What is "trifluoromethanesulfonate"

Trifluoromethanesulfonate, also known by the trivial name triflate, is a functional group with the formula CFSO−. The triflate group is often represented by −OTf, as opposed to −Tf ( triflyl). For example, n-butyl triflate can be written as CHCHCHCHOTf.

The triflate anion, is an extremely stable polyatomic ion, being the conjugate base of triflic acid (CFSOH), one of the strongest acids known. It is defined as a superacid, because it is more acidic than pure sulfuric acid.