Tritellurium dichloride

(Redirected from Tellurium(II) chloride)

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

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

Preparation and properties edit

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 edit

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.[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 edit

  1. ^ Foss, O.; Maartmann-Moe, K. (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.
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  3. ^ a b Xu, Zhengtao (2006). "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions and Polycations". In Devillanova, Francesco (ed.). Handbook of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium and Tellurium. Royal Society of Chemistry. pp. 381–416. doi:10.1039/9781847557575-00455.
  4. ^ Kniep, R.; Mootz, D.; Rabenau, A. (1976). "Zur Kenntnis der Subhalogenide des Tellurs". Zeitschrift für anorganische und allgemeine Chemie. 422: 17–38. doi:10.1002/zaac.19764220103.
  5. ^ Fernholt, Liv; Haaland, Arne; Volden, Hans V.; Kniep, Rüdiger (1985). "The molecular structure of tellurium dichloride, TeCl2, determined by gas electron diffraction". Journal of Molecular Structure. 128 (1–3): 29–31. Bibcode:1985JMoSt.128...29F. doi:10.1016/0022-2860(85)85037-7.