Germanium dichloride

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Germanium dichloride
Names
Preferred IUPAC name
Germanium dichloride
Systematic IUPAC name
Dichlorogermanylidene
Other names
Dichlorogermylene

Germanium(II) chloride

Germanous chloride
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
100.030.162 Edit this at Wikidata
EC Number
  • 233-192-1
UNII
  • InChI=1S/Cl2Ge/c1-3-2
    Key: QHGIKMVOLGCZIP-UHFFFAOYSA-N
  • Cl[Ge]Cl
Properties
GeCl2
Molar mass 143.546 g/mol
Appearance white-pale yellow solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Germanium dichloride is a chemical compound of germanium and chlorine with the formula GeCl2. It is a yellow solid. Germanium dichloride is an example of a compound featuring germanium in the +2 oxidation state.

Preparation

Solid germanium dichloride can be produced by comproportionation by passing germanium tetrachloride, GeCl4, over germanium metal at 300 °C and reduced pressure (0.1 mmHg).[1]

GeCl4 + Ge → 2 GeCl2

Germanium dichloride is also formed from the decomposition of trichlorogermane, GeHCl3, at 70 °C. Trichlorogermane is generated when germanium reacts with hydrogen chloride.[1] This reaction involves dehydrohalogenation.

GeHCl3 → GeCl2 + HCl

Another route to germanium dichloride is the reduction of germanium tetrachloride with hydrogen at 800 °C.[1]

GeCl4 + H2 → GeCl2 + 2HCl

Reactions

GeCl2 is hydrolysed to give yellow germanium(II) hydroxide, which on warming gives brown germanium monoxide:[1]

GeCl2 + 2 H2O ⇌ Ge(OH)2(s) + 2 HCl
Ge(OH)2 → GeO + H2O

Alkalizing a solution containing germanium(II) ions:

Ge2+ + 2 OH → Ge(OH)2

Germanium oxides and hydroxides are amphoteric. Solutions of GeCl2 in HCl are strongly reducing.[2] With chloride ion, ionic compounds containing the pyramidal GeCl3 ion have been characterised, for example [3] With rubidium and caesium chloride compounds, e.g. RbGeCl3 are produced; these have distorted perovskite structures.[1]

Germanium dichloride reacts with tetraethylammonium chloride to give the trichlorogermanate:[4]

GeCl2 + Et4NCl → Et4NGeCl3

Dichlorogermylene

Molecular GeCl2 is often called dichlorogermylene, highlighting its resemblance to a

dioxane complex, GeCl2·dioxane, has been used as a source of molecular GeCl2 for reaction syntheses, as has the in situ reaction of GeCl4 and Ge metal. GeCl2 is quite reactive and inserts into many types of chemical bonds.[6] Usually, germanium dichloride is generated from germanium dichloride dioxane
.

References