Manganese(II,III) oxide a weighting agent while drilling reservoir sections in oil and gas wells. 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
Methylcyclopentadienyl manganese tricarbonyl ferrocene, which has also been used as an additive to gasoline. Although of no practical value, the related compound cyclopentadienyl manganese tricarbonyl (CH)Mn(CO) is also well studied. Up to two of the CO ligands in MMT can be replaced with thiocarbonyl groups, as illustrated by the compounds (CHCH)Mn(CS)CO and (CHCH)Mn(CS)(CO). The human and environmental health impacts that may result from the use of MMT will be a function of exposure to either: (1) MMT in its original, unchanged, chemical form and/or (2) manganese combustion products emitted from vehicles operating on gasoline containing MMT as an octane improver. The general public