tellurium dichloride
{{Chembox
| ImageFile1 = Tellurdichlorid.svg
| ImageFile2 = Tellurium-dichloride-gas-phase-3D-bs-17.png
|Section1={{Chembox Identifiers
| CASNo=10025-71-5
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID = 2588376
| PubChem = 3341691
| UNII = 0T7J7SHH1H
| StdInChI=1S/Cl2Te/c1-3-2
| StdInChIKey = VXLPBEHPTWIBJR-UHFFFAOYSA-N
| SMILES=Cl[Te]Cl
}}
|Section2={{Chembox Properties
| Appearance= black solid{{cite book | last=Perry | first=Dale | title=Handbook of Inorganic Compounds | publisher=CRC Press | publication-place=Boca Raton, FL | year=2011 | isbn=978-1-4398-1462-8 | oclc=759865801}}
|Te=1|Cl=2
| SolubleOther=reacts with diethyl ether, insoluble in tetrachloromethane
}}
|Section8={{Chembox Related
| OtherAnions=Ditellurium bromide, {{chem2|Te2Br}}
| OtherCations=Dichlorine monoxide, {{chem2|OCl2}}
Sulfur dichloride, {{chem2|SCl2}}
Selenium dichloride, {{chem2|SeCl2}}
Polonium dichloride, {{chem2|PoCl2}}
| OtherCompounds=Tritellurium dichloride, {{chem2|Te3Cl2}}
Tellurium tetrachloride, {{chem2|TeCl4}}
}}
}}
Tellurium dichloride is a chloride of tellurium with the chemical formula TeCl2.
Preparation
Tellurium dichloride can be produced by reacting tellurium with difluorodichloromethane.{{cite book | last=Gmelin | first=Leopold | title=Tellurium | publisher=Springer-Verlag | year=1976 | oclc=77834357 | language=en, de}}{{cite journal | last=Aynsley | first=E. E. | title=598. The preparation and properties of tellurium dichloride | journal=Journal of the Chemical Society (Resumed) | publisher=Royal Society of Chemistry (RSC) | year=1953 | issn=0368-1769 | doi=10.1039/jr9530003016 | page=3016}}
It can also be produced by the comproportionation of tellurium and tellurium tetrachloride.{{cite book | last=Haaland | first=Arne | title=Molecules and models : the molecular structures of main group element compounds | publisher=Oxford University Press | publication-place=Oxford New York | year=2008 | isbn=978-0-19-152860-6 | oclc=226969121}}
Properties
Tellurium dichloride is a black solid that reacts with water. It melts into a black liquid and vapourizes into a purple gas.{{cite journal | last1=Fernholt | first1=Liv | last2=Haaland | first2=Arne | last3=Volden | first3=Hans V. | last4=Kniep | first4=Rüdiger | title=The molecular structure of tellurium dichloride, TeCl2, determined by gas electron diffraction | journal=Journal of Molecular Structure | publisher=Elsevier BV | volume=128 | issue=1–3 | year=1985 | issn=0022-2860 | doi=10.1016/0022-2860(85)85037-7 | pages=29–31| doi-access=free | bibcode=1985JMoSt.128...29F }} 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. 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).