Titanium(III) iodide

Titanium(III) iodide is an inorganic compound with the formula TiI₃. It is a dark violet solid that is insoluble in solvents, except upon decomposition.

Titanium(III) iodide

Names
IUPAC name Titanium(III) iodide
Other names Titanium triiodide
Identifiers
CAS Number	13783-08-9 Y
3D model (JSmol)	Interactive image
PubChem CID	18955717
CompTox Dashboard (EPA)	DTXSID001314238
InChI InChI=1S/3HI.Ti/h3*1H;/q;;;+3/p-3 Key: HUYLAMJIPCOVOM-UHFFFAOYSA-K
SMILES I[Ti](I)I
Properties
Chemical formula	I3Ti
Molar mass	428.580 g·mol−1
Appearance	black-violet solid
Density	4.96 g·cm−3[1]
Related compounds
Other anions	Titanium(III) fluoride Titanium(III) bromide Titanium(III) chloride
Other cations	Zirconium(III) iodide Hafnium(III) iodide
Related compounds	Titanium(IV) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation and structure

Titanium(III) iodide can be prepared by reaction of titanium with iodine:^[2]

2 Ti + 3 I₂ → 2 TiI₃

It can also be obtained by reduction of TiI₄, e.g., with aluminium.^[3]

In terms of its structure, the compound exists as a polymer of face-sharing octahedra. Above 323 K, the Ti---Ti spacings are equal, but below that temperature, the material undergoes a phase transition. In the low temperature phase, the Ti---Ti contacts are alternating short and long. The low temperature structure is similar to that of molybdenum tribromide.^[1]