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;
PubChemCID	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	448.692g·mol−1
Appearance	white to light yellow or golden deliquescent crystals
Density	5.72 g/cm3at 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)	-147.0·10−6cm3/mol
Thermochemistry
Std enthalpy of; formation(ΔfH⦵298)	−276
Hazards
	Occupational safety and health(OHS/OSH):
Main hazards	corrosive
	GHSlabelling:
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
Otheranions	bismuth trifluoride; bismuth trichloride; bismuth triiodide
Othercations	nitrogen tribromide; phosphorus tribromide; arsenic tribromide; antimony tribromide; aluminium tribromide; iron(III) bromide
	Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa). Infobox references

Bismuth tribromideis aninorganic compoundofbismuthandbrominewith thechemical formulaBiBr₃.

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-temperaturepolymorphα-BiBr₃that is stable below 158 °C and a high-temperature polymorph β-BiBr₃that is stable above this temperature. Both polymorphs are monoclinic, but α-BiBr₃is inspace groupP2₁/a whereas β-BiBr₃is inC2/m. α-BiBr₃consists ofpyramidalmolecules whereas β-BiBr₃is polymeric and adopts theAlCl₃structure. BiBr₃is the onlygroup 15trihalide that can adopt both molecular and polymeric structures.^[3]

Reactivity

Bismuth bromide is highly water-soluble. It is aLewis acidand accepts bromide ions to form monomeric and oligomeric anionic complexes (bromobismuthates), e.g. [BiBr₆]³⁻,[Bi₂Br₁₀]⁴⁻,(BiBr⁻
₄)_nand (BiBr²⁻
₅)_n.^[4]

References

^^a ^b ^c ^d ^e ^f ^gGreenwood, 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 fromthe originalon 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 ^gGreenwood, 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 fromthe originalon 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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