Bifluoride

Other names: hydrogen(difluoride) anion

[HF₂]^-

4/50 common

The bifluoride ion [HF₂]⁻ consists of a central hydrogen atom symmetrically bridging two fluoride ions (μ₂-bridging hydrogen), stabilized by exceptionally strong 3-center 4-electron symmetrical hydrogen bonding interaction. Bifluoride can essentially be thought of as a condensed conjugate base phase of hydrofluoric acid, a deadly yet invaluable chemical reagent used industrially for its ability to etch glass and silicon wafers.