in North America), is an inorganic compound
usually encountered as a hygroscopic white solid. It is more soluble and more readily dissociated
than sodium fluoride
or potassium fluoride
. It is available in anhydrous form, and if water has been absorbed it is easy to dry by heating at 100 °C
for two hours in vacuo
. Like all soluble fluorides, it is mildly basic
. A notable fact about this compound is that it is the most ionic compound. Caesium has the lowest electronegativity
and fluorine has the highest electronegativity.
Synthesis and properties
Caesium fluoride is prepared by the action of hydrofluoric acid
on caesium hydroxide
or caesium carbonate
, followed by removal of water.
Caesium fluoride reacts usually as a source of fluoride ion, F<sup>-</sup>. It therefore undergoes all of the usual reactions associated with soluble fluorides, for example:Greenwood, N.N.; Earnshaw, A. Chemistry of the Elements
, Pergamon Press, Oxford, UK, 1984.
- 2 CsF + CaCl<sub>2</sub> → 2 CsCl + CaF<sub>2</sub>
Caesium fluoride has the halite structure, which means that the Cs<sup>+</sup> and F<sup>−</sup> pack in a cubic closest packed
array as do Na<sup>+</sup> and Cl<sup>−</sup> in sodium chloride. Caesium cations are larger... Read More