Hafnium(IV) iodide is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

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 Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...

. It is an intermediate in the

crystal bar process A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macrosc ...

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.

References

{{Iodides Iodides Hafnium compounds Metal halides