Terbium(III,IV) oxide

Terbium(III,IV) oxide, occasionally called tetraterbium heptaoxide, has the formula Tb₄O₇, though some texts refer to it as TbO_1.75. There is some debate as to whether it is a discrete compound, or simply one phase in an interstitial oxide system. Tb₄O₇ is one of the main commercial oxides: Tb₂O₃, TbO₂, and Tb₆O₁₁.

Synthesis

Tb₄O₇ is most often produced by ignition of the oxalate at or the sulfate in air.^[1] The oxalate (at 1000 °C) is generally preferred, since the sulfate requires a higher temperature, and it produces an almost black product contaminated with Tb₆O₁₁ or other oxygen-rich oxides.

Chemical properties

Terbium(III,IV) oxide loses H₂) with air, leading to incandescence and often the mixture catches fire.^[2]

Tb₄O₇ reacts with atomic oxygen to produce TbO₂, but a more convenient preparation of TbO₂ is by hydrochloric acids for 30 minutes.^[3]

Tb₄O₇(l)

Tb₄O₇ reacts with other hot concentrated acids to produce terbium(III) salts, for example sulfuric acid gives terbium(III) sulfate.

References

1. ^  Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
2. ^  J. W. Mellor, A Comprehensive Treatise on Inorganic and Theoretical Chemistry, pp 692-696, Longmans, Green & Co., London, 1967.
3. ^ Gmelin SE C 1 39, p 397.
4. ^  D. W. Bissel, C. James, J. Am. Chem. Soc 38, 873 (1916).
5. ^  F. T. Edelmann, P. Poremba, in: Synthetic Methods of Organometallic and Inorganic Chemistry, (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997. ISBN 3-13-103071-2.