Thulium(II) iodide

Thulium(II) iodide is an inorganic compound with the chemical formula TmI2.

Preparation and properties
Thulium(II) iodide can be obtained by reacting thulium(III) iodide and alkali metals in a tantalum container at 700~800°C. TmI2 can be obtained by using lithium and sodium as reducing agents, while potassium, rubidium and caesium can generate the perovskite structure MTmI3. TmI2 can also react directly with CsI (340 °C) to generate CsTmI3.

Thulium(II) iodide can also be prepared by reacting thulium and mercury(I) iodide. The reaction process is as follows:


 * 2 Tm + 3 HgI2 → 2 TmI3 + 3 Hg
 * Tm + HgI2 → TmI2 + Hg
 * Tm + 2 TmI3 → 3 TmI2