Germanium dichloride is a chemical compound of

germanium Germanium is a chemical element; it has Symbol (chemistry), symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid or a nonmetal in the carbon group that is chemically ...

and

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

with the formula . It is a yellow solid. Germanium dichloride is an example of a compound featuring germanium in the +2

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...

Preparation

Solid germanium dichloride can be produced by

comproportionation Comproportionation or symproportionation is a chemical reaction where two reactants containing the same element but with different oxidation numbers, form a compound having an intermediate oxidation number. It is the opposite of disproportionatio ...

by passing

germanium tetrachloride Germanium tetrachloride is a colourless, fuming liquid with a peculiar, acidic odour. It is used as an intermediate in the production of purified germanium metal. In recent years, GeCl4 usage has increased substantially due to its use as a reagent ...

, , over germanium metal at 300 °C and reduced pressure (0.1 mmHg). : Germanium dichloride is also formed from the decomposition of trichlorogermane, , at 70 °C. Trichlorogermane is generated when germanium reacts with hydrogen chloride. This reaction involves

dehydrohalogenation In chemistry, dehydrohalogenation is an elimination reaction which removes a hydrogen halide from a substrate (chemistry), substrate. The reaction is usually associated with the synthesis of alkenes, but it has wider applications. Dehydrohalogen ...

. : Another route to germanium dichloride is the reduction of germanium tetrachloride with

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

at 800 °C. :

Reactions

is hydrolysed to give yellow germanium(II) hydroxide, which on warming gives brown germanium monoxide: : : Alkalizing a solution containing germanium(II) ions: : Germanium oxides and hydroxides are amphoteric. Solutions of in HCl are strongly reducing.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier With chloride ion, ionic compounds containing the pyramidal ion have been characterised, for example With rubidium and caesium chloride compounds, e.g. are produced; these have distorted

perovskite Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (stru ...

structures. Germanium dichloride reacts with

tetraethylammonium chloride Tetraethylammonium chloride (TEAC) is a quaternary ammonium compound with the chemical formula , sometimes written as . In appearance, it is a hygroscopic, colorless, crystalline solid. It has been used as the source of tetraethylammonium ions in ...

to give the trichlorogermanate: :

Dichlorogermylene

Molecular is often called dichlorogermylene, highlighting its resemblance to a

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

. The structure of gas-phase molecular shows that it is a bent molecule, as predicted by

VSEPR Valence shell electron pair repulsion (VSEPR) theory ( , ) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theor ...

theory. The

dioxane Dioxane may refer to the following chemical compounds: * 1,2-dioxane * 1,3-dioxane * 1,4-dioxane {{Authority control ...

complex, , has been used as a source of molecular for reaction syntheses, as has the ''in situ'' reaction of and Ge metal. is quite reactive and inserts into many types of chemical bonds. Usually, germanium dichloride is generated from germanium dichloride dioxane.

References

{{Chlorides Germanium(II) compounds Chlorides Metal halides Nonmetal halides