Fluorine Compounds, Inorganic, Phosphorus

Abstract

Phosphorus forms many fluorine compounds, including the binary fluorides, oxyfluorides, thiofluoride, and the various fluorophosphoric acids and their salts. Whereas PF 5 behaves as a Lewis acid, phosphorus trifluoride behaves as a Lewis base. PF 5 is used as a catalyst in the electronics industry and in ion implantation for semiconductors. The mono‐, di‐, and hexafluorophosphoric acids are commercially available. Hexafluorophosphoric acid is used in polymerization and preparation of its salts, a number of which exist. Particularly important commercially are sodium monofluorophosphate and potassium hexafluorophosphate, used as a dentifrice additive and as a catalyst for polymerization processes, respectively. The highly toxic fluorophosphate esters have found use in medical applications as well as in warfare. The polymerized esters are also known.