Tellurium dichloride explained

Tellurium dichloride is a chloride of tellurium with the chemical formula TeCl₂.

Preparation

Tellurium dichloride can be produced by reacting tellurium with difluorodichloromethane.^{[1] [2]}

It can also be produced by the comproportionation of tellurium and tellurium tetrachloride.^[3]

Properties

Tellurium dichloride is a black solid that reacts with water. It will melt into a black liquid and vapourize into a purple gas.^[4] The gas consists of monomeric TeCl₂ molecules with Te–Cl bond lengths of 2.329 Å and a Cl–Te–Cl bond angle of 97.0°.

Tellurium dichloride (TeCl₂) is unstable with respect to disproportionation.^[5] Several complexes of it are known and well characterized. They are prepared by treating tellurium dioxide with hydrochloric acid in the presence of thioureas. The thiourea serves both as a ligand and as a reductant, converting Te(IV) to Te(II).

Reactions

Tellurium dichloride reacts with barium chloride in water to form barium tellurite.

References

1. Book: Gmelin, Leopold . Tellurium . Springer-Verlag . 1976 . 77834357 . en, de.
2. Aynsley . E. E. . 598. The preparation and properties of tellurium dichloride . Journal of the Chemical Society (Resumed) . Royal Society of Chemistry (RSC) . 1953 . 0368-1769 . 10.1039/jr9530003016 . 3016.
3. Book: Haaland, Arne . Molecules and models : the molecular structures of main group element compounds . Oxford University Press . Oxford New York . 2008 . 978-0-19-152860-6 . 226969121.
4. Fernholt . Liv . Haaland . Arne . Volden . Hans V. . Kniep . Rüdiger . The molecular structure of tellurium dichloride, TeCl₂, determined by gas electron diffraction . Journal of Molecular Structure . Elsevier BV . 128 . 1–3 . 1985 . 0022-2860 . 10.1016/0022-2860(85)85037-7 . 29–31. free . 1985JMoSt.128...29F .
5. Liv . Fernholt . Arne . Haaland . Arne Haaland . Hans V. . Volden . Rüdiger . Kniep . The molecular structure of tellurium dichloride, TeCl₂, determined by gas electron diffraction . Journal of Molecular Structure . 1985 . 128 . 1–3 . 29–31 . 10.1016/0022-2860(85)85037-7. free . 1985JMoSt.128...29F .