Plutonium (IV) nitrate is an inorganic compound, a salt of plutonium and nitric acid with the chemical formula Pu(NO<sub>3</sub>)<sub>4</sub>. The compound dissolves in water and forms crystalline hydrates as dark green crystals.
Crystals of dark green to black-green composition Pu(NO<sub>3</sub>)<sub>4</sub>â¢5H<sub>2</sub>O precipitate with a slow (months) evaporation of a solution of a plutonium (IV) compound in nitric acid.
Plutonium (IV) nitrate forms a crystalline hydrate of the composition Pu(NO<sub>3</sub>)<sub>4</sub>â¢5H<sub>2</sub>OâÂÂdark 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 95âÂÂ100 ðC.
It dissolves well in nitric acid (dark green solution) and water (brown solution). Also dissolves in acetone and ether.
When heated to 150âÂÂ180 ðC, it decomposes with autooxidation to plutonium (VI) with the formation of plutonyl nitrate (PuO<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>). Upon evaporation of concentrated nitric acid solutions of plutonium nitrate and alkali metal nitrates, double nitrates of the composition M<sub>2</sub>[Pu(NO<sub>3</sub>)<sub>6</sub>] are formed, where M = Cs<sup>+</sup>, Rb<sup>+</sup>, K<sup>+</sup>, Tl<sup>+</sup>, NH<sub>4</sub><sup>+</sup>, analogous to ceric ammonium nitrate.
Plutonium nitrate is both radioactive and extremely toxic due to its high solubility in water.