The trifluoromethyl group is a functional group 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. Some common examples are trifluoromethane H–CF
3, 1,1,1-trifluoroethane H
3C–CF
3, and hexafluoroacetone F
3C–CO–CF
3. Compounds with this group are a subclass of the organofluorines.