Tellurium tetrachloride

Tellurium tetrachloride is a covalent compound of tellurium and chlorine that is somewhat volatile, subliming at 200 °C at 0.1 mmHg. It exists as the tetramer in the solid state, a Te4 tetrahedron with face-capping chlorines and three terminal chlorines per tellurium atom. It forms dimers and monomers in the liquid and gas. Presumably, the monomer adopts the structure of SF4.

TeCl4 has proven of occasional interest in organic synthesis. 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 TeC2(C6H4OMe)2 which can be reduced to the diaryl telluride.

Safety considerations
As is the case for other tellurium compounds, TeCl4 is toxic and should be handled in a fume cupboard. It also releases HCl upon hydrolysis.