Potassium dimanganate(III)

{{chembox

| verifiedrevid = 370514132

| IUPACName = potassium di-µ-oxidotetraoxidodimanganate(6−)

|Section1 = {{Chembox Identifiers

| PubChem = 139046909

| SMILES = [K+].[K+].[K+].O=[Mn-3]0(=O)O[Mn-3](O0)(=O)=O.[K+].[K+].[K+]

| StdInChI=1S/6K.2Mn.6O/q6*+1;2*+3;6*-2

| StdInChIKey = UXOXVZBXGUUTNN-UHFFFAOYSA-N

}}

|Section2 = {{Chembox Properties

| Properties_ref = {{citation | title = Das erste Oxomanganat(III) mit Inselstruktur: K₆[Mn₂O₆] | journal = Naturwissenschaften | volume = 63 | issue = 7 | year = 1976 | doi = 10.1007/BF00597313 | page = 339 | first1 = G. | last1 = Brachtel | first2 = R. | last2 = Hoppe| bibcode = 1976NW.....63..339B | s2cid = 45344152 }}.

| Formula = K₆Mn₂O₆

| MolarMass = 440.46 g mol⁻¹

| Appearance = Ruby-red crystals

}}

|Section3={{Chembox Structure

| Structure_ref =

| SpaceGroup = P2₁/b (No. 14)

| Coordination = Distorted tetrahedral (Mn³⁺)

| LattConst_a = 889(5) pm

| LattConst_b = 677(5) pm

| LattConst_c = 1137(9) pm

| LattConst_gamma = 132.1

}}

|Section8={{Chembox Related

| OtherAnions = Potassium hypomanganate
Potassium manganate
Potassium permanganate

}}

}}

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{{su|b=6|p=6−}} anions in the solid state.{{Cotton&Wilkinson4th|page=741}}. 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{{su|b=6|p=6−}} anion has an Al₂Cl₆-type structure.