Sodium trifluoroacetate


Sodium trifluoroacetate is a chemical compound with a formula of CF3CO2Na. It is the sodium salt of trifluoroacetic acid. It is used as a source of trifluoromethylations.

Basicity

With the pKa of 0.23 for trifluoroacetic acid, the trifluoroacetate ion is clearly a much weaker base. This is because of the electron-withdrawing effect on the 3 fluorine atoms adjacent to the carbon atom. With strong acids, such as hydrochloric acid or sulfuric acid, the trifluoroacetate ion can be protonated:

It also partially reacts with hydronium cations to form the acid:
The equilibrium is not complete because of the smaller pKa difference of the acid and hydronium.

Preparation

One convenient method is by dissolving an equivalent amount of sodium carbonate in 50% aqueous solution of trifluoroacetic acid. The solution is filtered and evaporated by vacuum evaporation. The solid obtained is dried under vacuum at 100 °C.

Uses

Sodium trifluoroacetate is a useful reagent for trifluoromethylation.