Caesium azide or cesium azide is an inorganic compound of caesium and nitrogen. It is a salt of azide with the formula .
adopts the same structure as , , and , crystallizing in a tetragonal distorted caesium chloride structure where each azide ion coordinates to eight metal cations, and each metal cation coordinates to eight terminal N centers. When heated to 151ðC, it transitions to a cubic structure.
Caesium azide can be prepared from the neutralization reaction between hydrazoic acid and caesium hydroxide:
Caesium carbonate can also be used as the base:
Caesium sulfate reacts with barium azide to form insoluble barium sulfate and caesium azide:
The thermal decomposition of in vacuo can be used as a method of generating high purity caesium metal: