Einsteinium(III) oxide

Einsteinium(III) oxide

__ Es^3+     __ O^2−
Names
IUPAC names Einsteinium sesquioxide Dieinsteinium trioxide Einsteinium(III) oxide
Identifiers
CAS Number	37362-94-0
Properties
Chemical formula	Es2O3
Molar mass	554 g/mol (^253Es)
Appearance	colourless solid[1]
Structure
Crystal structure	Hexagonal
Space group	Ia3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Einsteinium(III) oxide is an oxide of the synthetic actinide einsteinium which has the molecular formula Es₂O₃. It is a colourless solid.^[1]

Three modifications are known. The body-centered cubic form has lattice parameter a = 1076.6 ± 0.6 pm; this allows the ionic radius of the Es³⁺ ion to be calculated as 92.8 pm.^[2] The other two forms are monoclinic and hexagonal: the hexagonal form has the lanthanum(III) oxide structure.^[3]

Einsteinium(III) oxide can be obtained by annealing einsteinium(III) nitrate in sub-microgram quantities.^[2]

References

1. Arnold F. Holleman, Nils Wiberg: Lehrbuch der Anorganischen Chemie, 102nd Edition, de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1, p. 1972.
2. R. G. Haire, R. D. Baybarz: "Identification and Analysis of Einsteinium Sesquioxide by Electron Diffraction", in: Journal of Inorganic and Nuclear Chemistry, 1973, 35 (2), S. 489–496; doi:10.1016/0022-1902(73)80561-5.
3. R. G. Haire, L. Eyring, in: Handbook on the Physics and Chemistry of Rare Earths, Vol. 18 Lanthanoids and Actinides Chemistry (hrsg. von K. A. Gscheidner, Jr., L. Eyring, G. R. Choppin, G. H. Lander), North-Holland, New York 1994, S. 414–505.

Further reading

• Haire, Richard G. (2006). "Einsteinium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean. The Chemistry of the Actinide and Transactinide Elements (PDF) 3 (3rd ed.). Dordrecht, the Netherlands: Springer. pp. 1577–1620. doi:10.1007/1-4020-3598-5_12.