Manganese(III) oxide: Difference between revisions

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| verifiedrevid = 413856748

| ImageFile = Tl2O3structure.jpg

| ImageSize =

| IUPACName =

| OtherNames = dimanganese trioxide, manganese sesquioxide, manganic oxide

| Section1 = {{Chembox Identifiers

| CASNo_Ref = {{cascite}}

| PubChem = 14827

| SMILES = }}

| Section2 = {{Chembox Properties

| MeltingPt = 940 °C (decomp)

| Solubility = insoluble

| SolubleOther = insoluble in [[alcohol]], [[acetone]] <br> soluble in [[acid]]

| Section3 = {{Chembox Structure

| CrystalStruct = [[Cubic crystal system|Cubic]], [[Pearson symbol|cI80]]<ref>{{cite journal| journal = Physica C| year = 1993|volume = 215|page = 205| title = Further evidence for Tl3+ in Tl-based superconductors from improved bond strength parameters involving new structural data of cubic Tl2O3| author = Otto H.H., Baltrasch R., Brandt H.J.| doi=10.1016/0921-4534(93)90382-Z}}</ref>

| SpaceGroup = Ia-3, No. 206

}}

| Section7 = {{Chembox Hazards

| Autoignition = }}

| Section4 = {{Chembox Related

| OtherCpds = [[manganese(II) oxide]], [[manganese dioxide]] }}

'''Manganese(III) oxide''' is the chemical compound of formula Mn₂O₃.

Heating MnO₂ in air at below 800°C α-Mn₂O₃ is produced (higher temperatures produce Mn₃O₄).<ref name = "Greenwood">{{Greenwood&Earnshaw}}</ref> γ-Mn₂O₃ can be produced by oxidation followed by dehydration of manganese(II) hydroxide.<ref name = "Greenwood"/> Many preparations of nano-crystalline Mn₂O₃ have been reported, for example syntheses involving oxidation of Mn^II salts or reduction of MnO₂.<ref>{{cite journal|title=Preparation of α-Mn₂O₃ and MnO from thermal decomposition of MnCO₃ and control of morphology|author=Shuijin Lei, Kaibin Tang, Zhen Fang, Qiangchun Liu, Huagui Zheng|journal=Materials Letters|volume=60|year=2006|page=53|doi=10.1016/j.matlet.2005.07.0}}</ref><ref>{{cite journal|title=A facile preparation of single-crystalline α-Mn₂O₃ nanorods by ammonia-hydrothermal treatment of MnO₂|author=Zhong-Yong Yuan, Tie-Zhen Ren, Gaohui Du, Bao-Lian Su|journal=Chemical Physics Letters|volume=389|year=2004|page=83|doi=10.1016/j.cplett.2004.03.064}}</ref><ref>{{cite journal|title=A room temperature process for making Mn₂O₃ nano-particles and γ-MnOOH nano-rods|author=Navin Chandra, Sanjeev Bhasin, Meenakshi Sharma and Deepti Pal|journal=Materials Letters|volume=61|year=2007|page=3728|doi=10.1016/j.matlet.2006.12.024}}</ref>

Manganese (III) oxide is formed by the redox reaction in an alkaline cell:

: 2 MnO₂ + Zn → Mn₂O₃ + ZnO

Manganese (III) oxide Mn₂O₃ must not be confused with MnOOH manganese (III) oxohydroxide. Contrary to Mn₂O₃, MnOOH is a compound that decomposes at about 300°C to form MnO₂.<ref>{{cite journal|title=Hydrogen Bonding and Jahn-Teller Distortion in Groutite,α-MnOOH, and Manganite,γ-MnOOH, and Their Relations to the Manganese Dioxides Ramsdellite and Pyrolusite|author=Thomas Kohler, Thomas Armbruster, Eugen Libowitzky|journal=Journal of Solid State Chemistry|volume=133|year=1997|pages=486–500|doi=10.1006/jssc.1997.7516}}</ref>

Mn₂O₃ is unlike many other transition metal oxides in that it does not adopt the [[corundum]] ([[aluminium oxide|Al₂O₃]]) structure.<ref name = "Greenwood" /> Two forms are generally recognized, α-Mn₂O₃ and γ-Mn₂O₃,<ref name = "Wells">Wells A.F. (1984) ''Structural Inorganic Chemistry'' 5th edition Oxford Science Publications ISBN 0-19-855370-6</ref> although a high pressure form with the CaIrO₃ structure has been reported too.<ref>High Pressure Phase transition in Mn₂O₃ to the CaIrO₃-type Phase Santillan, J.; Shim, S. American Geophysical Union, Fall Meeting 2005, abstract #MR23B-0050</ref>

α-Mn₂O₃ has the cubic [[bixbyite]] structure, which is an example of a C-type rare earth sesquioxide ([[Pearson symbol]] cI80, space group Ia3, #206). The [[bixbyite]] structure has been found to be stabilised by the presence of

small amounts of Fe³⁺, pure Mn₂O₃ has an orthorhombic structure ([[Pearson symbol]] oP24,space group Pbca, #61).<ref>{{cite journal|title=Structure of α-Mn₂O₃, (Mn_0.983Fe_0.017)₂O₃ and (Mn_0.37Fe_0.63)₂O₃ and relation to magnetic ordering|author=Geller S.|journal=Acta Cryst|year=1971|volume=B27|page=821|doi=10.1107/S0567740871002966}}</ref>

γ-Mn₂O₃ has a structure related to the spinel structure of [[manganese(II,III) oxide|Mn₃O₄]] where the oxide ions are cubic close packed. This is similar to the relationship between [[iron(III) oxide|γ-Fe₂O₃]] and [[iron(II,III) oxide|Fe₃O₄]].<ref name = "Wells"/> γ-Mn₂O₃ is ferrimagnetic with a Neel temperature of 39 K.<ref>{{cite journal|title=Ferrimagnetism in γ-Manganese Sesquioxide (γ−Mn₂O₃) Nanoparticles|author=Kim S. H, Choi B. J ,Lee G.H., Oh S. J., Kim B., Choi H. C., Park J, Chang Y.|journal=Journal of the Korean Physical Society|volume=46|issue=4|year=2005|page=941}}</ref>

[[Category:Manganese compounds]]

[[Category:Oxides]]

[[Category:Manganese minerals]]

[[de:Mangan(III)-oxid]]

[[pl:Tlenek manganu(III)]]

[[simple:Manganese(III) oxide]]