Cerium(III) bromide is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula CeBr₃. This white

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

solid is of interest as a component of

scintillation counter A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the Electron excitation, excitation effect of incident radiation on a Scintillation (physics), scintillating material, and detecting the resultant li ...

Preparation and basic properties

The compound has been known since at least 1899, when Muthman and Stützel reported its preparation from cerium sulfide and gaseous HBr. Aqueous solutions of CeBr₃ can be prepared from the reaction of Ce₂(CO₃)₃·H₂O with HBr. The product, CeBr₃·H₂O can be dehydrated by heating with NH₄Br followed by sublimation of residual NH₄Br. CeBr₃ can be distilled at reduced pressure (~ 0.1 Pa) in a quartz ampoule at 875-880 °C. Like the related salt CeCl₃, the bromide absorbs water on exposure to moist air. The compound melts congruently at 722 °C, and well ordered single crystals may be produced using standard crystal growth methods like Bridgman or Czochralski. CeBr₃ adopts the hexagonal, UCl₃-type crystal structure with the P6₃/m

space group In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that ...

. The cerium ions are 9-coordinate and adopt a tricapped trigonal prismatic geometry. The cerium–bromine bond lengths are 3.11 Å and 3.16 Å.

Applications

CeBr₃-doped lanthanum bromide single crystals are known to exhibit superior scintillation properties for applications in the security, medical imaging, and geophysics detectors. Undoped single crystals of CeBr₃ have shown promise as a γ-ray scintillation detector in nuclear non-proliferation testing, medical imaging,

environmental remediation Environmental remediation is the cleanup of hazardous substances dealing with the removal, treatment and containment of pollution or contaminants from Natural environment, environmental media such as soil, groundwater, sediment. Remediation may be ...

, and oil exploration.

Suppliers

Sigma-Aldrich

References

{{Lanthanide halides Cerium(III) compounds Bromides Lanthanide halides