Tin(IV) iodide

Tin(IV) iodide, also known as stannic iodide, is the chemical compound with the formula SnI4. This tetrahedral molecule crystallizes as a bright orange solid that dissolves readily in nonpolar solvents such as benzene.

Preparation
The compound is usually prepared by the reaction of iodine and tin:


 * Sn + 2I2 -> SnI4

Chemical properties
The compound hydrolyses in water. In aqueous hydroiodic acid, it reacts to form a rare example of a hexaiodometallate:
 * SnI4 +  2 I−  →   [SnI6]2−

Physical properties
Tin(IV) iodide is an orange solid under standard conditions. It has a cubic crystal structure with the space group Pa$\overline{3}$ (space group no. 205), the lattice parameter a = 1226 pm and eight formula units per unit cell. This corresponds approximately to a cubic close packing of iodine atoms in which 1/8 of all tetrahedral gaps are occupied by tin atoms. This leads to discrete tetrahedral SnI4 molecules.