Rhenium(VII) oxide

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Rhenium(VII) oxide
Rhenium(VII) oxide
Names
Other names
Rhenium heptoxide
Identifiers
1314-68-7 YesY
Jmol interactive 3D Image
PubChem 123106
Properties
O7Re2
Molar mass 484.40298 g/mol
Appearance yellow crystalline powder
Density 6.103 g/cm3, solid
Melting point 360 °C (680 °F; 633 K)
Boiling point sublimes
Hazards
not listed
Related compounds
Related compounds
Manganese(VII) oxide; technetium(VII) oxide; perrhenic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Rhenium(VII) oxide is the inorganic compound with the formula Re2O7. This yellowish solid is the anhydride of HOReO3. Perrhenic acid, Re2O7·2H2O, is closely related to Re2O7. Re2O7 is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore.[1]

Structure[edit]

Crystalline Re2O7 is an inorganic polymer, which consists of alternating octahedral and tetrahedral Re centres. Upon heating, the polymer cracks to give molecular (nonpolymeric) Re2O7. This molecular species closely resembles manganese heptoxide, consisting of a pair of ReO4 tetrahedra that share a vertex, i.e., O3Re-O-ReO3.[2]

Synthesis and reactions[edit]

Rhenium(VII) oxide is formed when metallic rhenium or its oxides or sulfides are oxidized at 500-700 °C in air.:[3]

Re2O7 is very reactive toward water. It dissolves in water to give perrhenic acid. It is a precursor to methylrhenium trioxide ("MTO"), a catalyst for oxidations.[4]

Uses[edit]

Hydrogenation Catalyst[edit]

Rhenium(VII) oxide finds some use in organic synthesis as a catalyst for carbonyl reduction and amide reduction.[5]

See also[edit]

References[edit]

  1. ^ Hans Georg Nadler "Rhenium and Rhenium Compounds" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2000. doi:10.1002/14356007.a23_199
  2. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  3. ^ Schmidt, M.; Schmidbaur, H., "Trimethylsilyl perrhenate", Inorg. Synth. 1967, 9, 149-151. doi:10.1002/9780470132401.ch40
  4. ^ W. A. Herrmann and F. E. Kuhn (1997). "Organorhenium Oxides". Acc. Chem. Res. 30 (4): 169–180. doi:10.1021/ar9601398. 
  5. ^ Nishimura, Shigeo (2001). Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis (1st ed.). Newyork: Wiley-Interscience. pp. 42–43, 182, 389–390, & 408. ISBN 9780471396987.