Mn2MnO4

Mn2MnO4 is not a standard or widely reported oxide of manganese. In established manganese–oxygen chemistry, common stoichiometries include MnO, MnO2, Mn2O3, Mn3O4, and Mn2O7. The notation Mn2MnO4 would correspond to a formula with two manganese atoms and four oxide ions, giving an average manganese oxidation state of +4. However, Mn2MnO4 is not recognized as a discrete, stable phase in conventional phase diagrams or mineral databases, and there is no well-defined crystal structure, synthesis route, or property data specific to a compound uniquely designated Mn2MnO4.

Several interpretations can be considered. It may reflect a misnotation or typographical error for Mn3O4 (manganese(II,III) oxide), MnO2 (manganese(IV) oxide), or for a mixed-oxide solid solution within the Mn–O system. In the manganese oxides, MnO2 occurs in several polymorphs and is widely used in catalysis and energy storage, whereas Mn3O4 has a spinel structure and contains Mn2+ and Mn3+. These well-characterized oxides provide reference points for understanding manganese-oxide chemistry and oxidation states.

Because Mn2MnO4 is not a standard or well-characterized compound, any use of this formula should be verified against primary databases or the scientific literature to determine whether it denotes a misprint, a transient intermediate, or a legitimate but obscure phase. Related topics for context include MnO2, Mn3O4, and broader manganese oxide chemistry.