Fluoroboric acid

The term "fluoroboric acid" usually refers to a range of compounds including hydronium tetrafluoroborate ([H3O]+[BF4]−), which are available as solutions.

The ethyl ether solvate is also commercially available, where the fluoroboric acid can be represented by the formula [H((CH3CH2)2O)n]+[BF4]−, where n is 2.

It is a strong acid with a weakly coordinating, non-oxidizing conjugate base.

[2] It is structurally similar to perchloric acid, but lacks the hazards associated with oxidants.

These salts consist of protonated solvent as a cation, e.g., H3O+ and H5O+2, and the tetrahedral BF−4 anion.

[3] Titration of [N((CH2)3CH3)4]+[BF4]− (tetrabutylammonium tetrafluoroborate) in acetonitrile solution indicates that H[BF4], i.e., HF·BF3, has a pKa of 1.6 in that solvent.

The inorganic salts are intermediates in the manufacture of flame-retardant materials and glazing frits, and in electrolytic generation of boron.

Canonical, skeletal formula of oxonium tetrafluoroborate
Canonical, skeletal formula of oxonium tetrafluoroborate
NFPA 704 four-colored diamond Health 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gas Flammability 0: Will not burn. E.g. water Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen Special hazards (white): no code
Subunit of crystal structure of [H 3 O] + [BF 4 ] − highlighting the hydrogen bonding between the cation and the anion