Cerium diiodide

Cerium diiodide
Identifiers
3D model (JSmol)
  • InChI=1S/Ce.2HI/h;2*1H/q+2;;/p-2
    Key: ORCLLRHIKXTOMX-UHFFFAOYSA-L
  • [I-].[I-].[Ce+2]
Properties
CeI2
Molar mass 393.925 g·mol−1
Appearance bronze solid[1]
Melting point 808 °C[1]
Structure
I4/mmm (No. 139)
Related compounds
Other cations
 lanthanum diiodide
praseodymium diiodide
neodymium(II) iodide
Related compounds
 cerium(III) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Cerium diiodide is an iodide of cerium, with the chemical formula of CeI2.

Preparation

Cerium diiodide can be obtained from the reduction of cerium(III) iodide with metallic cerium under vacuum at 800 °C to 900 °C.[2]

Ce + 2 CeI3 → CeI2

It can also be formed from the reaction of cerium and ammonium iodide in liquid ammonia at −78 °C. The reaction forms an ammonia complex of cerium diiodide, which decomposes to cerium diiodide under vacuum at 200 °C.[2]

Ce + 2 NH4I → CeI2 + 2 NH3 + H2

It was first created by John D. Corbett in 1961.[3]

Properties

Cerium diiodide is an opaque dark solid with a metal-like appearance and properties. There is no cerium(II) in cerium diiodide, and its real structure is Ce3+(I−)2e−. It is easily hydrolyzed to form the corresponding iodide oxide.[2] Like lanthanum diiodide and praseodymium diiodide, the cerium diiodide forms in the MoSi2-type structure,[4] with space group I4/mmm (No. 139).[5]

References

  1. ^ a b Haynes, William (2012). CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. Boca Raton, Fla. London: CRC Taylor & Francis distributor. pp. 4–56. ISBN 978-1-4398-8049-4. OCLC 793213751.
  2. ^ a b c Handbuch der präparativen anorganischen Chemie (in German). Stuttgart: Enke. 1975. p. 1081. ISBN 3-432-02328-6. OCLC 310719485.
  3. ^ Jungmann, Angelika; Claessen, R.; Zimmermann, R.; Meng, Ge; Steiner, P.; Hüfner, S.; Tratzky, S.; Stöwe, K.; Beck, H. P. (1995). "Photoemission of LaI2 and CeI2". Zeitschrift für Physik B. 97 (1). Springer Science and Business Media LLC: 25–34. Bibcode:1995ZPhyB..97...25J. doi:10.1007/bf01317584. ISSN 0722-3277. S2CID 124057481.
  4. ^ Macintyre, J. E. (1992). Dictionary of inorganic compounds. London New York: Chapman & Hall. p. 2820. ISBN 0-412-30120-2. OCLC 26338506.
  5. ^ Hulliger, Fritz (1976). Structural chemistry of layer-type phases. Dordrecht, Holland Boston: D. Reidel Pub. Co. p. 247. ISBN 90-277-0714-6. OCLC 2372807.