Caesium azide

Caesium azide or cesium azide is an inorganic compound of caesium and nitrogen. It is a salt of azide with the formula CsN3.

Structure
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. When heated to 151°C, it transitions to a cubic structure.

Preparation and reactions
Caesium azide can be prepared from the neutralization reaction between hydrazoic acid and caesium hydroxide:

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:

2 CsN3 -> 2 Cs + 3 N2