Strong acids, process for the preparation thereof, and uses thereof

#The present invention relates to acids of the general formula [I]

#where y=1, 2 or 3, and in which the ligands R may be identical or different, and R is a perfluorinated C1-8-alkyl or aryl group or R is a partially fluorinated C1-8-alkyl or aryl group in which some of the F or H may have been substituted by chlorine.

#The present invention furthermore relates to a process for the preparation of the acids according to the invention, to salts comprising a cation and the anion of one of the acids according to the invention, and to a process for the preparation of the salts. The invention furthermore relates to the use of the acids and metal salts according to the invention.

#3.74 g of water were added to 3.14 g of a 40% by weight aqueous hydrofluoric acid (62.8 mmol of HF) (in total 312.1 mmol of water) in an FEP (fluoroethylene polymer) flask. After this mixture had been cooled in an ice bath, 26.55 g (62.3 mmol) of difluorotris(pentafluoroethyl)phosphorane were added over the course of 2 minutes while stirring using a magnetic stirrer. All the phosphorane had dissolved within 3 minutes, and a colourless, clear solution of aqueous acid [(C2F5)3PF3]−H+ had formed. 33.4 g of an 83.2% by weight trifluorotris(pentafluoroethyl)phosphoric acid solution were prepared in virtually quantitative yield.

#The compound conforms to the formula: [(C2F5)3PF3]−H+.5H2O.

#The solution was analysed by 19F NMR spectroscopy. The spectra were measured using an FEP tube with an acetone-D6 film as external lock and CCl3F as external reference.