Trifluoromethanesulfonic acid, also known as
triflic acid,
TFMS,
TFSA,
HOTf or
TfOH, is a
sulfonic acid with the chemical formula CF
3SO
3H. It is one of the strongest
acids. Triflic acid is mainly used in research as a
catalyst for
esterification. It is a
hygroscopic, colorless, slightly viscous liquid which is soluble in
polar solvents.