILES [Pu+6].[O-2].[O-2].[O-2].O
Properties
Chemical formula	PuO 3
Molar mass	536 g·mol−1
Appearance	golden-red crystals (hydrates)
Solubility in water	insoluble (hydrates)
Related compounds
Other anions	Uranium trioxide Neptunium trioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Tracking categories (test):

• SizeSet

Plutonium trioxide is an inorganic compound of plutonium and oxygen with the chemical formula PuO
3. This is a high-order oxide of plutonium where the metal is in the +6 oxidation state. The compound is less stable and less common than the common plutonium dioxide PuO
2.

Theoretical calculations on molecular actinide trioxides predict that while molecular plutonium trioxide should attain the +6 oxidation state for plutonium, the molecular trioxides of the heavier actinides should be regarded as having the actinide in the +5 oxidation state

Synthesis

Initialy, plutonium(III) hydroxide is obtained, which then transforms into plutonium(IV) hydroxide in air, and then oxygen containing ozone is passed through the suspension:

Pu(OH)
4 + O
3 → PuO
3 · H₂O + O
2 + H
2O

Physical properties

Plutonium trioxide forms hydrates of variable composition PuO
3•xH
2O, where x = 0.8–1, which are golden-red crystals. Not isolated in the anhydrous state: it decomposes when attempted to separate the water. When stored in the air, the compound absorbs moisture up to the composition of PuO
3•H
2O. Insoluble in water.

Chemical properties

Decomposes when heated:

2PuO
3 · xH
2O → 2PuO
2 + O
2 + 2xH
2O

Dissolves in acids, forming salts:

PuO
3 · xH
2O + 2HNO
3 → PuO
2(NO
3)
2 + (x + 1) · H₂O