Europium(II) hydroxide

Europium(II) hydroxide is an inorganic compound, with the chemical formula of Eu(OH)2. It can exist as the dihydrate Eu(OH)2·H2O.

Preparation
The monohydrate of europium(II) hydroxide can be obtained by the reaction of metal europium and 10 mol/L sodium hydroxide solution. There are some sources that use europium(III) chloride as a raw material, and prepare it by reacting the Jones reductor with sodium hydroxide solution.

Properties
Europium(II) hydroxide belongs to the orthorhombic crystal system, a=6.701 ± 0.002, b=6.197 ± 0.002, c=3.652 ± 0.001 A. It thermally decomposes to form europium(II) oxide (EuO); it is readily oxidized to europium(III) hydroxide in air.