Potassium tetraperoxochromate(V)

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Potassium tetraperoxochromate(V)
Potassium tetraperoxochrom.jpg
Identifiers
CAS number 12331-76-9 YesY
Properties
Molecular formula K
3
CrO
8
Molar mass 297.286
Appearance red brown
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Potassium peroxochromate, or potassium tetraperoxochromate(V), is an inorganic chemical having the chemical formula K3[Cr(O2)4]. A crystalline ionic solid with a brown color, it is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state.[1]

Preparation[edit]

Potassium peroxochromate is prepared by reacting hydrogen peroxide with potassium chromate at low temperatures:

2 CrO2−
4
+ 8 H
2
O
2
→ 2 [Cr(O
2
)
4
]2−
+ 8 H
2
O

The intermediate tetraperoxochromate(VI) is reduced by hydrogen peroxide, forming tetraperoxochromate(V):[2][3]

2 [Cr(O
2
)
4
]2−
+ 2 OH
+ H
2
O
2
→ 2 [Cr(O
2
)
4
]3−
+ 2 H
2
O
+ O
2

Thus, the overall reaction is:

2 CrO2−
4
+ 9 H
2
O
2
+ 2 OH
→ 2 [Cr(O
2
)
4
]3−
+ 10 H
2
O
+ O
2

The compound decomposes spontaneously at higher temperatures.

References[edit]

  1. ^ Sergienko, V. S. (2007). "Structural chemistry of peroxo compounds of group VI transition metals: I. Peroxo complexes of chromium". Crystallography Reports 52 (4): 639–646. Bibcode:2007CryRp..52..639S. doi:10.1134/S1063774507040116. 
  2. ^ Haxhillazi, Gentiana. "Preparation, Structure and Vibrational Spectroscopy of Tetraperoxo Complexes of CrV+, VV+, NbV+ and TaV+". 
  3. ^ Riesenfeld, E. H.; Wohlers, H.E.; Kutsch, W.A. (1905). "Höhere Oxydationsproducte des Chroms". Chemische Berichte der Deutschen Chemischen Gesellschaft 38: 1885–1898. doi:10.1002/cber.190503802113.