Manganese(VII) oxide (manganese heptoxide) is an inorganic compound with the formula Mn2O7. Manganese heptoxide is a volatile liquid with an oily consistency. It is a highly reactive and powerful oxidizer that reacts explosively with nearly any organic compound. It was first described in 1860.[1] It is the acid anhydride of permanganic acid.
The crystalline form of this chemical compound is dark green. The liquid is green by reflected light and red by transmitted light.[2] It is soluble in carbon tetrachloride, and decomposes when in contact with water.
Structureedit
Its solubility properties indicate a nonpolar molecular species, which is confirmed by its structure. The molecules consist of a pair of tetrahedra that share a common vertex. The vertices are occupied by oxygen atoms and at the centers of the tetrahedra are the Mn(VII) centers. The connectivity is indicated by the formula O3Mn−O−MnO3. The terminal Mn−O distances are 1.585 Å and the bridging oxygen is 1.77 Å distant from the two Mn atoms. The Mn−O−Mn angle is 120.7°.[3]
Pyrosulfate, pyrophosphate, and dichromate adopt structures similar to that of Mn2O7. Probably the most similar main group species is Cl2O7. Focusing on comparisons within the transition metal series, Tc2O7 and Mn2O7 are structurally similar but the Tc−O−Tc angle is 180°. Solid Re2O7 is not molecular but consists of crosslinked Re centers with both tetrahedral and octahedral sites;[4] in the vapour phase it is molecular with a similar structure to Tc2O7.[5]
Synthesis and reactionsedit
Mn2O7 arises as a dark green oil by the addition of cold concentrated H2SO4 to solid KMnO4.[2] The reaction initially produces permanganic acid, HMnO4 (structurally, HOMnO3), which is dehydrated by cold sulfuric acid to form its anhydride, Mn2O7.
2 KMnO4 + 2 H2SO4 → Mn2O7 + H2O + 2 KHSO4
Mn2O7 can react further with sulfuric acid to give the remarkable manganyl(VII) cation MnO+ 3, which is isoelectronic with CrO3
Mn2O7 + 2 H2SO4 → 2 [MnO 3]+ [HSO 4]− + H2O
Mn2O7 decomposes near room temperature, explosively so above 55 °C. The explosion can be initiated by striking the sample or by its exposure to oxidizable organic compounds. The products are MnO2 and O2.[6]Ozone is also produced, giving a strong smell to the substance. The ozone can spontaneously ignite a piece of paper impregnated with an alcohol solution.
^Aschoff, H. Ann. Phys. Chem. Ser. 2 volume 111 (1860) page 217 and page 224.
^ abH. Lux (1963). "Manganese(VII) Oxide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. pp. 1459–1460.
^Simon, A.; Dronskowski, R.; Krebs, B.; Hettich, B. (1987). "The Crystal Structure of Mn2O7". Angew. Chem. Int. Ed. Engl.26 (2): 139–140. doi:10.1002/anie.198701391.
^Krebs, B.; Mueller, A.; Beyer, H. H. (1969). "The Crystal Structure of Rhenium(VII) Oxide". Inorganic Chemistry. 8 (3): 436–443. doi:10.1021/ic50073a006.
^Wells A.F. (1962) Structural Inorganic Chemistry 3d edition Oxford University Press
^Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN0-12-352651-5.
