Caesium bromide

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Caesium bromide
IUPAC name	Caesium bromide
Other names	Cesium bromide, Caesium (I) bromide, Tricesium tribromide
Identifiers
CAS number	[7787-69-1]
PubChem	24592
EINECS number	232-130-0
SMILES	CsBr
InChI	1/BrH.Cs/h1H;/q;+1/p-1
Properties
Molecular formula	CsBr
Molar mass	212.809 g/mol
Appearance	White solid
Density	4.44 g/cm3, solid
Melting point	636 °C
Boiling point	1300 °C
Solubility in water	1062 g/l at 15 °C 1243 g/l at 25 °C
Structure
Crystal structure	Cubic (BCC)
Coordination geometry	8
Hazards
R-phrases	R36/37/38
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Caesium bromide, (CsBr), is an ionic compound of caesium and bromine. It has body-centered cubic crystallic structure of caesium chloride type with space group Pm3m and lattice constant a = 0.42953 nm. Distance between Cs and Br atoms is 0.30372 nm.

Contents 1 Synthesis 2 Uses 3 See also 4 External links

[edit] Synthesis

It can be prepared via following reactions:

• Neutralisation:

CsOH (aq) + HBr (aq) → CsBr (aq) + H₂O (l)

Cs₂(CO₃) (aq) + 2 HBr (aq) → 2 CsBr (aq) + H₂O (l) + CO₂ (g)

• Direct synthesis:

2 Cs (s) + Br₂ (g) → 2 CsBr (s)

The direct synthesis is vigorous reaction as reaction of caesium with other halogens. Due to its expensiveness, it is not used for preparation.

[edit] Uses

Caesium bromide is sometimes used in optics as a beamsplitter component in wide-band spectrophotometers.

[edit] See also

• Caesium fluoride
• Caesium chloride
• Caesium iodide

[edit] External links

• MSDS at Oxford University
• Physical data, PDF version
• Caesium bromide at webelements.com
• Relaxed Excited States Origin and Structure in Lead-Doped Caesium Bromide
• IR transmission spectrum
• Ultra-violet photoabsorption measurements in alkali iodide and caesium bromide evaporated films