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

Bismuth tribromide
Bismuth bromide
α polymorph
β polymorph
Names
IUPAC name
bismuth bromide
Other names
bismuth tribromide
tribromobismuth
tribromobismuthine
tribromobismuthane
bismuth(III) bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.201 Edit this at Wikidata
EC Number
  • 232-121-1
UNII
  • InChI=1S/Bi.3BrH/h;3*1H/q+3;;;/p-3
    Key: TXKAQZRUJUNDHI-UHFFFAOYSA-K
  • InChI=1/Bi.3BrH/h;3*1H/q+3;;;/p-3
    Key: TXKAQZRUJUNDHI-DFZHHIFOAX
  • Br[Bi](Br)Br
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
Occupational safety and health (OHS/OSH):
Main hazards
corrosive[2]
GHS labelling:
GHS05: Corrosive
Danger
H314
P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
0
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).

Preparation edit

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

Bi2O3 + 6 HBr ⇌ 2 BiBr3 + 3 H2O

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

2 Bi + 3 Br2 → 2 BiBr3

Structure edit

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 edit

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−, (BiBr
4
)n and (BiBr2−
5
)n.[4]

References edit

  1. ^ a b c d e f g 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.
  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. S2CID 96552131.
  4. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 564–568. ISBN 978-0-08-037941-8.