Plutonium(IV) nitrate

Plutonium (IV) nitrate is an inorganic compound, a salt of plutonium and nitric acid with the chemical formula Pu(NO₃)₄. The compound dissolves in water and forms crystalline hydrates as dark green crystals.^[1][2]

Plutonium(IV) nitrate

Names
Other names Plutonium tetranitrate
Identifiers
CAS Number	13823-27-3 Y 53745-09-8 (238Pu) Y (239Pu): 13968-56-4 Y 55252-44-3 (hydrates) Y (trihydrate): 159472-02-3 Y (pentahydrate): 61204-24-8 Y
3D model (JSmol)	Interactive image (trihydrate): Interactive image (pentahydrate): Interactive image
ChemSpider	14691097
InChI InChI=1S/4NO3.Pu/c4*2-1(3)4;/q4*-1;+4 Key: XOQIPTFXWRJKPQ-UHFFFAOYSA-N (trihydrate): InChI=1S/4NO3.5H2O.Pu/c4*2-1(3)4;;;;;;/h;;;;5*1H2;/q4*-1;;;;;;+4 Key: OHJOWNGCXJSPGF-UHFFFAOYSA-N
SMILES [N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[Pu+4] (trihydrate): [N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].O.O.O.[Pu+4] (pentahydrate): [N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].O.O.O.O.O.[Pu+4]
Properties
Molar mass	492.02
Appearance	Dark green crystals (hydrates)
Solubility in water	Soluble
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Extremely toxic(T+) and radioactive; carcinogen
GHS labelling:
Pictograms
Signal word	Warning
NFPA 704 (fire diamond)	4 2 0
Related compounds
Related compounds	Neptunium(IV) nitrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

Crystals of dark green to black-green composition Pu(NO₃)₄•5H₂O precipitate with a slow (months) evaporation of a solution of a plutonium (IV) compound in nitric acid.^[3][4]

Physical properties

Plutonium (IV) nitrate forms a crystalline hydrate of the composition Pu(NO₃)₄•5H₂O—dark green crystals of rhombic crystal structure, space group F dd2, cell parameters: a = 1.114 nm, b = 2.258 nm, c = 1.051 nm, Z = 8.

Crystalline hydrate melts in its own crystallization water at 95–100 °C.

It dissolves well in nitric acid (dark green solution) and water (brown solution). Also dissolves in acetone and ether.

Chemical properties

When heated to 150–180 °C, it decomposes with autooxidation to plutonium (VI) with the formation of plutonyl nitrate (PuO₂(NO₃)₂). Upon evaporation of concentrated nitric acid solutions of plutonium nitrate and alkali metal nitrates, double nitrates of the composition M₂[Pu(NO₃)₆] are formed, where M = Cs⁺, Rb⁺, K⁺, Tl⁺, NH₄⁺, analogous to ceric ammonium nitrate.

Toxicity

Plutonium nitrate is both radioactive and extremely toxic due to its high solubility in water.