Titanium(III) triiodide Chemical Properties

color 

violet crystals, crystalline

Titanium(III) triiodide Usage And Synthesis

Chemical Properties

Titanium (III) iodide is a violet-black needle-shaped crystals; stable up to 300℃ on heating in high vacuum; decomposes to Til2 + Til4 above 350℃. Dissolves slowly in H2O without evolving H2.

Synthesis

Direct synthesis from stoichiometric quantities of the elements by heating in a sealed tube is similar to the preparation of TiCl3 or TiCl2 from Ti + TiCl4. As long as the tetraiodide still accompanies the diiodide and the triiodide, the product is a solid cake which is difficult to break up by tapping. Toward the end of the reaction, after heating for several hours at 700℃, the product can be pulverized by vigorous shaking. The reaction may be completed at 180℃ (reduce the temperature over a period of several days). The reaction is tested for completion by pulling out the tip of the tube from the furnace (maintained at this temperature) and cooling it with a piece of moist filter paper. The reaction is complete if after several hours only a very slight film of Til4 is observed.