Sodium superoxide
Sodium superoxide is the inorganic compound with the formula NaO2.[1] 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:[2]
- Na2O2 + O2 → 2 NaO2
It can also be prepared by careful oxygenation of a solution of sodium in cryogenic liquid ammonia:
- Na(in NH3) + O2 → NaO2
Although the existence of a sodium oxide higher than peroxide was speculated since 19th century, it was not until 1948 when American chemists were able to definitely synthesize it by the latter method.[3]
It is also produced, along with sodium peroxide, when sodium is stored under inappropriate conditions (e.g. in dirty or partially halogenated solvents)Script error: No such module "Unsubst"..
Properties
The product is paramagnetic, as expected for a salt of the Template:Chem/link anion. It hydrolyses readily to give a mixture of sodium hydroxide, oxygen and hydrogen peroxide.[4] It crystallizes in the NaCl motif.
References
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- ↑ Stephen E. Stephanou, Edgar J. Seyb Jr., Jacob Kleinberg "Sodium Superoxide" Inorganic Syntheses 1953; Vol. 4, 82-85.
- ↑ Script error: No such module "Citation/CS1".
- ↑ Sasol Encyclopaedia of Science and Technology , G.C. Gerrans, P. Hartmann-Petersen , p.243 "sodium oxides" , google books link