April 13, 2024
manganese, heptoxide, manganese, oxide, manganese, heptoxide, inorganic, compound, with, formula, mn2o7, volatile, liquid, with, oily, consistency, highly, reactive, powerful, oxidizer, that, reacts, explosively, with, nearly, organic, compound, first, describ. Manganese VII oxide manganese heptoxide is an inorganic compound with the formula Mn2O7 Manganese heptoxide is a volatile liquid with an oily consistency It is a highly reactive and powerful oxidizer that reacts explosively with nearly any organic compound It was first described in 1860 1 It is the acid anhydride of permanganic acid Manganese VII oxide NamesIUPAC name Manganese VII oxideOther names Manganic oxide dimanganese heptoxidePermanganic anhydride Permanganic oxideIdentifiersCAS Number 12057 92 0 Y3D model JSmol Interactive imageChemSpider 9944714ECHA InfoCard 100 031 829EC Number 235 025 8PubChem CID 13879826CompTox Dashboard EPA DTXSID10894891InChI InChI 1S 2Mn 7O q 7 2Key ZEFXULJEOUCCOQ UHFFFAOYSA NSMILES O Mn O O O Mn O O OPropertiesChemical formula Mn2O7Molar mass 221 87 g molAppearance dark red oil room temp green if in contact with sulfuric acidDensity 2 79 g cm3Melting point 5 9 C 42 6 F 279 0 K Boiling point explodes on heatingSolubility in water decomposes to permanganic acid HMnO4StructureCrystal structure monoclinicCoordination geometry bitetrahedralHazardsOccupational safety and health OHS OSH Main hazards explosive strong oxidizer very corrosiveGHS labelling PictogramsSignal word DangerHazard statements H201 H271 H314 H330Precautionary statements P260 P284 P283 P221NFPA 704 fire diamond 444OXRelated compoundsRelated compounds Re2O7 KMnO4 Tc2O7 Cl2O7Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Properties 2 Structure 3 Synthesis and reactions 4 ReferencesProperties editThe crystalline form of this chemical compound is dark green The liquid is green by reflected light and red by transmitted light 2 It is soluble in carbon tetrachloride and decomposes when in contact with water Structure editIts solubility properties indicate a nonpolar molecular species which is confirmed by its structure The molecules consist of a pair of tetrahedra that share a common vertex The vertices are occupied by oxygen atoms and at the centers of the tetrahedra are the Mn VII centers The connectivity is indicated by the formula O3Mn O MnO3 The terminal Mn O distances are 1 585 A and the bridging oxygen is 1 77 A distant from the two Mn atoms The Mn O Mn angle is 120 7 3 Pyrosulfate pyrophosphate and dichromate adopt structures similar to that of Mn2O7 Probably the most similar main group species is Cl2O7 Focusing on comparisons within the transition metal series Tc2O7 and Mn2O7 are structurally similar but the Tc O Tc angle is 180 Solid Re2O7 is not molecular but consists of crosslinked Re centers with both tetrahedral and octahedral sites 4 in the vapour phase it is molecular with a similar structure to Tc2O7 5 Synthesis and reactions editMn2O7 arises as a dark green oil by the addition of cold concentrated H2SO4 to solid KMnO4 2 The reaction initially produces permanganic acid HMnO4 structurally HOMnO3 which is dehydrated by cold sulfuric acid to form its anhydride Mn2O7 2 KMnO4 2 H2SO4 Mn2O7 H2O 2 KHSO4Mn2O7 can react further with sulfuric acid to give the remarkable manganyl VII cation MnO 3 which is isoelectronic with CrO3 Mn2O7 2 H2SO4 2 MnO3 HSO4 H2OMn2O7 decomposes near room temperature explosively so above 55 C The explosion can be initiated by striking the sample or by its exposure to oxidizable organic compounds The products are MnO2 and O2 6 Ozone is also produced giving a strong smell to the substance The ozone can spontaneously ignite a piece of paper impregnated with an alcohol solution Manganese heptoxide reacts with hydrogen peroxide in presence of sulfuric acid liberating oxygen and ozone 2 Mn2O7 2 H2O2 4 H2SO4 4 MnSO4 6 H2O 2 O3 3 O2References edit Aschoff H Ann Phys Chem Ser 2 volume 111 1860 page 217 and page 224 a b H Lux 1963 Manganese VII Oxide In G Brauer ed Handbook of Preparative Inorganic Chemistry 2nd Ed Vol 1 NY NY Academic Press pp 1459 1460 Simon A Dronskowski R Krebs B Hettich B 1987 The Crystal Structure of Mn2O7 Angew Chem Int Ed Engl 26 2 139 140 doi 10 1002 anie 198701391 Krebs B Mueller A Beyer H H 1969 The Crystal Structure of Rhenium VII Oxide Inorganic Chemistry 8 3 436 443 doi 10 1021 ic50073a006 Wells A F 1962 Structural Inorganic Chemistry 3d edition Oxford University Press Holleman A F Wiberg E Inorganic Chemistry Academic Press San Diego 2001 ISBN 0 12 352651 5 Retrieved from https en wikipedia org w index php title Manganese heptoxide amp oldid 1208735786, wikipedia, wiki, book, books, library,
