Tritellurium dichloride is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

with the formula Te₃ Cl₂. It is one of the more stable lower chlorides of tellurium.

Preparation and properties

Te₃Cl₂ is a gray solid. Its structure consists of a long chain of Te atoms, with every third Te center carrying two chloride ligands for the repeat unit -Te-Te-TeCl₂-. It is a semiconductor with a band gap of 1.52 eV, which is larger than that for elemental Te (0.34 eV). It is prepared by heating Te with the appropriate stoichiometry of chlorine.

Other lower tellurium chlorides

Te₂Cl₂ (ditellurium dichloride) is a yellow liquid prepared by reaction of lithium polytellurides with TeCl₄. Te₂Cl, also a polymer, is a metastable gray solid, tending to convert to Te₃Cl₂ and TeCl₄. Tellurium dichloride (TeCl₂) is unstable with respect to

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can b ...

, and has not been isolated as a solid, but has been characterised as the main component of the vapor formed with TeCl₄ and hot Te. Several complexes of it are known and well characterized. They are prepared by treating tellurium dioxide with

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbol ...

in the presence of

thiourea Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), except that the oxygen atom is replaced by a sulfur atom (as implied by the ''thio-'' prefix); however, the properties of urea ...

s. The thiourea serves both as a ligand and as a reductant, converting Te(IV) to Te(II).

References

{{Chlorides Chlorides Nonmetal halides Tellurium halides Inorganic polymers Conductive polymers