Germanium(II) hydroxide

Germanium(II) hydroxide, normally written as Ge(OH)₂ is a poorly characterised compound sometimes called hydrous germanium(II) oxide or germanous hydroxide. It was first reported by Winkler in 1886.

Germanium(II) hydroxide is formed as a white or yellow precipitate when base is added to solutions containing Ge^II produced for example by the reduction of an acid solution of GeO₂, germanium dioxide with H₃PO₂, hypophosphorous acid or alternatively by hydrolysis of GeCl₂ The initial precipitate, which has no definite stoichiometry, can be represented by GeO.xH₂O, Ge(OH)₂.xH₂O or loosely Ge(OH)₂ and is only slightly soluble in water or alkali and is not appreciably soluble in perchloric acid, HClO₄. It is soluble in hydrochloric acid,HCl. On digestion with sodium hydroxide, NaOH it yields a brown insoluble compound which after drying in vacuo forms a brown pyrophoric substance with the approximate stoichiometry of (HGe)₂O₃. On the basis of the infrared spectrum (HGe)₂O₃ may contain a germanium hydrogen bond, Ge-H.

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