Protactinium(V) oxide
Protactinium(V) oxide
Names
IUPAC name
Protactinium(V) oxide
Identifiers
3D model (JSmol)
  • InChI=1S/5O.2Pa
    Key: LDJMPPCAULZCAH-UHFFFAOYSA-N
  • InChI=1S/10O.4Pa
    Key: YHCILLCTPZINHI-UHFFFAOYSA-N
  • O=[Pa](=O)O[Pa](=O)=O
  • O=[Pa]12O[Pa]3(=O)O[Pa](=O)(O1)O[Pa](=O)(O2)O3
Properties
Pa
2
O
5
Molar mass 542.0688 g mol−1
Appearance White, opaque crystals
Structure
cubic
Fm-3m, No. 225
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
highly toxic, radioactive
GHS labelling:
GHS06: Toxic
GHS08: Health hazard
GHS09: Environmental hazard
NFPA 704 (fire diamond)
4
0
0
Special hazard RA: Radioactive. E.g. plutonium
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Protactinium(V) oxide is a chemical compound with the formula Pa2O5. When it is reduced with hydrogen, it forms PaO2. Aristid V. Grosse was first to prepare 2 mg of Pa2O5 in 1927.[1] Pa2O5 does not dissolve in concentrated HNO3, but dissolves in HF and in a HF + H2SO4 mixture and reacts at high temperatures with solid oxides of alkali metal and alkaline earth metals.[2][3]: 195 

As protactinium(V) oxide, like other protactinium compounds, is radioactive, toxic and very rare, it has very limited technological use. Mixed oxides of Nb, Mg, Ga and Mn, doped with 0.005–0.52% Pa2O5, have been used as high temperature dielectrics (up to 1300 °C) for ceramic capacitors.[3]: 189 

References

  1. ^ "Protactinium".
  2. ^ Sellers, Philip A.; Fried, Sherman; Elson, Robert E.; Zachariasen, W. H. (1954). "The Preparation of Some Protactinium Compounds and the Metal". Journal of the American Chemical Society. 76 (23): 5935–5938. doi:10.1021/ja01652a011.
  3. ^ a b Boris F. Myasoedov, H. W. Kirby, & Ivan G. Tananaev (2006) Protactinium, Chapter 4 in Morss, Lester R. & Edelstein, Norman M. & Fuger, Jean, (edit.) The Chemistry of the Actinide and Transactinide Elements (PDF) (3. painos). Dordrecht: Springer. ss. 161–252.