Vaporization enthalpies of a series of the halogen-substituted fluorobenzenes

Vapor pressures of 2-, 3-, and 4-halogen-substituted fluorobenzenes (halogen = Cl, Br, and I) were measured by the transpiration method. Molar standard enthalpies of vaporization were calculated from temperature dependences of vapor pressures. New enthalpies of vaporization at 298 K and those available from literature were tested for consistency by correlation gas-chromatography and evaluated by group-additivity method. Contributions to vaporization due to mutual interactions of halogens on the benzene ring were derived and recommended for prediction vaporization enthalpies of halogen-substituted aromatics.