Percobaltate Explained

Percobaltates are chemical compounds where the oxidation state of cobalt is +5. This is the highest established oxidation state of cobalt.^[1] The simplest of these are bi-metallic Group 1 oxides such as sodium percobaltate (Na₃CoO₄); which may be produced by the reaction of cobalt(II,III) oxide and sodium oxide, using oxygen as the oxidant:

4 Co₃O₄ + 18 Na₂O + 7 O₂ → 12 Na₃CoO₄

The potassium salt can be synthesized similarly; its magnetic moment has indicated the existence of cobalt(V).^{[2] [3]} No crystallographic analysis has been reported for either material. Percobaltates can be stabilized by use of oxides or fluorides.

A number of organometallic Co(V) complexes have also been reported.

See also

• Caesium hexafluorocobaltate(IV)

Notes and References

1. Riedel. Sebastian. Kaupp. Martin. The highest oxidation states of the transition metal elements. Coordination Chemistry Reviews. March 2009. 253. 5–6. 606–624. 10.1016/j.ccr.2008.07.014.
2. Brendel. Claus. Klemm. Wilhelm. Weitere Versuche zur Darstellung von Kaliumcobaltat (V). Zeitschrift für anorganische und allgemeine Chemie. January 1963. 320. 1–4. 59–63. 10.1002/zaac.19633200109. German.
3. Book: D. Nicholls. The Chemistry of Iron, Cobalt and Nickel: Comprehensive Inorganic Chemistry. 2 October 2013. Elsevier Science. 978-1-4831-4643-0. 1107–.