Triiodide

In chemistry, triiodide usually refers to the triiodide ion, I₃−. This anion, one of the polyhalogen ions, is composed of three iodine atoms. It is formed by combining aqueous solutions of iodide salts and iodine. Some salts of the anion have been isolated, including thallium(I) triiodide (Tl+-) and ammonium triiodide (+-).