Use
Trifluoromethanesulfonic acid is a hygroscopic, colorless liquid at room temperature. It is soluble in polar solvents such as dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, and dimethyl sulfone. Addition of triflic acid to polar solvents can be dangerously exothermic.
Trifluoromethanesulfonic acid is widely used especially as a catalyst and a precursor in organic chemistry. With an Ka = 8. 0 1014 (pKa ~ -15) mol/kg, HOTf qualifies as a superacid. Triflic acid owes many of its useful properties to its great thermal and chemical stability. Both the acid and its conjugate base CF3SO3-, known as triflate, resist oxidation/reduction reactions, whereas many strong acids are oxidizing, e. g. HClO4 and HNO3. The triflate anion is immune to attack by even strong nucleophiles. Because of its resistance to oxidation and reduction, triflic acid is a very useful and versatile reagent. Further recommending its use, triflic acid does not sulfonate substrates, which can be a problem with sulfuric acid, fluorosulfuric acid, and chlorosulfonic acid. Below is a prototypical sulfonation, which HOTf does not undergo: C6H6 + H2SO4 C6H5(SO3H) + H2O.