Ozonide

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Ozonide
Identifiers
PubChem 11966307
ChemSpider 10140300
Jmol-3D images Image 1
Properties
Molecular formula O3
Molar mass 47.999
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ozonide is an unstable, reactive polyatomic anion O3, derived from ozone, or an organic compound similar to organic peroxide formed by a reaction of ozone with an unsaturated compound.

Inorganic ozonides[edit]

Inorganic ozonides[1] 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, 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]

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

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.[4]

Organic ozonides[edit]

Organic ozonides are more explosive cousins of the organic peroxides formed by addition reactions of ozone and unsaturated compounds. They are intermediates in ozonolysis and have a 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. Due to their instability, they are rarely isolated during the course of the ozonolysis reaction sequence.

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

See also[edit]

References[edit]

  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.  edit
  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.  edit
  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, R. Angew. Chem. Int. Ed. Engl. 1975, 87, 745-752. (doi:10.1002/anie.197507451)
  6. ^ http://www.organic-chemistry.org/namedreactions/ozonolysis-criegee-mechanism.shtm Ozonolysis mechanism on Organic Chemistry Portal site

External links[edit]