Tellurium tetrachloride

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Tellurium tetrachloride
Tellurium tetrachloride
Names
IUPAC names
Tellurium(IV) chloride
Tetratellurium hexadecachloride
Other names
Tellurium chloride
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.030.038
UNII
Properties
[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 (435 °F; 497 K)
Boiling point 380 °C (716 °F; 653 K)
Structure
Monoclinic, mS80
C12/c1, No. 15
Distorted octahedral (Te)
Seesaw (gas phase)
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
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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]

Structure[edit]

TeCl4 is monomeric in the gas phase, with a structure similar to that of SF4.[2] In the solid state, it is a tetrameric cubane-like 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

Tellurium-tetrachloride-GED-1997-3D-balls.png Tellurium-tetrachloride-tetramer-from-xtal-2000-3D-balls.png

Synthesis[edit]

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[edit]

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[edit]

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

References[edit]

  1. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9. 
  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). Audrieth, Ludwig F., ed. "Tellurium(IV) chloride". Inorganic Syntheses. Inorganic Syntheses. 3: 140–2. doi:10.1002/9780470132340. ISBN 978-0-470-13162-6. 
  4. ^ Petragnani, N.; Comasseto, J. V. (1991). "Tellurium Reagents in Organic Synthesis; Recent Advances. Part 1". Synthesis (10): 793–817. doi:10.1055/s-1991-26577.  and Petragnani, N.; Comasseto, J. V. (1991). "Tellurium Reagents in Organic Synthesis; Recent Advances. Part 2". Synthesis (11): 897–919. doi:10.1055/s-1991-26605.