Ion, and compounds containing the ion
Chemical compound

Ozonide is the polyatomic anion O
3
. Cyclic organic compounds formed by the addition of ozone to an alkene are also called ozonides.

Ionic ozonides

Inorganic ozonides[1] are dark red salts. 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 labile 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[citation needed] 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 348 K (75 °C):

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

Alkaline earth metal ozonide compounds have also become known. For instance, magnesium ozonide complexes have been isolated in a low-temperature argon matrix.[5]

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:[6][7]

  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 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.[8][9] 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. ^ Cotton, F. A.; Wilkinson, G. (1988). Advanced Inorganic Chemistry (5th ed.). 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. ^ Jansen, Martin; Nuss, Hanne (August 2007). "Ionic Ozonides". Zeitschrift für anorganische und allgemeine Chemie. 633 (9): 1307–1315. doi:10.1002/zaac.200700023.
  5. ^ Wang, Guanjun & Gong, Yu & Zhang, Qingqing & Zhou, Mingfei. "Formation and Characterization of Magnesium Bisozonide and Carbonyl Complexes in Solid Argon". The journal of physical chemistry. A. 114 (2010). 10803-9. https://www.researchgate.net/publication/46392397_Formation_and_Characterization_of_Magnesium_Bisozonide_and_Carbonyl_Complexes_in_Solid_Argon
  6. ^ 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.
  7. ^ Wasserman HH, DeSimone RW, Chia KR, Banwell MG (2001). "Singlet Oxygen". Encyclopedia of Reagents for Organic Synthesis. e-EROS Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. doi:10.1002/047084289X.rs035. ISBN 978-0471936237.
  8. ^ Criegee, Rudolf (1975). "Mechanism of Ozonolysis". Angewandte Chemie International Edition in English. 14 (11): 745–752. doi:10.1002/anie.197507451.
  9. ^ Ozonolysis mechanism on Organic Chemistry Portal site

External links