Bifluoride


The bifluoride ion is an inorganic anion with the chemical formula.

Structure and bonding

The bifluoride ion has a linear, centrosymmetric structure, with an F−H bond length of 114 pm. The bond strength is estimated to be greater than 155 kJ/mol. In molecular orbital theory, the atoms are modeled to be held together by a 3-center 4-electron bond.

Acid-base properties and salts

In the reaction
the ion is acting as a Brønsted–Lowry base. This reaction can occur in non-aqueous solution. On the other hand, in the reaction
it is acting as an acid.
Salts, such as potassium bifluoride and ammonium bifluoride can be made in the direct reaction