High Quality Content by WIKIPEDIA articles! Trifluoromethyl is a functional group in organofluorines that has the formula -CF3. The naming of is group is derived from the methyl group (which has the formula -CH3), by replacing each hydrogen atom by a fluorine atom. The trifluomethyl group has a significant electronegativity that is often described as being intermediate between the electronegativities of fluorine and chlorine. For this reason, trifluoromethyl-substituted compounds are often strong acids, such as trifluoromethanesulfonic acid and trifluoroacetic acid. In other cases, the trifluoromethyl group is employed to lower the basicity of organic compounds or to confer distinctive solvation properties (e.g. trifluoroethanol).