Germanium(IV) iodide

Germanium(IV) iodide is an inorganic compound with the chemical formula GeI4.

Preparation
Germanium(IV) iodide can be obtained by the reaction of germanium and iodine or the reaction of germanium dioxide and 57% hydriodic acid:


 * GeO2 + 4 HI -> GeI4 + 2 H2O

Chemical properties
Germanium(IV) iodide reacts with tetraalkyl tin at 250 °C to form R2SnI2 and R2GeI2 (R= Et, Bu, Ph). It reacts with germanium and sulfur at high temperatures to produce red GeSI2 and orange Ge2S3I2. It reacts with diiron nonacarbonyl in an ionic liquid ([BMIm]Cl/AlCl3) at 130 °C to obtain Ge12[Fe(CO)3]8I4.


 * 12 GeI4 + 15 Fe2(CO)9 -> Ge12[Fe(CO)3]8I4 + 22 FeI2 + 111 CO↑

Physical properties
Germanium(IV) iodide is an orange-red crystalline solid that hydrolyzes in water. It is soluble in carbon disulfide and benzene, but less soluble in carbon tetrachloride and chloroform. It begins to decompose into germanium(II) iodide and iodine above its melting point. Germanium(IV) iodide crystallizes in the cubic crystal system, space group Pa$\overline{3}$ (space group no. 205), with the lattice parameter a = 11.89 Å. The crystal structure consists of tetrahedral GeI4 molecules.