Hafnium(IV) Chloride

Hafnium(IV) chloride is the inorganic compound with the formula HfCl₄. This colourless solid is the precursor to most hafnium organometallic compounds. It functions as a Lewis acid and catalyst for certain alkylation and isomerism reactions. Hafnium the metal center in the complex occurs in nature in small amounts associated with Zirconium minerals such as zircon, cyrtolite and baddeleyite. Zircon contains 0.05 to 2.0 percent Hafnium oxide HfO₂, cyrtolite with 5.5 to 17 percent HfO₂ and baddeleyite contains 1.0 to 1.8 percent HfO₂.

Hafnium and zirconium compounds are extracted from ores together because Hafnium and Zirconium have very similar chemical and physical properties. Therefore in the synthesis of Hafnium(IV) chloride which requires HfO₂, the HfO₂ has to be purified from the mineral ore and this can be achieved through decomposition.