Triflate

In organic chemistry, triflate (systematic name: trifluoromethanesulfonate), is a functional group with the formulaR−OSO₂CF₃ and structureR−O−S(=O)₂−CF₃. The triflate group is often represented by −OTf, as opposed to −Tf, which is the triflyl group, R−SO₂CF₃. For example, n-butyl triflate can be written as CH₃CH₂CH₂CH₂OTf.

The corresponding triflate anion, CF₃SO−3, is an extremely stable polyatomic ion; this comes from the fact that triflic acid (CF₃SO₃H) is a superacid; i.e. it is more acidic than pure sulfuric acid, already one of the strongest acids known.