The plutonyl ion is an oxycation of plutonium in the oxidation state +6, with the chemical formula PuO2+2.
The plutonyl ion forms many complexes, particularly with ligands that have oxygen donor atoms.
Distinct optical absorbance bands at 842 and 845 nm were observed for the mononuclear and dinuclear hydrolysis species.
The most common arrangement is for the so-called equatorial ligands to lie in a plane perpendicular to the O–Pu–O line and passing through the plutonium atom.
Replacing the water molecules that are bound to the plutonyl ion in aqueous solution by a second, hydrophobic, ligand increases the solubility of the neutral complex in the organic solvent.
[8] The solubility of plutonyl nitrate in organic solvents is utilized in the PUREX process.
[9] Plutonyl complex chemistry is an active research area, for dealing with environmental contamination.