Peroxycarbonate Explained

In chemistry, peroxycarbonate (sometimes peroxocarbonate, IUPAC name: oxocarbonate or oxidocarbonate) or percarbonate is a divalent anion with formula . It is an oxocarbon anion that consists solely of carbon and oxygen. It would be the anion of a hypothetical peroxycarbonic acid HO–CO–O–OH (sometimes peroxocarbonic acid).^{[1] [2]} or the real hydroperoxyformic acid, HO-O-CO-OH (a.k.a. percarbonic acid, carbonoperoxoic acid, hydroxycarbonic acid).

The peroxycarbonate anion is formed, together with peroxydicarbonate, at the negative electrode during electrolysis of molten lithium carbonate.^[3] Lithium peroxycarbonate can be produced also by combining carbon dioxide with lithium hydroxide in concentrated hydrogen peroxide H₂O₂ at −10 °C.^[4]

Electrolysis of a solution of lithium carbonate at -30° to -40 °C yields a solution of the Lithium percarbonate, which can liberate iodine from potassium iodide instantaneously. The crystalline salt has not been isolated.

The peroxycarbonate anion has been proposed as an intermediate to explain the catalytic effect of CO₂ on the oxidation of organic compounds by O₂.

The potassium and rubidium salts of the monovalent hydrogenperoxycarbonate anion (aka. hydroxycarbonate, biperoxycarbonate) have also been obtained.^{[5] [6] [7] [8]}

See also

• Sodium percarbonate, actually a perhydrate of sodium carbonate.
• Sodium peroxycarbonate
• Orthocarbonate anion
• Dipropyl peroxydicarbonate

Notes and References

1. Die Existenz echter Percarbonate und ihre Unterscheidung von Carbonaten mit Krystall-Wasserstoffsuperoxyd . 1909 . Riesenfeld . E. H. . Reinhold . B. . Berichte der Deutschen Chemischen Gesellschaft . 42 . 4 . 4377–4383 . 10.1002/cber.19090420428 .
2. Isomere Percarbonate . 1911 . Riesenfeld . E. H. . Mau . W. . Berichte der Deutschen Chemischen Gesellschaft . 44 . 3 . 3595–3605 . 10.1002/cber.191104403244 .
3. 10.1021/jp035749l . First Spectroscopic Observation of Peroxocarbonate/ Peroxodicarbonate in Molten Carbonate . 2004 . Chen . Li-Jiang . Lin . Chang-Jian . Zuo . Juan . Song . Ling-Chun . Huang . Chao-Ming . The Journal of Physical Chemistry B . 108 . 23 . 7553–7556 .
4. 10.1007/BF00922073. Synthesis and some properties of lithium peroxocarbonate. 1975. Firsova. T. P.. Kvlividze. V. I.. Molodkina. A. N.. Morozova. T. G.. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science. 24. 6. 1318–1319.
5. Mimoza Gjikaj (2001), "Darstellung und strukturelle Charakterisierung neuer Alkali- bzw. Erdalkalimetallperoxide, -hydrogenperoxide, -peroxocarbonate und -peroxohydrate" . Doctoral Thesis, University of Köln. 115 pages.
6. Adam. Arnold. Mehta. Mathias. 1998. KH(O₂)CO₂·H₂O₂—An Oxygen-Rich Salt of Monoperoxocarbonic Acid. Angewandte Chemie International Edition. en. 37. 10. 1387–1388. 10.1002/(SICI)1521-3773(19980605)37:10<1387::AID-ANIE1387>3.0.CO;2-3 . 29710903. 1521-3773.
7. M. Mehta and A. Adam (1998), Z. Kristallogr., Suppl. Issue 15 p. 53. Cited by Gjikaj.
8. M. Mehta and A. Adam (1998), Z. Kristallogr., Suppl. Issue 15 p. 46. Cited by Gjikaj.