Tellurium tetrachloride

Tellurium tetrachloride
IUPAC name

Tellurium(IV) chloride
Tetratellurium hexadecachloride
Other names

Tellurium chloride
Identifiers
CAS number 10026-07-0
PubChem 61443
ChemSpider 55367 Y
Jmol-3D images Image 1
Properties
Molecular formula [TeCl4]4
Molar mass 1077.64 g/mol
Appearance hygroscopic pale yellow solid
(if fused, maroon liquid)
Density 3.26 g/cm³, solid
Melting point

224 °C
Boiling point

380 °C
Structure
Crystal structure Monoclinic, mS80
Space group C12/c1, No. 15
Coordination
geometry		 Distorted octahedral (Te)
Molecular shape Seesaw (gas phase)
Dipole moment 2.59 D (gas phase)
Hazards
Main hazards Toxic, corrosive,
respiratory irritant
Related compounds
Other anions Tellurium tetrafluoride
Tellurium tetrabromide
Tellurium tetraiodide
Other cations Selenium tetrachloride
Polonium tetrachloride
Related compounds Tellurium dichloride
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Tellurium tetrachloride is the inorganic compound with the empirical formula TeCl4. The compound is volatile, subliming at 200 °C at 0.1 mm Hg[1]. Molten TeCl4 is ionic, dissociating into ions TeCl3+ and Te2Cl102−.[1]

Contents

Structure

TeCl4 is monomeric in the gas phase, with a structure similar to that of SF4.[2]. In the solid state, it is a tetrameric cluster, Te4Cl16. The cluster with a Te4Cl4 core and three terminal chloride ligands for each Te. Alternatively it 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

Synthesis

TeCl4 is prepared by chlorination of tellurium powder:

Te + 2 Cl2 → TeCl4

The reaction is initiated with heat. The product is isolated by distillation.[3]

Applications

TeCl4 has proven of occasional interest in organic synthesis.[4] 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 give TeCl2(C6H4OMe)2, which can be reduced to the diaryl telluride.

Safety considerations

As is the case for other tellurium compounds, TeCl4 is toxic. It also releases HCl upon hydrolysis.

References

  1. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 
  2. ^ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5 
  3. ^ Suttle, J. F.; Smith, C. R. F. (1950). "Tellurium(IV) chloride". Inorganic Syntheses 3: 140–2. doi:10.1002/9780470132340. ISBN 9780470131626. 
  4. ^ Petragnani, N.; Comasseto, J. V. Synthesis 1991, 793, 897