Some advantages are provided by the use of cryogenic solvents in order to study the spectroscopy of volatile fluorinated molecules. For instance, the lowering of the temperature, by slowing down the rotation, greatly simplifies the spectra, leading to narrow absorption peaks. The solvent transparency (N2, O2, rare gases), enables us to operate in more diluted condition (10−7 molar ratio) than it would be the case in a solid matrix. With such dilutions, the molecule is generally observed as a monomer, thus allowing the study of naturally associated forms. The study of chemical reactions is made possible since the diffusion of the molecules of solute is not hindered as it would be the case in a solid matrix. The use of low temperatures from 70 to 160 K allows the study of chemical reaction with low activation energies, it also allows the stabilization of otherwise thermally unstable species. These properties related to the use of cryogenic solutions, are illustrated in our paper, with some simple fluorinated molecules such as : CF3I, COF2, SF6 [1], SF4 (fig. 1), SiF4 (fig. 2) ... The coupling between levels, and the isotopic effects of heavy atoms are amongst the examples illustrated.