Hafnium(IV) iodide

Hafnium(IV) iodide
Names
IUPAC name
Hafnium(IV) iodide
Other names
hafnium tetraiodide, tetraiodohafnium
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.150.349 Edit this at Wikidata
EC Number
  • 621-502-1
  • InChI=1S/Hf.4HI/h;4*1H/q+4;;;;/p-4
    Key: YCJQNNVSZNFWAH-UHFFFAOYSA-J
  • I[Hf](I)(I)I
Properties
HfI4
Molar mass 686.11[1]
Appearance red-orange[1]
Density 5.60 g/cm3[1]
Melting point 449 °C (840 °F; 722 K)[1]
Boiling point 394 °C (741 °F; 667 K)[1] (sublimes)
Structure
Monoclinic, mS40
C2/c, No. 15[2]
a = 1.1787 nm, b = 1.1801 nm, c = 1.2905 nm
Related compounds
Other anions
 Hafnium(IV) fluoride
Hafnium(IV) chloride
Hafnium(IV) bromide
Other cations
 Titanium(IV) iodide
Zirconium(IV) iodide
Related compounds
 Hafnium(III) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Hafnium(IV) iodide is the inorganic compound with the formula HfI4. It is a red-orange, moisture sensitive, sublimable solid that is produced by heating a mixture of hafnium with excess iodine.[2] It is an intermediate in the crystal bar process for producing hafnium metal.

In this compound, the hafnium centers adopt octahedral coordination geometry. Like most binary metal halides, the compound is a polymeric. It is one-dimensional polymer consisting of chains of edge-shared bioctahedral Hf2I8 subunits, similar to the motif adopted by HfCl4. The nonbridging iodide ligands have shorter bonds to Hf than the bridging iodide ligands.[2]

References

  1. ^ a b c d e Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, Florida: CRC Press. p. 4.66. ISBN 1-4398-5511-0.
  2. ^ a b c Krebs, B.; Sinram, D. (1980). "Hafniumtetrajodid HfI4: Struktur und eigenschaften. Ein neuer AB4-strukturtyp". Journal of the Less Common Metals. 76 (1–2): 7–16. doi:10.1016/0022-5088(80)90005-3.