Ozonide

Ozonide is the unstable, reactive polyatomic anion O−
3 analog of ozone or any of several classes of organic oxide compounds similarly formed by the reaction of ozone with an unsaturated compound.

Ozonide
Names
IUPAC name
Trioxidan-1-id-3-yl
Identifiers
3D model (JSmol)
ChemSpider
Properties
O−
3
Molar mass 47.999
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Ionic ozonides

Inorganic ozonides[1] are dark red ionic compounds containing the reactive O−
3 anion. The anion has the bent shape of the ozone molecule.

Inorganic ozonides are formed by burning potassium, rubidium, or caesium 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, NaO
3, which is prone to decomposition into NaOH and NaO
2, was previously thought to be impossible to obtain in pure form.[2] However, with the help of cryptands and methylamine, pure NaO
3 may be obtained as red crystals isostructural to NaNO
2.[3]

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

CsO3 + [(CH3)4N][O2] → CsO2 + [(CH3)4N][O3]

Covalent singly bonded structures

Phosphite ozonides, (RO)3PO3, are used in the production of singlet oxygen. They are made by ozonizing a phosphite ester in dichloromethane at low temperatures, and decompose to yield singlet oxygen and a phosphate ester:[4]

  1. (RO)3P + O3 → (RO)3PO3
  2. (RO)3PO3 → (RO)3PO + 1O2

Molozonides

Organic ozonides are called molozonides and are typically formed by the addition reaction between ozone and alkenes. They are more explosive cousins of the organic peroxides and as such are rarely isolated during the course of the ozonolysis reaction sequence. Molozonides are unstable and rapidly convert to the trioxolane ring structure with a five-membered C–O–O–C–O ring.[5][6] They usually appear in the form of foul-smelling oily liquids, and rapidly decompose in the presence of water to carbonyl compounds: aldehydes, ketones, peroxides.

Formation of an organic ozonide. The second arrow represents several steps as shown in ozonolysis.

See also

References
  1. F. A. Cotton and G. Wilkinson "Advanced Inorganic Chemistry", 5th edition (1988), p.462
  2. Korber, N.; Jansen, M. (1996). "Ionic Ozonides of Lithium and Sodium: Circumventive Synthesis by Cation Exchange in Liquid Ammonia and Complexation by Cryptands". Chemische Berichte. 129 (7): 773–777. doi:10.1002/cber.19961290707.
  3. Klein, W.; Armbruster, K.; Jansen, M. (1998). "Synthesis and crystal structure determination of sodium ozonide". Chemical Communications (6): 707–708. doi:10.1039/a708570b.
  4. Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 16: The group 16 elements". Inorganic Chemistry, 3rd Edition. Pearson. p. 496. ISBN 978-0-13-175553-6.
  5. Criegee, Rudolf. "Mechanism of Ozonolysis". Angewandte Chemie International Edition in English. 14 (11): 745–752. doi:10.1002/anie.197507451.
  6. https://www.organic-chemistry.org/namedreactions/ozonolysis-criegee-mechanism.shtm Ozonolysis mechanism on Organic Chemistry Portal site
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