Germanium iodides

Germanium iodides are inorganic compound with the formula GeI_x. Two such compounds exist: germanium(II) iodide, GeI₂, and germanium(IV) iodide GeI₄.^[1]

Germanium(II) iodide is an orange-yellow crystalline solid which decomposes on melting. Its specific density is 5.37 and it can be sublimed at 240 °C in a vacuum. It can be prepared by reducing germanium(IV) iodide with aqueous hypophosphorous acid in the presence of hydroiodic acid.^[2] It is oxidised by a solution of potassium iodide in hydrochloric acid to germanium(IV) iodide. It reacts with acetylene at 140 °C to form an analogue of cyclohexa-1,4-diene in which the methylene groups, CH₂, are replaced with diiodogermylene groups, GeI₂.^[3]

Germanium(IV) iodide is an orange-red crystalline solid with melting point 144 °C and boiling point 440 °C (with decomposition). Its specific density is 4.32. It is soluble in non-polar solvents like carbon disulfide, chloroform or benzene,^[2] but hydrolyses readily.^[3]

Mixed anion compound germanide iodides are also known.

References

1. Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton, Florida: CRC Press. ISBN 0-8493-0486-5.
2. Schenk, P.W. (1963). "12. Silicon and Germanium". In Brauer, Georg (ed.). Handbook of preparative inorganic chemistry (Second ed.). Academic Press. p. 719-720. doi:10.1016/B978-0-12-395590-6.50020-X. ISBN 978-0-12-395590-6.
3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 376–377. ISBN 978-0-08-037941-8.