Ozonide - Inorganic Ozonides

Inorganic ozonides are dark red ionic compounds containing the reactive O₃− anion. The anion has the V shape of the ozone molecule.

Inorganic ozonides are formed by burning potassium or heavier alkali metals in ozone, or by treating the alkali metal hydroxide with ozone; if potassium is left undisturbed in air for years it accumulates a covering of superoxide and ozonide. They are very sensitive explosives that have to be handled at low temperatures in an atmosphere consisting of an inert gas. Lithium and sodium ozonide are extremely unstable and must be prepared by low-temperature ion exchange starting from CsO₃. Sodium ozonide, NaO₃, which is prone to decomposition into NaOH and NaO₂, was previously thought to be impossible to obtain in pure form. However, with the help of cryptands and methylamine, pure NaO₃ may be obtained as red crystals isostructural to NaNO₂.

Inorganic ozonides are being investigated as promising sources of oxygen in chemical oxygen generators, as tetramethylammonium ozonide, which can be made by a metathesis reaction with caesium ozonide in liquid ammonia, is stable up to 348K:

CsO₃ + → CsO₂ +

Phosphite ozonides, (RO)₃PO₃, are used in the production of singlet oxygen, which is made by ozonizing a phosphite ester in dichloromethane at low temperatures.