Germanium(II) iodide is an iodide of

germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors s ...

, with the chemical formula of GeI₂.

Preparation

Germanium(II) iodide can be produced by reacting

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: : Chemical ...

with

hydriodic acid Hydroiodic acid (or hydriodic acid) is an aqueous solution of hydrogen iodide (HI). It is a strong acid, one that is ionized completely in an aqueous solution. It is colorless. Concentrated solutions are usually 48% to 57% HI. Reactions Hydr ...

and

hypophosphorous acid Hypophosphorous acid (HPA), or phosphinic acid, is a phosphorus oxyacid and a powerful reducing agent with molecular formula H3PO2. It is a colorless low-melting compound, which is soluble in water, dioxane and alcohols. The formula for this ...

and

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

Georg Brauer Georg Karl Brauer (born 11. April 1908 in Bochum, died 26. February 2001 in Freiburg im Breisgau) was a German chemist. Life Brauer was the son of the chemist Eberhard Brauer and Elisabeth Brauer, a daughter of Wilhelm Ostwald. From 1926 to 1932 ...

(Hrsg.), unter Mitarbeit von

Marianne Baudler Marianne Baudler (27 April 1921 – 5 March 2003) was a German chemist. She is known for her research on phosphorus. Life Marianne Baudler was born in Stettin. She started studying Chemistry at the TH Dresden in April 1940 and finished her studi ...

u. a.: ''Handbuch der Präparativen Anorganischen Chemie.'' 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 727. : It can also be formed by the reaction of

germanium monosulfide Germanium monosulfide or Germanium(II) sulfide is the chemical compound with the formula Ge S. It is a chalcogenide glass and a semiconductor. Germanium sulfide is described as a red-brown powder or black crystals. Germanium(II) sulfide when dry ...

germanium monoxide Germanium monoxide, GeO, is a chemical compound of germanium and oxygen. It can be prepared as a yellow sublimate at 1000 °C by reacting GeO2 with Ge metal. The yellow sublimate turns brown on heating at 650 °C. GeO is not well charact ...

and

hydrogen iodide Hydrogen iodide () is a diatomic molecule and hydrogen halide. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid. Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under sta ...

. : :} It can also be produced from the direct reaction of germanium and iodine at 200 – 400 °C: : Germanium(II) iodide can also be formed from the decomposition of HGeI₃, which can be prepared by reacting HGeCl₃ with hydroiodic acid: : :

Properties

Germanium(II) iodide is a yellow crystal that slowly hydrolyzes into germanium(II) hydroxide in the presence of moisture. It is insoluble in

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...

and slightly soluble in

chloroform Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...

and

carbon tetrachloride Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...

. It has a cadmium iodide structure with

lattice parameter A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has o ...

s a = 413 pm and c = 679 pm. It disproportionates to germanium and germanium tetraiodide at 550 °C.

Applications

Germanium(II) iodide can react with

carbene In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is or where the R represents substituents or hydrogen atoms. The term "carbene" ma ...

to form stable compounds. It is also used in the electronics industry to produce germanium layers epitaxially through

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can b ...

reactions.

References

{{Iodides Germanium compounds Iodides