Percobaltate

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.^{[citation needed]}

A number of organometallic Co(V) complexes have also been reported.^[1]

See also

• Caesium hexafluorocobaltate(IV)