Iron (III) bromide

Crystal structure
__ Fe 3+      __ Br -
Crystal system	trigonal
Space group	R 3 (No. 148)
Lattice parameters	a = 639.7 pm c = 1837.5 pm
Coordination numbers	Fe [6], Br [2]
General
Surname	Iron (III) bromide
other names	Iron tribromide Iron bromide (ambiguous) Ferrum bromatum (ambiguous)
Ratio formula	FeBr 3
Brief description	brown-red crystalline solid
External identifiers / databases
CAS number 10031-26-2 EC number 233-089-1 ECHA InfoCard 100.030.069 PubChem 25554 Wikidata Q415791
properties
Molar mass	295.56 g mol −1
Physical state	firmly
density	4.5 g cm −3
Melting point	200 ° C (decomposition)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
Thermodynamic properties
ΔH f 0	−268 kJ mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Iron (III) bromide is a chemical compound of iron and is one of the bromides .

Extraction and presentation

Iron (III) bromide can be produced by reacting iron with bromine .

${\displaystyle {\ce {2Fe + 3Br2 -> 2FeBr3}}}$

It can also be obtained from the processing of potash salts .

properties

Iron (III) bromide decomposes at temperatures> 200 ° C to iron (II) bromide and bromine. The reaction is reversible at a lower temperature.

${\displaystyle {\ce {2FeBr3 -> 2FeBr2 + Br2}}}$

Iron (III) bromide crystallizes in the trigonal crystal system with the space group R 3 (space group no. 148) . The lattice constants are a = 639.7 pm and c = 1837.5 pm.

use

Iron bromide is used as a catalyst ( Lewis acid ) in aromatic substitutions (e.g. electrophilic aromatic substitution , bromination of benzene ).

Individual evidence

1. ↑ ^{a b c} iron tribromide at WebElements .
2. ↑ ^{a b} Data sheet Iron (III) bromide from Sigma-Aldrich , accessed on March 29, 2011 ( PDF ).
3. ^ AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 2: Subgroup elements, lanthanoids, actinides, transactinides. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049590-4 , p. 1949 (Reading sample: Part C - Subgroup elements. Google book search ).
4. ↑ Georg Brauer (ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1643.
5. ^ Potash salt storage in Uzbekistan ( Memento from January 19, 2012 in the Internet Archive ).
6. ↑ M. Armbruster, Th. Ludwig, HW Rotter, G. Thiele, H. Oppermann: About iron tribromide: Investigations of equilibria, crystal structure and spectroscopic characterization. In: Z. anorg. allg. Chem. 626, 2000, pp. 187-195. doi : 10.1002 / (SICI) 1521-3749 (200001) 626: 1 <187 :: AID-ZAAC187> 3.0.CO; 2-X
7. ↑ Hermann Bünte, Klaus Bünte: The spectrum of medicine: illustrated manual from the basics to the clinic . Schattauer Verlag, 2004, ISBN 3-7945-2374-1 , p. 154 ( limited preview in Google Book search).