Sodium superoxide
Sodium superoxide is the inorganic compound with the formula NaO2. This yellow-orange solid is a salt of the superoxide anion. It is an intermediate in the oxidation of sodium by oxygen.Preparation
NaO2 is prepared by treating sodium peroxide with oxygen at high pressures:
It can also be prepared by careful oxygenation of a solution of sodium in ammonia:
It is also produced, along with sodium peroxide, when sodium is stored under inappropriate conditions.Properties
The product is paramagnetic, as expected for a salt of the anion. It hydrolyses readily to give a mixture of sodium hydroxide, oxygen and hydrogen peroxide. It crystallizes in the NaCl motif.
