Trifluoroacetic acid Trifluoroacetic acid Trifluoroacetic acid (TFA) is an organofluorine compound with the chemical formula CFCOH. It is a structural analogue of acetic acid with all three of the acetyl group’s hydrogen atoms replaced by fluorine atoms and is a colorless liquid with a vinegar like odor. TFA is a stronger acid than acetic acid, having an acid ionisation constant that is approximately 34,000 times higher, as the highly electronegative fluorine atoms and consequent electron-withdrawing nature of the trifluoromethyl group weakens the oxygen-hydrogen bond (allowing for greater acidity) and stabilises the anionic conjugate base. TFA is widely used in organic chemistry for
Sulfonic acid Sulfonic acid A sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula R−S(=O)−OH, where R is an organic alkyl or aryl group and the S(=O)(OH) group a sulfonyl hydroxide. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, HS(=O)(OH), a tautomer of sulfurous acid, S(=O)(OH). Salts or esters of sulfonic acids are called sulfonates. A sulfonic acid is produced by the process of sulfonation. Usually