Chemistry:Bismuth tribromide

From HandWiki
Bismuth tribromide
Bismuth bromide
Alpha-bismuth(III)-bromide-xtal-2x2x2-c-3D-bs-17.png
α polymorph
Beta-bismuth(III)-bromide-xtal-layer-c-rot-3D-bs-17.png
β polymorph
Names
IUPAC name
bismuth bromide
Other names
bismuth tribromide
tribromobismuth
tribromobismuthine
tribromobismuthane
bismuth(III) bromide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 232-121-1
UNII
Properties
BiBr3
Molar mass 448.692 g·mol−1
Appearance white to light yellow or golden deliquescent crystals[1]
Density 5.72 g/cm3 at 25 °C[1]
Melting point 219 °C (426 °F; 492 K) [1]
Boiling point 462 °C (864 °F; 735 K) [1]
Soluble, slow hydrolysis
Solubility diethyl ether, THF
-147.0·10−6 cm3/mol
Thermochemistry
−276[1]
Hazards
Main hazards corrosive[2]
GHS pictograms GHS05: Corrosive
GHS Signal word Danger
H314
P260, P264, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
3
1
Related compounds
Other anions
bismuth trifluoride
bismuth trichloride
bismuth triiodide
Other cations
nitrogen tribromide
phosphorus tribromide
arsenic tribromide
antimony tribromide
aluminium tribromide
iron(III) bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Bismuth tribromide is an inorganic compound of bismuth and bromine with the chemical formula BiBr3.

Preparation

It may be formed by the reaction of bismuth oxide and hydrobromic acid.[1]

Bi
2
O
3
+ 6 HBr ⇌ 2 BiBr
3
+ 3 H
2
O

Bismuth tribromide can also be produced by the direct oxidation of bismuth in bromine.[1]

2 Bi + 3 Br
2
→ 2 BiBr
3

Structure

Bismuth tribromide adopts two different structures in the solid state: a low-temperature polymorph α-BiBr3 that is stable below 158 °C and a high-temperature polymorph β-BiBr3 that is stable above this temperature. Both polymorphs are monoclinic, but α-BiBr3 is in space group P21/a whereas β-BiBr3 is in C2/m. α-BiBr3 consists of pyramidal molecules whereas β-BiBr3 is polymeric and adopts the AlCl3 structure. BiBr3 is the only group 15 trihalide that can adopt both molecular and polymeric structures.[3]

Reactivity

Bismuth bromide is highly water-soluble. It is a Lewis acid and accepts bromide ions to form monomeric and oligomeric anionic complexes (bromobismuthates), e.g. [BiBr6]3−, [Bi2Br10]4−, (BiBr4)n and (BiBr2−5)n.[4]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 558-561. ISBN 978-0-08-037941-8. 
  2. "Sigma-Aldrich: 654981 Bismuth(III) bromide anhydrous, powder, 99.999% trace metals basis". Archived from the original on 2012-02-11. https://web.archive.org/web/20120211185950/http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en#x7C;ALDRICH&=N5&. 
  3. von Benda, Heike (1980). "Zur Polymorphie des Wismuttribromids". Zeitschrift für Kristallographie - Crystalline Materials 151 (1–4): 271–286. doi:10.1524/zkri.1980.151.14.271. 
  4. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 564-568. ISBN 978-0-08-037941-8.