Gadolinium(III) iodide

Gadolinium(III) iodide is an iodide of gadolinium, with the chemical formula of GdI3. It is a yellow, highly hygroscopic solid with a bismuth(III) iodide-type crystal structure. In air, it quickly absorbs moisture and forms hydrates. The corresponding oxide iodide is also readily formed at elevated temperature.[2]

Gadolinium(III) iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard100.033.619 Edit this at Wikidata
EC Number
  • 236-997-6
  • InChI=1S/Gd.3HI/h;3*1H/q+3;;;/p-3
    Key: IZZTUGMCLUGNPM-UHFFFAOYSA-K
  • [I-].[I-].[I-].[Gd+3]
Properties
GdI3
Molar mass537.96 g/mol−1
Appearanceyellow solid
Melting point926 °C[1]
Boiling point1340 °C[2]
Hazards
GHS labelling:
GHS07: Exclamation markGHS08: Health hazard
Danger[1]
H317, H360
P201, P280, P308+P313[1]
Related compounds
Other anions
Gadolinium(III) fluoride
Gadolinium(III) chloride
Gadolinium(III) bromide
Other cations
Europium(III) iodide
Terbium(III) iodide
Samarium(III) iodide
Related compounds
Gadolinium(II) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation

Gadolinium(III) iodide can be obtained by reacting gadolinium with iodine:[2]

2 Gd + 3 I2 → 2 GdI3

It can also be obtained by reacting gadolinium with mercury(II) iodide in a vacuum at 500 °C:[2]

2 Gd + 3 HgI2 → 2 GdI3 + 3 Hg

Gadolinium(III) iodide can be obtained by the reaction between gadolinium(III) oxide and hydroiodic acid, crystallizing into the hydrate form. The hydrate form can be heated with ammonium iodide to form the anhydrous form.[2][3]

Gd2O3 + 6 HI → 2 GdI3 + 3 H2O

Reactions

Gadolinium(III) iodide reacts with gadolinium and zinc in an argon atmosphere heated to 850 °C to obtain Gd7I12Zn.[4] It reacts with gadolinium, carbon, and gadolinium nitride in a tantalum tube at 897 °C to obtain nitrocarbide Gd4I6CN.[5]

References

External reading

  • Asprey, L. B.; Keenan, T. K.; Kruse, F. H. Preparation and crystal data for lanthanide and actinide triiodides. Inorg. Chem., 1964. 3 (8): 1137-1240