Germanium dichloride


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

Preparation

Solid GeCl2 can be produced by passing germanium tetrachloride, GeCl4, over Ge metal at 650 °C.
It is also formed from the decomposition of chlorogermane, GeH3Cl, at 70 °C.

Reactions

GeCl2 is hydrolysed to give yellow germanium hydroxide, which on warming gives brown germanium monoxide:
Alkalizing a solution containing germanium ions:
Ge2+ + 2OH− = Ge2
Germanium oxides and hydroxides are amphoteric.
Solutions of GeCl2 in HCl are strongly reducing. With chloride ion, ionic compounds containing the pyramidal GeCl3− ion have been characterised, for example With rubidium and caesium chloride compounds, e.g.RbGeCl3 are produced; these have distorted perovskite structures.

Molecular GeCl2, dichlorogermylene

Molecular GeCl2 is often called dichlorogermylene, highlighting its resemblance to a carbene. The structure of gas-phase molecular GeCl2 shows that it is a bent molecule, as predicted by VSEPR theory. The 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 different types of chemical bonds.