Manganese(III) oxide Manganese(III) oxide Manganese(III) oxide is a chemical compound with the formula MnO. Heating MnO in air at below 800 °C produces α-MnO (higher temperatures produce MnO). γ-MnO can be produced by oxidation followed by dehydration of manganese(II) hydroxide. Many preparations of nano-crystalline MnO have been reported, for example syntheses involving oxidation of Mn salts or reduction of MnO. Manganese (III) oxide is formed by the redox reaction in an alkaline cell: Manganese (III) oxide MnO must not be confused with MnOOH manganese (III) oxyhydroxide. Contrary to MnO, MnOOH is a compound that decomposes at about 300 °C to form MnO.
Manganese dioxide Manganese dioxide Manganese(IV) oxide is the inorganic compound with the formula . This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for is for dry-cell batteries, such as the alkaline battery and the zinc-carbon battery. is also used as a pigment and as a precursor to other manganese compounds, such as . It is used as a reagent in organic synthesis, for example, for the oxidation of allylic alcohols. in the α polymorph can incorporate a variety of atoms (as well as