Chromium(VI) oxide peroxide
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IUPAC name
Chromium(VI) oxide diperoxide
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Other names
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3D model (
JSmol ) |
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PubChem CID
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Properties | |
CrO(O2)2 | |
Molar mass | 131.991 g·mol−1 |
Appearance | Dark blue |
soluble (decomposes without stabilisers) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Chromium(VI) oxide peroxide or chromium oxide peroxide or more accurately chromium(VI) oxide diperoxide is an inorganic compound with the chemical formula CrO5 or more accurately CrO(O2)2. It is an unstable dark blue compound. This compound contains one oxo ligand and two peroxo ligands, making a total of five oxygen atoms per chromium atom.
Preparation and properties
Chromium(VI) oxide peroxide is formed by the addition of acidified
- CrO2−4 + 2 H2O2 + 2 H+ → CrO(O2)2 + 3 H2O
With this method, the chromium(VI) oxide peroxide will decompose after a few seconds, turning green as chromium(III) compounds are formed.[1]
- 2 CrO(O2)2 + 7 H2O2 + 6 H+ → 2 Cr3+ + 10 H2O + 7 O2
To avoid this decomposition, it is possible to stabilize chromium(VI) oxide peroxide in water-immiscible organic solvents such as
CrO(O2)2 is unstable and decomposes on standing to form CrO3. It is incompatible with ketones and primary alcohols, as it oxidizes them to aldehydes and carboxylic acids while being itself reduced to Cr3+. Therefore, CrO(O2)2 is a good oxidizing agent, even better than chromates and dichromates due to the presence of two reactive peroxo ligands, but due to its low stability it is not used in organic syntheses.[citation needed]
Derivatives
The
The structure of the pyridine complex has been determined crystallographically.[3]
Gallery
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An aqueous solution of chromium peroxide
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A very dilute solution of chromium peroxide
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chromium(VI) oxide peroxide stabilized in ether phase (above) and chromium(III) aqueous solution (below).
See also
- Tetraperoxochromate- an similarly-synthesized analogous chromium(V) peroxide complex
References
- ISBN 3-11-007511-3."
- .
- S2CID 4187294.
External links
- Experimental details and photo (in German)
- Losing fingers to chemistry on YouTube (8 November 2012). Professor Martyn Poliakoff of the University of Nottingham demonstrates the synthesis on Periodic Videos.