Peroxide

Peroxides are a group of compounds with the structure R−O−O−R.[1] The O−O group in a peroxide is called the peroxide group or peroxo group. In contrast to oxide ions, the oxygen atoms in the peroxide ion have an oxidation state of −1.

Types of peroxides, from top to bottom: peroxide ion, organic peroxide, organic hydroperoxide, peracid. The peroxide group is marked in blue. R, R¹ and R² mark hydrocarbon moieties.

The most common peroxide is hydrogen peroxide (H₂O₂), colloquially known simply as "peroxide". It is marketed as a solution in water at various concentrations. Since hydrogen peroxide is nearly colorless, so are these solutions. It is mainly used as an oxidant and bleaching agent. However, hydrogen peroxide is also biochemically produced in the human body, largely as a result of a range of oxidase enzymes.[2] Concentrated solutions are potentially dangerous when in contact with organic compounds.

Structure and dimensions of H₂O₂.

Aside from hydrogen peroxide, some other major classes of peroxides are:

• Peroxy acids, the peroxy derivatives of many familiar acids, examples being peroxymonosulfuric acid and peracetic acid.
• Metal peroxides, examples being barium peroxide (BaO₂) and sodium peroxide (Na₂O₂).
• Organic peroxides, compounds with the linkage C−O−O−C or C−O−O−H. One example is tert-butylhydroperoxide.
• Main group peroxides, compounds with the linkage E−O−O−E (E = main group element), one example of which is potassium peroxydisulfate.