Technetium(VII) oxide


Technetium(VII) oxide is the chemical compound with the formula Tc2O7. This yellow volatile solid is a rare example of a molecular binary metal oxide, the other examples being RuO4, OsO4, and the unstable Mn2O7. It adopts a centrosymmetric corner-shared bi-tetrahedral structure in which the terminal and bridging Tc−O bonds are 167pm and 184 pm respectively and the Tc−O−Tc angle is 180°.[2]

Technetium(VII) oxide
Structural formula of technetium(VII) oxide.
Unit cell of technetium(VII) oxide under standard conditions.
Unit cell of technetium(VII) oxide.
IUPAC name
Technetium(VII) oxide
Other names
Technetium heptoxide
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3D model (JSmol)
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  • InChI=1S/7O.2Tc/q7*-2;2*+7
  • [O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Tc+7].[Tc+7]
Molar mass 307.810 g/mol
Appearance light yellow solid
Density 3.5 g/cm3
Melting point 119.5 °C (247.1 °F; 392.6 K)
Boiling point 310.6 °C (591.1 °F; 583.8 K)
hydrolysis to HTcO4
−40.0·10−6 cm3/mol
Primitive orthorhombic
Pbca, No. 61
a = 1375.6 pm, b = 743.9 pm, c = 561.7 pm[1]
Occupational safety and health (OHS/OSH):
Main hazards
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

Technetium(VII) oxide is prepared by the oxidation of technetium at 450–500 °C:[3]

4 Tc + 7 O2 → 2 Tc2O7

It is the anhydride of pertechnetic acid and the precursor to sodium pertechnetate:

Tc2O7 + 2 H2O → 2 HTcO4
Tc2O7 + 2 NaOH → 2 NaTcO4 + H2O


  1. ^ a b Krebs, Bernt (1971). "Technetium(VII)-oxid: Ein Übergangsmetalloxid mit Molekülstruktur im festen Zustand". Zeitschrift für anorganische und allgemeine Chemie. 380 (2): 146–159. doi:10.1002/zaac.19713800205.
  2. ^ Krebs, Bernt (1969). "Technetium(VII)-oxid: Ein Übergangsmetalloxid mit Molekülstruktur im festen Zustand". Angewandte Chemie. 81 (9): 328–329. Bibcode:1969AngCh..81..328K. doi:10.1002/ange.19690810905.
  3. ^ Herrell, A. Y.; Busey, R. H.; Gayer, K. H. (1977). Technetium(VII) Oxide, in Inorganic Syntheses. Vol. XVII. pp. 155–158. doi:10.1002/9780470132487.ch41. ISBN 0-07-044327-0.