Potassium dimanganate(III)

Potassium dimanganate(III), K₆Mn₂O₆, is a manganese(III) compound. Unlike lithium and sodium manganites, MMnO₂, which are best described as mixed oxides, potassium dimanganite contains discrete Mn₂O6−
6 anions in the solid state. It rapidly hydrolyzes in air.

K₆Mn₂O₆ is prepared as ruby-red crystals by the reaction of excess potassium oxide with manganese(II) oxide in a sealed nickel bomb at 610 °C for ten days. The Mn₂O6−
6 anion has an Al₂Cl₆-type structure.