Titanium tetrafluoride

Titanium(IV) fluoride is the inorganic compound with the formula TiF₄. It is a white hygroscopic solid. In contrast to the other tetrahalides of titanium, it adopts a polymeric structure.^[2] In common with the other tetrahalides, TiF₄ is a strong Lewis acid.

Titanium(IV) fluoride

Titanium(IV) fluoride
Names
IUPAC name Titanium(IV) fluoride
Other names Titanium tetrafluoride
Identifiers
CAS Number	7783-63-3 Y
3D model (JSmol)	Interactive image
ChemSpider	7988529 Y
ECHA InfoCard	100.029.106
EC Number	232-017-6
PubChem CID	121824
UNII	T08RW8YRG1 Y
CompTox Dashboard (EPA)	DTXSID50894996
InChI InChI=1S/4FH.Ti/h4*1H;/q;;;;+4/p-4 Y Key: XROWMBWRMNHXMF-UHFFFAOYSA-J Y InChI=1/4FH.Ti/h4*1H;/q;;;;+4/p-4 Key: XROWMBWRMNHXMF-XBHQNQODAM
SMILES F[Ti](F)(F)F
Properties
Chemical formula	TiF4
Molar mass	123.861 g/mol
Appearance	white powder
Density	2.798 g/cm3
Melting point	377 °C (711 °F; 650 K)
Boiling point	sublimes
Hazards
GHS labelling:[1]
Pictograms
Signal word	Danger
Hazard statements	H302, H312, H314, H332
Precautionary statements	P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P322, P330, P363, P405
NFPA 704 (fire diamond)	3 0 0
Related compounds
Other anions	Titanium(IV) bromide Titanium(IV) chloride Titanium(IV) iodide
Related compounds	Titanium(III) fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation and structure

The traditional method involves treatment of titanium tetrachloride with excess hydrogen fluoride:^[3]

TiCl₄ + 4 HF → TiF₄ + 4 HCl

Purification is by sublimation, which involves reversible cracking of the polymeric structure.^[4] X-ray crystallography reveals that the Ti centres are octahedral, but conjoined in an unusual columnar structure.^[5]

Reactions

Structure of the [Ti₄F₁₈]^2- dianion

TiF₄ forms adducts with many ligands. One example is the complex cis-TiF₄(CH₃CN)₂, which is formed by treatment with acetonitrile.^[6] It is also used as a reagent in the preparation of organofluorine compounds.^[7] With fluoride, the cluster [Ti₄F₁₈]^2- forms. It has an adamantane-like Ti₄F₆ core.^[8]

Related to its Lewis acidity, TiF₄ forms a variety of hexafluorides also called hexafluorotitanates. Hexafluorotitanic acid has been used commercially to clean metal surfaces. These salts are stable at pH<4 in the presence of hydrogen fluoride, otherwise they hydrolyze to give oxides.^[3]