Superoxide
Lewis structure of superoxide. The six outer-shell electrons of each oxygen atom are shown in black; one electron pair is shared (middle); the unpaired electron is shown in the upper-left; and the additional electron conferring a negative charge is shown in red. | |
| Names | |
|---|---|
| IUPAC name
Superoxide | |
| Systematic IUPAC name
Dioxidan-2-idylide | |
| Other names
Hyperoxide, Dioxide(1−) | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| 487 | |
| KEGG | |
PubChem CID |
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| UNII | |
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| Properties | |
| O−2 | |
| Molar mass | 31.998 g·mol−1 |
| Conjugate acid | Hydroperoxyl |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula O−2. The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature. Molecular oxygen (dioxygen) is a diradical containing two unpaired electrons, and superoxide results from the addition of an electron which fills one of the two degenerate molecular orbitals, leaving a charged ionic species with a single unpaired electron and a net negative charge of −1. Both dioxygen and the superoxide anion are free radicals that exhibit paramagnetism. Superoxide was historically also known as "hyperoxide".