PuIII

PuIII, commonly written Pu3+, denotes plutonium in the trivalent oxidation state. It is one of several oxidation states plutonium can adopt in aqueous solution, including Pu2+, Pu4+, Pu5+, and Pu6+. In many environments Pu3+ is relatively unstable compared with Pu4+ because Pu(III) is readily oxidized to Pu(IV) by oxidants such as dissolved oxygen or permanganate.

Electronic configuration and properties: The Pu3+ ion is typically described as having the electron configuration [Rn]5f5. The 5f5 configuration influences its ionic radius, color in solution, and tendency to form bonds with ligands, as well as its magnetic properties.

Solutions and speciation: Pu3+ forms coordination compounds with ligands like chloride, fluoride, carbonate, oxalate, and chelating agents (for example EDTA). The stability of Pu3+ complexes depends on pH and redox conditions. In aqueous solutions, Pu3+ tends to hydrolyze with increasing pH, forming colloidal or solid hydroxide species (Pu(OH)3), which can precipitate.

Redox behavior: Pu3+ is a reducing agent relative to Pu4+ and can be oxidized by oxidants present in the environment or during processing. Conversely, strong reducing conditions can help stabilize Pu3+ against oxidation.

Applications and safety: Pu3+ chemistry is studied mainly in actinide coordination chemistry and radiochemical separations. All plutonium compounds are radioactive and toxic; handling requires appropriate radiological controls, containment, and licensed facilities.

Isotopes and context: Plutonium isotopes vary, with Pu-239 and Pu-241 common in nuclear applications. Any Pu3+ sample contains radioactive material and must be tracked and disposed of according to safety regulations.