Hafnium tetraiodide

Hafnium tetraiodide
Identifiers
13777-23-6
Properties
HfI4
Molar mass 686.11[1]
Appearance red-orange[1]
Density 5.60 g/cm3[1]
Melting point 449 °C[1]
Boiling point 394 °C (subl.)[1]
Structure
Crystal structure Monoclinic, mS40
Space group C2/c, No. 15[2]
Lattice constant a = 1.1787 nm, b = 1.1801 nm, c = 1.2905 nm
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Hafnium tetraiodide 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.[3] 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.[3]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.66. ISBN 1439855110.
  2. ↑ Krebs, B.; Sinram, D. (1980). "Hafniumtetrajodid HfI4: Struktur und eigenschaften. Ein neuer AB4-strukturtyp". Journal of the Less Common Metals 76: 7. doi:10.1016/0022-5088(80)90005-3.
  3. ↑ 3.0 3.1 Krebs, B.; Sinram, D. (1980). "Hafniumtetrajodid HfI4: Struktur und eigenschaften. Ein neuer AB4-strukturtyp". Journal of the Less Common Metals 76: 7. doi:10.1016/0022-5088(80)90005-3.