Potassium peroxochromate, potassium tetraperoxochromate(V), or simply potassium perchromate, is an
inorganic
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemis ...
chemical having the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
K
3 2)4">r(O2)4 It is a red-brown paramagnetic solid. It is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state and one of the rare examples of a complex stabilized only by peroxide ligands. This compound is used as a source of
singlet oxygen
Singlet oxygen, systematically named dioxygen(singlet) and dioxidene, is a gaseous inorganic chemical with the formula O=O (also written as or ), which is in a quantum state where all electrons are spin paired. It is kinetically unstable at ambie ...
.
Preparation
Potassium peroxochromate is prepared by treating
potassium chromate
Potassium chromate is the inorganic compound with the formula K2 CrO4. This yellow solid is the potassium salt of the chromate anion. It is a common laboratory chemical, whereas sodium chromate is important industrially.
Structure
Two crysta ...
with
hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3% ...
at 0 ºC:
: 2 + 8 → 2 + 8
The intermediate tetraperoxochromate(VI) is reduced by hydrogen peroxide, forming tetraperoxochromate(V):
[
]
: 2 + 2 + → 2 + 2 +
Thus, the overall reaction is:
:2 + 9 + 2 → 2 + 10 +
The compound decomposes spontaneously at higher temperatures.
References
{{Chromium compounds
Potassium compounds
Chromium–oxygen compounds
Oxidizing agents
Peroxides
Chromium(V) compounds