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| Names | |
|---|---|
| IUPAC names Tellurium(IV) chloride Tetratellurium hexadecachloride | |
| Other names Tellurium chloride | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider |
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| ECHA InfoCard | 100.030.038 |
| UNII | |
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| Properties | |
| TeCl4 | |
| Molar mass | 269.41 g/mol |
| Appearance | hygroscopic pale yellow solid (if fused, maroon liquid) |
| Density | 3.26 g/cm3, solid |
| Melting point | 224 °C (435 °F; 497 K) |
| Boiling point | 380 °C (716 °F; 653 K) |
| hot sulfur chloride[1] | |
| Structure | |
| Monoclinic,mS80 | |
| C12/c1, No. 15 | |
| Distorted octahedral (Te) | |
| Seesaw (gas phase) | |
| 2.59D (gas phase) | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Toxic, corrosive, respiratory irritant |
| Related compounds | |
Otheranions | Tellurium tetrafluoride Tellurium tetrabromide Tellurium tetraiodide |
Othercations | Selenium tetrachloride Polonium tetrachloride |
Related compounds | Tellurium dichloride |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Tellurium tetrachloride is theinorganic compound with theempirical formula TeCl4. The compound is volatile, subliming at 200 °C at 0.1 mmHg.[2] Molten TeCl4 is ionic, dissociating into TeCl3+ and Te2Cl102−.[2]
TeCl4 is monomeric in the gas phase, with a structure similar to that ofSF4.[3] In the solid state, it is atetramericcubane-type cluster, consisting of a Te4Cl4 core and three terminal chloride ligands for each Te. Alternatively, this tetrameric structure can be considered as a Te4 tetrahedron with face-capping chlorines and three terminal chlorines per tellurium atom, giving each tellurium atom a distorted octahedral environment
TeCl4 is prepared bychlorination oftellurium powder:
The reaction is initiated with heat. The product is isolated by distillation.[4]Crude TeCl4 can be purified by distillation under an atmosphere of chlorine.[1]
Alternatively TeCl4 can be prepared using sulfuryl chloride (SO₂Cl₂) as a chlorine source.[1] Yet another method involves the reaction of tellurium withsulfur monochloride (S2Cl2) at room temperature. This exothermic reaction rapidly forms white needle-like crystals of TeCl4.[5]
Tellurium tetrachloride is the gateway compound for high valentorganotellurium compounds. Arylation gives, depending on conditions,Te(C6H4R)2Cl2, [Te(C6H4R)5]−, [Te(C6H4R)6]2−.[6]
TeCl4 has few applications in organic synthesis. Its equivalent weight is high, and the toxicity of organotellurium compounds is problematic. Possible applications of tellurium tetrachloride toorganic synthesis have been reported.[7] It adds to alkenes to give Cl-C-C-TeCl3 derivatives, wherein the Te can be subsequently removed with sodium sulfide. Electron-rich arenes react to give aryl Te compounds. Thus,anisole gives TeCl2(C6H4OMe)2, which can be reduced to the diaryl telluride. TeCl4 is a precursor to tellurium-containingheterocycles liketellurophenes.[1]
Heating a mixture of TeCl4 and metallic tellurium givestellurium dichloride (TeCl2).[8]
In moist air, TeCl4 forms tellurium oxychloride (TeOCl2), which further decomposes with excess water to formtellurous acid (H2TeO3).[8]
As is the case for other tellurium compounds, TeCl4 is toxic. It also releases HCl upon hydrolysis.[1]
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