Cesium bromide

Cesium bromide is a colorless crystal with the formula CsBr. It is a moderately water soluble crystalline Cesium source that decomposes to Cesium oxide on heating. Most metal bromine compounds are water-soluble and are used in water treatment, chemical analysis, and ultra-high purity for certain crystal growth applications.

Cesium bromide is a colourless crystals. It has been used in protein crystallization for anamolous scattering.

In x-ray fluorescent screens, spectrometer prisms, absorption-cell windows.

Cesium bromide (CsBr) crystals are used in scintillation counters to detect radiation. The compound is also used to coat the inside of fluorescent screens.

Caesium bromide can be prepared via following reactions:
Neutralization:
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 a vigorous reaction of caesium with other halogens. Due to its high cost, it is not used for preparation.

Single crystals Cesium bromide can be synthesized by the Kyropoulus method or the Stockbarger method. One can polish the crystal using pure alcohol.

Moderately toxic by intraperitoneal route. See also CESIUM and BROMIDES. When heated to decomposition it emits toxic fumes of Br-.

It is very soluble in H2O, soluble in EtOH but insoluble in Me2CO. Dissolve it in the minimum volume of H2O, filter and precipitate it by adding Me2CO. Filter off the solid and dry it at 100o. Also recrystallise it from water (0.8mL/g) by partial evaporation in a desiccator.

The space lattice of CsBr(Cesium bromide) belongs to the cubic system, and its cesium chloride structure has a lattice constant of a=0.429 nm.

Cesium bromide (CsBr) is Tetraauricupride structured and crystallizes in the cubic Pm̅3m space group. Cs¹⁺ is bonded in a body-centred cubic geometry to eight equivalent Br¹⁻ atoms. All Cs-Br bond lengths are 3.75 Å. Br¹⁻ is bonded in a body-centered cubic geometry to eight equivalent Cs¹⁺ atoms.

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