Tellurium iodide is an inorganic compound with the formula TeI. Two forms are known. Their structures differ from the other monohalides of tellurium. There are three subiodides of tellurium, ñ-TeI, ò-TeI, and Te<sub>2</sub>I, and one tellurium tetraiodide.
TeI is a gray solid formed by the solvothermal reaction of tellurium metal and iodine in hydroiodic or chloroaluminic acid. When this reaction is conducted near 270 ðC gives the ñ-TeI, which is triclinic. When the same mixture is heated to 150 ðC, one obtains the metastable monoclinic phase ò-TeI. The compounds are related structurally to Te<sub>2</sub>I (see ditellurium bromide), but the additional iodide groups do not bridge to other Te centers.
The corresponding monochloride and monobromide are molecular compounds with the formula Te<sub>2</sub>X<sub>2</sub>.
Although TeI<sub>2</sub> has not been isolated in bulk, complexes of the type TeI<sub>2</sub>(thiourea)<sub>2</sub> are well characterized. These complexes precipitate upon treatment of aqueous solutions of the related tellurium dibromide complex with sodium iodide.