Bismuth tribromide

Bismuth tribromide
α polymorph	β polymorph
Names
	IUPAC name bismuth bromide
	Other names bismuth tribromide; tribromobismuth; tribromobismuthine; tribromobismuthane; bismuth(III) bromide
Identifiers
CAS Number	7787-58-8;
3D model (JSmol)	Interactive image;
ChemSpider	74210;
ECHA InfoCard	100.029.201
EC Number	232-121-1;
PubChem CID	82232;
UNII	DT59198T2X;
CompTox Dashboard (EPA)	DTXSID8064850 ;
	InChI InChI=1S/Bi.3BrH/h;31H/q+3;;;/p-3 Key: TXKAQZRUJUNDHI-UHFFFAOYSA-K; InChI=1/Bi.3BrH/h;31H/q+3;;;/p-3 Key: TXKAQZRUJUNDHI-DFZHHIFOAX;
	SMILES Br[Bi](Br)Br;
Properties
Chemical formula	BiBr3
Molar mass	448.692 g·mol−1
Appearance	white to light yellow or golden deliquescent crystals
Density	5.72 g/cm3 at 25 °C
Melting point	219 °C (426 °F; 492 K)
Boiling point	462 °C (864 °F; 735 K)
Solubility in water	Soluble, slow hydrolysis
Solubility	diethyl ether, THF
Magnetic susceptibility (χ)	-147.0·10−6 cm3/mol
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	−276
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	corrosive
	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
NFPA 704 (fire diamond)	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). 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]

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

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⁻, (BiBr⁻
₄)_n and (BiBr²⁻
₅)_n.^[4]

References

^ ^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.
^ "Sigma-Aldrich: 654981 Bismuth(III) bromide anhydrous, powder, 99.999% trace metals basis". Archived from the original on 2012-02-11.
^ 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.
^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 564–568. ISBN 978-0-08-037941-8.

[G&E-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.

[G&E2-4] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 564–568. ISBN 978-0-08-037941-8.

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