Fluoroantimonic acid
Fluoroantimonic acid HFSbF
5 is a mixture of
hydrofluoric acid and
antimony pentafluoride, and is the strongest known
superacid system. In this system, hydrofluoric acid releases the proton (H
+), and the
conjugate base (F
âˆ') is effectively sequestered by forming a strong coordinate bond with the fluorophilic antimony pentafluoride. The result of this coordinated bond is a large octahedral
anion (SbF
6âˆ'), which is a very weak nucleophile and a very weak base. The proton effectively becomes a "free proton", which accounts for the system's extreme acidity. Fluoroantimonic acid is 2(twenty quintillion) times stronger than 100% sulfuric acid. The autodissociation of fluoroantimonic acid in water and dissociation back to its constituents can be abbreviated as |
Fluoroantimonic_acid.jpeg |
Comparison with other acids
* Fluoroantimonic acid (1990) (Ho Value = - 31.3)
* Magic acid (1974) (Ho Value = - 19.2)
* Carborane superacid (1969) (Ho Value = - 18.0)
* Fluorosulfuric acid (1944) (Ho Value = - 15.1)
* Triflic acid (1940) (Ho Value = - 14.9)
