Zirconium perchlorate

Zirconium perchlorate is an inorganic compound with the formula Zr(ClO₄)₄. It is a hygroscopic colorless solid that sublimes in a vacuum at 70 °C. These properties show that the compound is covalently bonded molecule, rather than a salt.^[1] It is an example of a transition metal perchlorate complex.^[2]

Zirconium perchlorate

Identifiers
3D model (JSmol)	Interactive image
InChI InChI=1S/4ClHO4.Zr/c4*2-1(3,4)5;/h4*(H,2,3,4,5);/q;;;;+4/p-4 Key: MQGNWZLWQBTZJR-UHFFFAOYSA-J
SMILES [Zr](O[Cl](=O)(=O)=O)(O[Cl](=O)(=O)=O)(O[Cl](=O)(=O)=O)O[Cl](=O)(=O)=O
Properties
Chemical formula	Cl4O16Zr
Molar mass	489.01 g·mol−1
Appearance	white crystals, deliquescent
Melting point	96 °C (205 °F; 369 K)
Boiling point	decomposition
Solubility in water	decomposition
Related compounds
Other anions	Zirconium nitrate Zirconyl perchlorate
Other cations	Titanium perchlorate Hafnium perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis and properties

It can be formed by treating zirconium tetrachloride with dichlorine hexoxide-perchloric acid mixture at −35 °C.^[1]

Zirconium perchlorate reacts irreversibly with most organic compounds but is inert towards carbon tetrachloride, chloroformide. With benzene at -10°C, crystals of Zr(ClO₄)₄•C₆H₆ are deposited.

Solid zirconium perchlorate undergoes a phase transition around 45 °C before melting between 95.5 and 96.0 °C. Thermolysis near 120 °C gives zirconyl perchlorate. Further heating around 290°C gives form zirconia and chlorine oxides.^[1]

Structure

In the gas phase the Zr(ClO₄)₄ molecule has a D₄ symmetry with eightfold square antiprism oxygen coordination. Each perchorate group is bidentate. The chlorine atoms are in a tetrahedral arrangement around the central zirconium.^[3]

In the solid phase, Zr(ClO₄)₄ crystals are monoclinic with a=12.899, b=13.188, c=7.937 Å, β=107.91°. There are four molecules per unit cell.^[4]

Related substances

Titanium perchlorate and hafnium perchlorate are both known.^[2]

Salts of perchloratozirconates and hexaperchloratozirconates have been claimed including the caesium perchloratozirconates CsZr(ClO₄)₅, Cs₂Zr(ClO₄)₆, and Cs₄Zr(ClO₄)₈.^[5][6]

Zirconyl perchlorates have been claimed in older literature.^[7]