Germanium tetrabromide

Germanium tetrabromide
Names

IUPAC name tetrabromogermane
Identifiers
CAS Number	13450-92-5^Y
3D model (JSmol)	Interactive image
ChemSpider	24230
ECHA InfoCard	100.033.270
EC Number	236-612-1
PubChem CID	26011
CompTox Dashboard (EPA)	DTXSID2065468
InChI InChI=1S/Br4Ge/c1-5(2,3)4 Key: VJHDVMPJLLGYBL-UHFFFAOYSA-N
SMILES [Ge](Br)(Br)(Br)Br
Properties
Chemical formula	Br₄Ge
Molar mass	392.246 g·mol⁻¹
Appearance	Colorless solid
Density	2.123 g/cm³
Melting point	26 °C (79 °F; 299 K)
Boiling point	185.9 °C (366.6 °F; 459.0 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
Structure^[1]
Crystal structure	α-Cubic (SnI₄ type) β-Monoclinic (SnBr₄ type)
Thermochemistry
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	83.3 kcal/mol
Related compounds
Other anions	Germanium tetrafluoride Germanium tetrachloride Germanium tetraiodide
Other cations	Carbon tetrabromide Silicon tetrabromide Tin(IV) bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

Germanium tetrabromide is the inorganic compound with the formula GeBr₄. It is a colorless solid that melts near room temperature. It can be formed by treating solid germanium with bromine, or by treating a germanium-copper mixture with bromine:^[2]

Ge + Br₂ → GeBr₄

From this reaction, GeBr₄ has a heat of formation of 83.3 kcal/mol.^[3]

The compound is liquid at 25 °C, and forms an interlocking liquid structure.^[4] From room temperature down to −60 °C the structure takes on a cubic α form, whereas at lower temperatures it takes on a monoclinic β form.

References

^ Köhler, J.; Okudera, Η.; Simon, A. (2005). "Crystal structure of germanium tetrabromide, β-GeBr4, low temperature modification". Zeitschrift für Kristallographie - New Crystal Structures. 220 (1–4). Walter de Gruyter GmbH: 554. doi:10.1524/ncrs.2005.220.14.554. ISSN 2197-4578.
^ P. W. Schenk (1963). "Silicon and Germanium". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2page=718. NY, NY: Academic Press.
^ Evans, D. F.; Richards, R. E. (1952). "233. The heats of formation of germanium tetrabromide and germanium tetraiodide". Journal of the Chemical Society (Resumed). Royal Society of Chemistry (RSC): 1292. doi:10.1039/jr9520001292. ISSN 0368-1769.
^ Swamy, K. N.; Bhuiyan, L. B. (1980). "The Reference Interaction Site Model and the Structure of Liquid Germanium Tetrabromide". Physics and Chemistry of Liquids. 9 (2). Informa UK Limited: 169–174. doi:10.1080/00319108008084774. ISSN 0031-9104.