Zirconium perchlorate is an

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

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

covalent A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atom ...

ly bonded molecule, rather than a salt. It is an example of a transition metal perchlorate complex.

Synthesis and properties

It can be formed by treating

zirconium tetrachloride Zirconium is a chemical element; it has symbol Zr and atomic number 40. First identified in 1789, isolated in impure form in 1824, and manufactured at scale by 1925, pure zirconium is a lustrous transition metal with a greyish-white color that c ...

with

dichlorine hexoxide Dichlorine hexoxide is the chemical compound with the molecular formula or , which is correct for its gaseous state. However, in liquid or solid form, this chlorine oxide ionizes into the dark red ionic compound chloryl perchlorate or dioxochlor ...

perchloric acid Perchloric acid is a mineral acid with the formula H Cl O4. It is an oxoacid of chlorine. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxid ...

mixture at −35 °C. Zirconium perchlorate reacts irreversibly with most organic compounds but is inert towards

carbon tetrachloride Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n ...

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

ide. With

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

at -10°C, crystals of Zr(ClO₄)₄•C₆H₆ are deposited. Solid zirconium perchlorate undergoes a

phase transition In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic Sta ...

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 Zirconium dioxide (), sometimes known as zirconia (not to be confused with zirconium silicate or zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral ba ...

and chlorine oxides.

Structure

In the gas phase the Zr(ClO₄)₄ molecule has a D₄ symmetry with eightfold

square antiprism In geometry, the square antiprism is the second in an infinite family of antiprisms formed by an even number, even-numbered sequence of triangle sides closed by two polygon caps. It is also known as an ''anticube''. If all its faces are regular ...

oxygen coordination. Each perchorate group is bidentate. The chlorine atoms are in a

tetrahedral In geometry, a tetrahedron (: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular Face (geometry), faces, six straight Edge (geometry), edges, and four vertex (geometry), vertices. The tet ...

arrangement around the central zirconium. In the solid phase, Zr(ClO₄)₄ crystals are

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

with a=12.899, b=13.188, c=7.937 Å, β=107.91°. There are four molecules per unit cell.

Related substances

Titanium perchlorate Titanium perchlorate, or more precisely titanium(IV) perchlorate, is a molecular compound of titanium and perchlorate groups with formula Ti(ClO4)4. Anhydrous titanium perchlorate decomposes explosively at 130 °C and melts at 85 °C wit ...

and hafnium perchlorate are both known. Salts of perchloratozirconates and hexaperchloratozirconates have been claimed including the caesium perchloratozirconates CsZr(ClO₄)₅, Cs₂Zr(ClO₄)₆, and Cs₄Zr(ClO₄)₈. Zirconyl perchlorates have been claimed in older literature.

References

{{perchlorates Zirconium(IV) compounds Perchlorates