Caesium chloride
| Caesium chloride | | |
| General |
|---|
| Other names | Cesium chloride |
| Molecular formula | CsCl |
| Molar mass | 168.36 g/mol |
| Appearance | white solid |
| CAS number | [7647-17-8] |
| EINECS number | 231-600-2 |
| Properties |
|---|
| Density and phase | 3.99 g/cm3, solid |
| Solubility in water | 162 g/100 ml (1 °C) |
In methanol
In ethanol
In acetone | 33.7 g/100 ml
Very soluble
Insoluble |
| Melting point | 645°C |
| Boiling point | 1295°C |
| Structure |
|---|
| Coordination geometry | simple cubic |
| Crystal structure | see text |
| Thermodynamic data |
!>| Supplementary data page|
| Structure & properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour
Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds |
|---|
| Other s | Caesium fluoride
Caesium bromide
Caesium iodide |
| Other s | Potassium chloride
Rubidium chloride |
Except where noted otherwise, data are given for
materials in their standard state (at 25°C, 100 kPa)
Infobox disclaimer and references |
|
Caesium chloride is an ionic compound best known as a
structural type.
Caesium chloride can be prepared by the reaction of
caesium hydroxide or
caesium carbonate with
hydrochloric acid: the resulting salt is purified by
recrystallization.
Caesium metal reacts violently with
chlorine gas to give caesium chloride, although the expense of metallic caesium means that this is not the usual route of preparation.
|
Caesium chloride crystal structure |
The caesium chloride structure is composed of interlocking simple cubic lattices of anions and cations. It is the case that in a cubic 1:1 solid where one atom type is much larger than the other that the cesium chloride type lattice is obtained, it can be thought of as a combination of
footballs and
golf balls packed in a cubic manner with the
golf balls in the gaps between the footballs. If the two atom types are similar in size (imagine
hockey balls packed with
tennis balls) then in the cubic lattice the structure will be like that of
sodium chloride.
Caesium chloride is used in the preparation of electrically conducting
glasses.
Radioisotopes of caesium chloride are used in
nuclear medicine, including treatment of
cancer. In the production of
radioactive sources it is normal to choose a chemical form of the radioisotope which will not be dispersed with ease in the environment as a result of an accident where the source is smashed open. For instance
radiothermal generators (RTGs) often use
strontium titanate because it is insoluble in water. But for
teletherapy sources the radioactive density (Ci in a given volume) needs to be very high, as a result it is not possible with any of the insoluble caesium compounds to create the source. As a result it is normal to use a thimble shaped can of
radioactive caesium chloride to provide the active source in a teletherapy type radiotherapy unit. In Brazil such a source was stolen by
scrap metal workers from a disused
radiotherapy clinic, and serious injurys and deaths occurred as a result of external gamma exposure and internal exposure (the source was smashed open, releasing the water soluble cesium chloride). See the
Goiânia accident for further details.
# Tver'yanovich, Y. S.
et al. (1998).
Glass Phys. Chem.,
24, 446.
