[3] Dysprosium(II) iodide is a dark purple-black solid that is easily deliquescent and can only be stored in a dry inert gas or a vacuum.

In the air, it will absorb moisture and become a hydrate, but they are unstable and will quickly convert into iodide oxides and release hydrogen gas.

This process occurs faster in the presence of water.

[1] It can form complexes with tetrahydrofuran, butanol and phenol.

[3] The reaction between dysprosium(II) iodide and silicon tetrachloride produces trichlorosilyl radicals, which can catalyze the trimerization of alkynes.