Contents

Manganese(II,III) oxide

Manganese(II,III) oxide

Names
IUPAC name manganese(II) dimanganese(III) oxide
Other names Manganese tetroxide; Manganese oxide, Manganomanganic oxide, Trimanganese tetraoxide, Trimanganese tetroxide[1]
Identifiers
CAS Number	1317-35-7 Y
3D model (JSmol)	Interactive image
ECHA InfoCard	100.013.879
PubChem CID	14825
RTECS number	OP0895000
UNII	70N6PQL9JS Y
CompTox Dashboard (EPA)	DTXSID9051660
InChI InChI=1S/3Mn.4O Key: GVNFAUMGUISVJW-UHFFFAOYSA-N
SMILES [Mn]=O.O=[Mn]O[Mn]=O
Properties
Chemical formula	Mn3O4 MnO·Mn2O3
Molar mass	228.812 g/mol
Appearance	brownish-black powder[1]
Density	4.86 g/cm3
Melting point	1,567 °C (2,853 °F; 1,840 K)
Boiling point	2,847 °C (5,157 °F; 3,120 K)
Solubility in water	insoluble
Solubility	soluble in HCl
Magnetic susceptibility (χ)	+12,400·10−6cm3/mol
Structure
Crystal structure	Spinel (tetragonal), tI28
Space group	I41/amd, No. 141
Hazards
NIOSH (US health exposure limits):
PEL (Permissible)	C 5 mg/m3[1]
REL (Recommended)	None established[1]
IDLH (Immediate danger)	N.D.[1]
Thermochemistry
Std molar entropy (S⦵298)	149 J·mol−1·K−1[2]
Std enthalpy of formation (ΔfH⦵298)	−1387 kJ·mol−1[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Chemical compound

Manganese(II,III) oxide is the chemical compound with formula Mn₃O₄. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO·Mn₂O₃. Mn₃O₄ is found in nature as the mineral hausmannite.

Preparation[edit]

Mn₃O₄ formed when any manganese oxide is heated in air above 1000 °C.^[3] Considerable research has centred on producing nanocrystalline Mn₃O₄ and various syntheses that involve oxidation of Mn^II or reduction of Mn^VI.^[4][5][6]

Reactions[edit]

Mn₃O₄ has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide;^[7][8] the decomposition of NO,^[9] the reduction of nitrobenzene^[10] and the catalytic combustion of organic compounds.^[11]

Structure[edit]

Mn₃O₄ has the spinel structure, where the oxide ions are cubic close packed and the Mn^II occupy tetrahedral sites and the Mn^III octahedral sites.^[3] The structure is distorted due to the Jahn–Teller effect.^[3] At room temperature Mn₃O₄isparamagnetic, below 41-43 K, it is ferrimagnetic^[12] although this has been reported as reducing in nanocrystalline samples to around 39 K.^[13]

Uses[edit]

Mn₃O₄ is sometimes used as a starting material in the production of soft ferrites e.g. manganese zinc ferrite,^[14] and lithium manganese oxide, used in lithium batteries.^[15]

Manganese tetroxide can also be used as a weighting agent while drilling reservoir sections in oil and gas wells.^{[citation needed]}

References[edit]