Thorium diiodide is an iodide of thorium, with the chemical formula of ThI<sub>2</sub>. It is an electride with the ionic formula Th<sup>4+</sup>(I<sup>âÂÂ</sup>)<sub>2</sub>e<sup>âÂÂ</sup><sub>2</sub>. It is air-sensitive.
Thorium diiodide cn be prepared by heating thorium tetraiodide in stoichiometric amounts of thorium:
It can also be prepared by directly reacting thorium and iodine:
Thorium diiodide can also be prepared from the decomposition of thorium triiodide at temperatures above 550 ðC:
Like the diiodides of cerium, praseodymium and gadolinium, it has a metallic gold lustre and high electrical conductivity.