Fluorophosphite is an ion with formula HPO2F−. The term is also used for salts contain the fluorophosphite anion.
The conjugate acid is phosphorofluoridous acid, (fluorophosphinic acid or monoflorophosphorous acid), H[PHO2F].
Production One way to produce is to react phosphonic acid with a fluoride salt in molten urea. This works with potassium and ammonium salts.
H3PO3 + O=C(NH2)2 + MF → M[PHO2F] + 2NH3 + CO2
Pyrophosphite is hydrolysed in a solution containing fluoride ions to fluorophosphite.
[H2P2O5]2− + HF → [HPO2F]− + [H2PO2]−
Phosphorus trifluoride combines with a dilute alkali bicarbonate solution to yield fluorophosphite.
A combination of hydrofluoric acid and monopotassium phosphite results in a solvated compound that is not a fluorophospite. Grinding potassium fluoride with phosphorous acid results in the same substance. It has formula KHPHO3•HF. When heated this produces some potassium fluorophosphite, along with potassium pyrophosphite.
KHPHO3•HF → KPFHO2 + H2O ↑
Lithium monofluorophosphite has been made from HF, phosphorus trichloride (PCl3) and lithium chloride, using ether as a solvent.
Reactions Fluorophosphite is hydrolysed by water to form more phosphite and hydrofluoric acid again. In neutral conditions, the concentration will of fluorophosphite will be similar to phosphite.
Fluorophosphite reacts with phosphate to yield a complex anion mixing PIII and PVI.
PO2H2F + H3PO4 ↔ HF + HP(O)(OH)OP(O)(OH)2
List formulareferenceLiPFHO2NH4PFHO2KPFHO2
References