Hexafluorotitanic acid

Hexafluorotitanic acid (systematically named oxonium hexafluoridotitanate(2-)) is an inorganic compound with the chemical formula (H₃O)(H₅O₂)[TiF₆]. According to X-ray crystallography, the salt consists of [TiF₆]^2- octahedral and two kinds of oxonium cations, (H₃O)⁺ and (H₅O₂)⁺.^[1]

Hexafluorotitanic acid

Names
IUPAC name Hexafluorotitanic acid
Identifiers
CAS Number	anhydrous: 17439-11-1 N[ECHA]
3D model (JSmol)	anhydrous: Interactive image
ChemSpider	anhydrous: 19989125
ECHA InfoCard	100.037.676
EC Number	anhydrous: 241-460-4
PubChem CID	anhydrous: 161221
CompTox Dashboard (EPA)	anhydrous: DTXSID70893446
InChI Key: PFSXARRIPPWGNC-UHFFFAOYSA-J anhydrous: InChI=1/6FH.Ti/h6*1H;/q;;;;;;+4/p-4/f6F.Ti.2H/h6*1h;;;/q6*-1;m;2*+1
SMILES anhydrous: [H+].[H+].F[Ti-2](F)(F)(F)(F)F
Properties
Chemical formula	F6H8O3Ti
Molar mass	217.918 g·mol−1
Appearance	colorless solid
Density	2.10 g/cm3
Related compounds
Other anions	Hexafluorosilicic acid Ammonium hexafluorotitanate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

As with most oxonium salts, it is only stable in acidic solution. Under basic conditions, closely related salts hydrolyse to a hydrated titanium dioxide:^[2]

(NH₄)₂TiF₆ + 4 NH₃ + 2 H₂O → TiO₂ + 6 NH₄F

A related salt is the anhydrous fluoronium hexafluoridotitanate(2-) or (H₂F)₂[TiF₆].