Germanium(II) iodide is an iodide of germanium, with the chemical formula of GeI2.

Germanium(II) iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.620 Edit this at Wikidata
EC Number
  • 236-998-1
  • I[Ge]I
Properties
GeI2
Molar mass 326.439 g·mol−1
Appearance yellow solid[1]
Density 5.37 g·cm−3 (25 °C)[2]
Melting point 428 °C[3]
Boiling point 550 °C (decomposes)[3]
Structure
P3m1 (No. 164)[4]
Related compounds
Other anions
germanium(II) fluoride
germanium(II) chloride
germanium(II) bromide
Other cations
tin(II) iodide
lead(II) iodide
Related compounds
germanium(IV) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation

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Germanium(II) iodide can be produced by reacting germanium(IV) iodide with hydriodic acid and hypophosphorous acid and water:[1]

GeI4 + H2O + H3PO2 → GeI2 + H3PO3 + 2 HI

It can also be formed by the reaction of germanium monosulfide or germanium monoxide and hydrogen iodide.[1]

GeO + 2 HI → GeI2 + H2O
GeS + 2 HI → GeI2 + H2S}

It can also be produced from the direct reaction of germanium and iodine at 200 – 400 °C:[1]

Ge + I2 → GeI2

Germanium(II) iodide can also be formed from the decomposition of HGeI3, which can be prepared by reacting HGeCl3 with hydroiodic acid:[5]

HGeCl3 + 3 HI → HGeI3 + HCl
HGeI3 → GeI2 + HI

Properties

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Germanium(II) iodide is a yellow crystal that slowly hydrolyzes into germanium(II) hydroxide in the presence of moisture. It is insoluble in hydrocarbons and slightly soluble in chloroform and carbon tetrachloride. It has a cadmium iodide structure with lattice parameters a = 413 pm and c = 679 pm.[1] It disproportionates to germanium and germanium tetraiodide at 550 °C.[6]

Applications

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Germanium(II) iodide can react with carbene to form stable compounds.[2] It is also used in the electronics industry to produce germanium layers epitaxially through disproportionation reactions.[7]

References

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  1. ^ a b c d e Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 727.
  2. ^ a b Sigma-Aldrich Co., product no. {{{id}}}.
  3. ^ a b William M. Haynes (2012), CRC Handbook of Chemistry and Physics, 93rd Edition, CRC Press, pp. 4–65, ISBN 978-143988049-4
  4. ^ Jean d’Ans, Ellen Lax, Roger Blachnik (1998), Taschenbuch für Chemiker und Physiker, Springer DE, p. 472, ISBN 364258842-5{{citation}}: CS1 maint: multiple names: authors list (link)
  5. ^ Wolfgang Kirmse (2013), Carbene Chemistry 2e, Elsevier, p. 540, ISBN 978-032316145-9
  6. ^ Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, p. 959, ISBN 0-12-352651-5
  7. ^ A.G. Milnes (1972), Heterojunctions and Metal Semiconductor Junctions, Elsevier, p. 104, ISBN 032314136-6