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]
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]
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]
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]