Potassium peroxochromate, potassium tetraperoxochromate(V), or simply potassium perchromate, is an
inorganic chemical having the
chemical formula K
3 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 with
hydrogen peroxide 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