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 Mn2O$6− 6$ 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 Mn2O$6− 6$ anion has an Al2Cl6-type structure.