Abstract: The invention relates to novel fluorinated organic compounds having the following molecular structure: ##STR1## where R.sub.F is a fluorinated carbon chain, R.sub.1H is hydrogen or a saturated hydrogenated carbon chain, R.sub.2H is hydrogen or a saturated hydrogenated carbon chain, R.sub.1H and R.sub.2H being not simultaneously hydrogen, the group ##STR2## comprising a principal chain and at least one linear or cyclic branch. These compounds may be prepared by reacting a phosphine with a halide under heating, and then hot reacting in a solvent the resulting phosphonium salt with a branched aldehyde or a ketone. These compounds have an excellent stability, a good biocompatibility and a high capacity to solubilize gases and particularly oxygen, such properties allowing their use in applications of the ophthalmological type or as an organ preservation medium.