The boiling points of the 15 chlorofluorocarbons based on methane are shown to be determined by the structural parameters of the number of chlorines, the number of fluorines, and the dipole moment. The melting points of these 15 compounds also depend on molecular symmetry and specifically by inclusion of the rotational entropy. The success of this structure-property relation would suggest that these molecules have close to free rotation in the liquid, despite their high dipole moments.