Caesium bromide or cesium bromide is an ionic compound of caesium and bromine with the chemical formula CsBr. It is a white or transparent solid with melting point at 636 °C that readily dissolves in water. Its bulk crystals have the cubic CsCl structure, but the structure changes to the rocksalt type in nanometer-thin film grown on mica, LiF, KBr or NaCl substrates.
Synthesis Caesium bromide can be prepared via neutralization reactions: CsOH + HBr → CsBr + H2O Cs2(CO3) + 2 HBr → 2 CsBr + H2O + CO2 It can also be prepared by direct synthesis: 2 Cs + Br2 → 2 CsBr The direct synthesis is a vigorous reaction of caesium with bromine. Due to its high cost, it is not used for preparation.
Uses Caesium bromide is sometimes used in optics as a beamsplitter component in wide-band spectrophotometers.
References
Cited sources
Crystran Ltd experimental data July 2021
External links
MSDS at Oxford University Crystran Physical data , IR transmission spectrum Ultra-violet photoabsorption measurements in alkali iodide and caesium bromide evaporated films