Caesium bromide

Caesium bromide
IUPAC name	Caesium bromide
Other names	Cesium bromide, Caesium(I) bromide
Identifiers
InChI	InChI=1/BrH.Cs/h1H;/q;+1/p-1
CAS number	[7787-69-1]
EC number	232-130-0
PubChem	24592
Properties
Chemical formula	CsBr
Molar mass	212.81 g/mol
Appearance	White solid
Density	4.44 g/cm3, solid
Melting point	636 °C
Boiling point	1300 °C
Solubility in water	106.2 g/100 g (15 °C) 124.3 g/100 g (25 °C)
Structure
Crystal structure	CsCl
Coordination geometry	8–8
Hazards
EU index number	Not listed
Flash point	Non-flammable
Related compounds
Other anions	Caesium fluoride, Caesium chloride, Caesium iodide
Other cations	Sodium bromide, Potassium bromide Rubidium bromide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

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.

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.

Uses

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

See also

• Caesium fluoride
• Caesium chloride
• Caesium iodide

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