Caesium bromide

Caesium bromide
Names
	IUPAC name Cesium bromide
	Other names Cesium bromide,; Caesium(I) bromide
Identifiers
CAS Number	7787-69-1 ;
3D model (JSmol)	Interactive image;
ChemSpider	22994 ;
ECHA InfoCard	100.029.209
EC Number	232-130-0;
PubChem CID	24592;
RTECS number	FK9275000;
UNII	06M25EDM3F;
CompTox Dashboard (EPA)	DTXSID8064854 ;
	InChI InChI=1S/BrH.Cs/h1H;/q;+1/p-1 Key: LYQFWZFBNBDLEO-UHFFFAOYSA-M ; InChI=1/BrH.Cs/h1H;/q;+1/p-1 Key: LYQFWZFBNBDLEO-REWHXWOFAA;
	SMILES [Cs+].[Br-];
Properties
Chemical formula	CsBr
Molar mass	212.809 g/mol
Appearance	White solid
Density	4.43 g/cm3
Melting point	636 °C (1,177 °F; 909 K)
Boiling point	1,300 °C (2,370 °F; 1,570 K)
Solubility in water	1230 g/L (25 °C) Disputed. 420 g/L (11 °C) See References; 560 /L (15°C); 1020 g/L (28.5 °C); 1180 g/L (31 °C); 1240 g/L (32.5 °C); 1380 g/L (35 °C)
Magnetic susceptibility (χ)	-67.2·10−6 cm3/mol
Refractive index (nD)	1.8047 (0.3 μm); 1.6974 (0.59 μm); 1.6861 (0.75 μm); 1.6784 (1 μm); 1.6678 (5 μm); 1.6439 (20 μm)
Structure
Crystal structure	CsCl, cP2
Space group	Pm3m, No. 221
Lattice constant	a = 0.4291 nm
Lattice volume (V)	0.0790 nm3
Formula units (Z)	1
Coordination geometry	Cubic (Cs+); Cubic (Br−)
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 0 0
Flash point	Non-flammable
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	1400 mg/kg (oral, rat)
Related compounds
Other anions	Caesium fluoride; Caesium chloride; Caesium iodide; Caesium astatide
Other cations	Sodium bromide; Potassium bromide; Rubidium bromide; Francium bromide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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.^[6]

Synthesis

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 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

^ ^a ^b ^c ^d ^e Haynes, p. 4.57
^ Haynes, p. 4.132
^ Haynes, p. 10.240
^ Vallin, J.; Beckman, O.; Salama, K. (1964). "Elastic Constants of CsBr and CsI from 4.2K to Room Temperature". Journal of Applied Physics. 35 (4): 1222. Bibcode:1964JAP....35.1222V. doi:10.1063/1.1713597.
^ Caesium bromide. nlm.nih.gov
^ Schulz, L. G. (1951). "Polymorphism of cesium and thallium halides". Acta Crystallographica. 4 (6): 487–489. Bibcode:1951AcCry...4..487S. doi:10.1107/S0365110X51001641.