Technetium(VII) oxide

Technetium(VII) oxide
	; Structural formula of technetium(VII) oxide.
	; Unit cell of technetium(VII) oxide.
Names
	IUPAC name Technetium(VII) oxide
	Other names Technetium heptoxide
Identifiers
CAS Number	12165-21-8 ;
3D model (JSmol)	Interactive image;
PubChem CID	22227441;
CompTox Dashboard (EPA)	DTXSID70153330 ;
	InChI InChI=1S/7O.2Tc/q7-2;2+7;
	SMILES O=[Tc](=O)(=O)O[Tc](=O)(=O)=O;
Properties
Chemical formula	Tc2O7
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)
Solubility in water	hydrolysis to HTcO4
Magnetic susceptibility (χ)	−40.0·10−6 cm3/mol
Structure
Crystal structure	Primitive orthorhombic
Space group	Pbca, No. 61
Lattice constant	a = 1375.6 pm, b = 743.9 pm, c = 561.7 pm
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	radioactive
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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 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

References

^ ^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.
^ 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.
^ 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.