Caesium azide or cesium azide is an inorganic compound of caesium and nitrogen. It is a salt of azide with the formula CsN3.
CsN3 adopts the same structure as KN3, RbN3, and TlN3, 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.[2] When heated to 151 °C, it transitions to a cubic structure.[3]
Caesium azide can be prepared from the neutralization reaction between hydrazoic acid and caesium hydroxide:[4]
CsOH + HN3 → CsN3 + H2O
Caesium carbonate can also be used as the base:
Cs2CO3 + HN3 → CsN3 + CO2 + H2O
Caesium sulfate reacts with barium azide to form insoluble barium sulfate and caesium azide:
Cs2SO4 + Ba(N3)2 → 2CsN3 + BaSO4↓
The thermal decomposition of CsN3 in vacuo can be used as a method of generating high purity caesium metal:[5]
2 CsN3 → 2 Cs + 3 N2