Thorium diiodide

Thorium diiodide is an iodide of thorium, with the chemical formula of ThI2. It is an electride with the ionic formula Th4+(I-)2e-2. It is air-sensitive.

Preparation
Thorium diiodide cn be prepared by heating thorium tetraiodide in stoichiometric amounts of thorium:


 * ThI4 + Th -> 2 ThI2

It can also be prepared by directly reacting thorium and iodine:


 * Th + I2 -> ThI2

Thorium diiodide can also be prepared from the decomposition of thorium triiodide at temperatures above 550 °C:


 * 2 ThI3 -> ThI4 + ThI2

Properties
Like the diiodides of cerium, praseodymium and gadolinium, it has a metallic gold lustre and high electrical conductivity.