Tellurium tetrachloride
Encyclopedia
Tellurium tetrachloride is the inorganic compound
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

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

Structure

TeCl4 is monomeric in the gas phase, with a structure similar to that of SF4
Sulfur tetrafluoride
Sulfur tetrafluoride is the chemical compound with the formula SF4. This species exists as a gas at standard conditions. It is a corrosive species that releases dangerous HF upon exposure to water or moisture...

.. In the solid state, it is a tetramer
Tetramer
A tetramer is a protein with four subunits . There are homotetramers such as glutathione S-transferase or single-strand binding protein, dimers of hetero-dimers such as hemoglobin , and heterotetramers, where each subunit is different.-Subunit interactions in tetramers:The interactions between...

ic 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
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...

 of tellurium powder:
Te + 2 Cl2 → TeCl4

The reaction is initiated with heat. The product is isolated by distillation.

Applications

TeCl4 has proven of occasional interest in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

. 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
Anisole
Anisole, or methoxybenzene, is the organic compound with the formula CH3OC6H5. It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances...

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.
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