Tritellurium dichloride

Tritellurium dichloride is the inorganic compound with the formula Te3Cl2. It is one of the more stable lower chlorides of tellurium.

Tritellurium dichloride
Identifiers
  • 12526-08-8 N
3D model (JSmol)
  • InChI=1S/Cl2Te3/c1-5(2)4-3
    Key: TWWCHESXRMILGP-UHFFFAOYSA-N
  • [Te][Te][Te](Cl)Cl
Properties
Te3Cl2
Molar mass 453.71 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N (what is YN ?)
Infobox references
Structure of trans-[TeCl2(SC(NMe2)2)2] (H atoms omitted).[1]

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-.[2] It is a semiconductor with a band gap of 1.52 eV, which is larger than that for elemental Te (0.34 eV).[3] It is prepared by heating Te with the appropriate stoichiometry of chlorine.[4]

Other lower tellurium chlorides

Te2Cl2 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.[3]

Tellurium dichloride (TeCl2) is unstable with respect to disproportionation, 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.[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).

References
  1. O. Foss, K. Maartmann-Moe (1986). "Crystal and Molecular Structures of trans Square-Planar Complexes of Tellurium Dichloride, Dibromide and Diiodide with Tetramethylthiourea, TeL2X2. Bond Lengths in Centrosymmetric Tellurium(II) Complexes". Acta Chemica Scandinavica A. 40: 675. doi:10.3891/acta.chem.scand.40a-0675.CS1 maint: uses authors parameter (link)
  2. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  3. Zhengtao Xu "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions and Polycations" in Handbook of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium and Tellurium, Francesco Devillanova, Editor, 2006, RSC. pp. 381-416. Royal Society doi:10.1039/9781847557575-00455
  4. R. Kniep, D. Mootz, A. Rabenau "Zur Kenntnis der Subhalogenide des Tellurs" Zeitschrift für anorganische und allgemeine Chemie 1976, Volume 422, pages 17–38. doi:10.1002/zaac.19764220103
  5. Liv Fernholt, Arne Haaland , Hans V. Volden, Rüdiger Kniep "The molecular structure of tellurium dichloride, TeCl2, determined by gas electron diffraction" Journal of Molecular Structure 1985, volume 128, pages 29-31.doi:10.1016/0022-2860(85)85037-7


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