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 with a slight decomposition. It sublimes in a vacuum as low as 70 °C. Being a molecular with four perchlorate ligands, it is an unusual example of a transition metal perchlorate complex.

Titanium(IV) perchlorate

titanium perchlorate
Identifiers
CAS Number	60580-20-3[1] 13498-15-2
3D model (JSmol)	Interactive image
PubChem CID	14795113
InChI InChI=1S/4ClHO4.Ti/c4*2-1(3,4)5;/h4*(H,2,3,4,5);/q;;;;+4/p-4 Key: SOCDLWOJPVKBHF-UHFFFAOYSA-J
SMILES [Ti](O[Cl](=O)(=O)=O)(O[Cl](=O)(=O)=O)(O[Cl](=O)(=O)=O)O[Cl](=O)(=O)=O
Properties
Chemical formula	Ti(ClO4)4
Molar mass	445.65 g·mol−1
Appearance	white crystals, deliquescent
Density	2.49 g/cm3 (anhydrous)
Melting point	85 °C (185 °F; 358 K) (anhydrous) slight decomposition
Boiling point	decomposition
Solubility in water	high
Related compounds
Other anions	Titanium nitrate
Other cations	Zirconium 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

Properties

packing of Ti(ClO₄)₄ molecules in the crystal.

In Ti(ClO₄)₄, the four perchlorate groups binds as bidentate ligands. Thus the Ti center is bound to eight oxygen atoms.^[2] So the molecule could also be called tetrakis(perchlorato-O,O')titanium(IV).^[3]

In the solid form it forms monoclinic crystals, with unit cell parameters a=12.451 b=7.814 c=12.826 Å α=108.13. Unit cell volume is 1186 Å³ at -100 °C. There are four molecules per unit cell.^[1]

It reacts with petrolatum, nitromethane, acetonitrile, dimethylformamide, and over 25° with carbon tetrachloride.^[2]

Titanyl perchlorate form solvates with water, dimethyl sulfoxide, dioxane, pyridine-N-oxide, and quinoline-N-oxide.^[2]

Thermolysis of titanium perchlorate gives TiO₂, ClO₂ and dioxygen O₂ The titanyl species TiO(ClO₄)₂ is an intermediate in this decomposition.^[2]

Ti(ClO₄)₄ → TiO₂ + 4ClO₂ + 3O₂ ΔH = +6 kcal/mol (25 kJ/mol).^[2]

Formation

Titanium perchlorate can be formed by reacting titanium tetrachloride with perchloric acid enriched in dichlorine heptoxide.^[2] Another way uses titanium tetrachloride with dichlorine hexoxide. This forms a complex with Cl₂O₆ which when warmed to 55° in a vacuum, sublimes and can crystallise the pure anhydrous product from the vapour.^[1]

Related

In the salt dicaesium hexaperchloratotitanate, Cs₂Ti(ClO₄)₆ the perchlorate groups are monodentate, connected by one oxygen to titanium.^[4]

Titanium perchlorate can also form complexes with other ligands bound to the titanium atom including binol,^[5] and gluconic acid.^[6]

A polymeric oxychlorperchlorato compound of titanium, Ti₆O₄Cl_x(ClO₄)_16−x, is made from excess TiCl₄ and dichlorine hexoxide. This has a varying composition, and ranges from light to dark yellow.^[7]