Manganese(II,III) oxide Manganese(II,III) oxide Manganese(II,III) oxide is the chemical compound with formula MnO. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO.MnO. MnO is found in nature as the mineral hausmannite. MnO formed when any manganese oxide is heated in air above 1000 °C. Considerable research has centred on producing nanocrystalline MnO and various syntheses that involve oxidation of Mn or reduction of Mn. MnO has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide; the decomposition of NO, the reduction of
Manganese(IV) fluoride of the grains. The reaction can also be carried out starting from manganese powder in a fluidized bed. Other preparations of MnF include the fluorination of MnF with krypton difluoride, or with F in liquid hydrogen fluoride solution under ultraviolet light. Manganese tetrafluoride has also been prepared (but not isolated) in an acid–base reaction between antimony pentafluoride and KMnF as part of a chemical synthesis of elemental fluorine. Manganese tetrafluoride is in equilibrium with manganese(III) fluoride and elemental fluorine: Decomposition is favoured by increasing temperature, and disfavoured by the presence of fluorine gas, but the exact parameters of the equilibrium