Germanium (II) bromide

Crystal structure
__ Ge 2+      __ Br -
Crystal system	monoclinic
Space group	P 2 1 / c (No. 14)
Lattice parameters	a  = 11.68  Å , b  = 9.12 Å, c  = 7.02 Å, β  = 101.9 °
General
Surname	Germanium (II) bromide
other names	Germanium dibromide
Ratio formula	GeBr 2
Brief description	white to pale yellow solid
External identifiers / databases
CAS number 24415-00-7 EC number 627-437-5 ECHA InfoCard 100.155.797 PubChem 6327224 Wikidata Q3545919
properties
Molar mass	232.45 g mol −1
Physical state	firmly
Melting point	120-125 ° C 143–144 ° C (with rapid heating)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 314 P: 280-305 + 351 + 338-310
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Germanium (II) bromide is an inorganic chemical compound of germanium from the group of bromides .

Extraction and presentation

Germanium (II) bromide can be obtained by reacting germanium (IV) bromide with germanium or zinc .

${\displaystyle {\ce {Ge + GeBr4 -> 2GeBr2}}}$

It can also be represented by thermal dissociation of Tribromgerman in a vacuum or by concentrating a solution of germanium (II) oxide in 46 percent hydrobromic acid . It can also be obtained as a residue from the distillation of a solution of Tribromgerman in hydrobromic acid or as a residue from the distillation of an ethereal solution of GeHBr ₃ - (C ₂ H ₅ ) ₂ O obtainable from germanium (II) oxide with 40% hydrogen bromide in ether . First, germanium (II) bromide was produced by reacting germanium with hydrogen bromide and then reducing the resulting mixture of GeBr ₄ and GeHBr ₃ with metallic zinc.

properties

Germanium (II) bromide is a polymeric colorless to pale yellow solid that is soluble in ethanol and acetone . At 180–220 ° C, oxidation occurs in air. When heated in non-polar solvents, it disproportionates to germanium (IV) bromide and subbromides; when heated dry, germanium (IV) bromide and germanium are formed. With water it hydrolyzes to germanium (II) hydroxide . Germanium (II) bromide crystallizes in a monoclinic structure, space group P 2 ₁ / c (space group no. 14) , with the lattice parameters a  = 11.68  Å , b  = 9.12 Å, c  = 7.02 Å and β  = 101.9 °. In the crystal structure, each germanium atom is bound to three bromine atoms, two of which bind to other germanium atoms, resulting in a chain structure.

Individual evidence

1. ↑ ^{a b c d e} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 724.
2. ↑ ^{a b c d} data sheet germanium (II) bromide, 97% from Sigma-Aldrich , accessed on May 9, 2017 ( PDF ).
3. ^ ^{A b} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 959.
4. ↑ ^{a b} L. M. Dennis: Germanium. Summary of studies in the Department of Chemistry, Cornell University, 1921-1927 . In: Journal for inorganic and general chemistry . tape 174 , no. 1 , August 2, 1928, p. 97 , doi : 10.1002 / zaac.19281740114 .
5. ↑ RC Rouse, DR Peacor, BR Maxim: The crystal structure of germanium dibromide. In: Zeitschrift für Kristallographie , 145, 1977, pp. 161-171.