Iodine trichloride is an interhalogen compound of iodine and chlorine. It is bright yellow and in the solid state is present as a planar dimer I2Cl6, Cl2I(μ-Cl)2ICl2, with two bridging Cl atoms.
It can be prepared by reacting iodine with an excess of liquid chlorine at −70 °C. In the melt it is conductive, which may indicate dissociation:
- I2Cl6 ICl2+ + ICl4−
Iodine trichloride can be created by heating a mixture of liquid iodine and chlorine gas to 105 °C.
It is an oxidizing agent, capable of causing fire on contact with organic materials.