Cesium Chloride

Title: Cesium Chloride
CAS Registry Number: 7647-17-8
Molecular Formula: ClCs
Molecular Weight: 168.36
Percent Composition: Cl 21.06%, Cs 78.94%
Line Formula: CsCl
Literature References: Prepn from carnallite and from pollucite: Donges in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 951, 955. Toxicity study: Cochran et al., Arch. Ind. Hyg. 1, 637 (1950).
Properties: Deliquesc cubic crystals. d 3.99. mp 646°. bp 1303°. Very sol in water; sol in alc. Keep well closed. LD50 i.p. in rats: 1.5 g/kg (Cochran).
Melting point: mp 646°
Boiling point: bp 1303°
Density: d 3.99
Toxicity data: LD50 i.p. in rats: 1.5 g/kg (Cochran)
Derivative Type: 131CsCl
Trademarks: Cescan-131 (Abbott)
Use: In the final evacuation of radio and television vacuum tubes; in x-ray fluorescent screens; as radiographic contrast medium; in manuf of cesium.
Cesium Fluoride Cesium Hydroxide Cesium Iodide Cesium Nitrate Cesium Sulfate

Caesium chloride
Caesium chloride
Caesium chloride
Identifiers
CAS number 7647-17-8 YesY
ChemSpider 22713 YesY
UNII GNR9HML8BA YesY
EC number 231-600-2
Jmol-3D images Image 1
Properties
Molecular formula CsCl
Molar mass 168.36 g/mol
Appearance white solid
hygroscopic
Density 3.99 g/cm3
Melting point 645 °C, 918.15 K
Boiling point 1297 °C, 1570.15 K (vaporizes)
Solubility in water 1865 g/L[2]
Solubility soluble in ethanol[3]
Band gap 8.35 eV (80 K)[1]
Refractive index (nD) 1.64[4]
Structure
Crystal structure Caesium chloride (see text), Pm3m, space group No. 221, Pearson symbol cP2
Coordination
geometry
simple cubic (interpenetrating)
Related compounds
Other anions Caesium fluoride
Caesium bromide
Caesium iodide
Caesium astatide
Other cations Lithium chloride
Sodium chloride
Potassium chloride
Rubidium chloride
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Caesium chloride or cesium chloride, is the inorganic compound with the formula CsCl. This colorless solid is an important source of caesium ions in a variety of applications. Its crystal structure forms a major structural type where each caesium ion is coordinated by 8 chlorine ions. Caesium chloride crystals are thermally stable, but easily dissolve in water and concentrated hydrochloric acid, and therefore gradually disintegrate in the ambient conditions due to moisture. Caesium chloride occurs naturally in mineral waters and as an impurity in carnallite (up to 0.002%), sylvite and kainite. Less than 20 tonnes of CsCl is produced annually worldwide, mostly from a caesium-bearing mineral pollucite.[5]

Caesium chloride is widely used in isopycnic centrifugation for separating various types of DNA. It is a reagent in analytical chemistry, where it is used to identify ions by the color and morphology of the precipitate. When enriched in radioisotopes, such as 137CsCl or 131CsCl, caesium chloride is used in nuclear medicine applications such as treatment of cancer and diagnosis of myocardial infarction. Another form of cancer treatment was studied using conventional non-radioactive CsCl. Whereas conventional caesium chloride has a rather low toxicity to humans and animals, the radioactive form easily contaminates the environment due to the high solubility of CsCl in water. Spread of 137CsCl powder from a 93-gram container in 1987 in Goiânia, Brazil, resulted in one of the worst-ever radiation spill accidents killing four and directly affecting more than 100,000 people.