Compounds of formula (I) and formula (III): ##STR00001## wherein A is --F or --CF.sub.3; R.sub.f is independently C.sub.1-C.sub.6 perfluorinated linear or branched alkyl optionally interrupted by one or more oxygens; R.sub.o is a linear or branched aliphatic group of about 10 to about 100 carbon atoms, interrupted by about 5 to about 50 ether oxygens, wherein the ratio of ether oxygen to carbon atoms is about 1:2 to about 1:3; and wherein each carbon atom has at most one ether oxygen atom bonded to it, and covalent bonding between ether oxygen atoms is absent; m is an integer of 1 to 3; Y.sup.-m is an anionic radical selected from the group consisting of halide, C.sub.1-C.sub.6 carboxylate, carbonate, hydrocarbonate, sulfate, hydrosulfate, C.sub.1-C.sub.6 sulfonate, phosphate, hydrophosphate, and dihydrophosphate. Further embodiments include methods of lowering surface tension of a medium comprising contacting the medium with a composition of formula (I), (III), or a mixture thereof.