BOILING-POINT OF TETRAHALOMETHANES

The plot of the boiling points of tetrahalomethanes versus the number of electrons in a molecule shows that the change in the boiling point on replacing one halogen atom with another is constant regardless of t he molecular structure. A comparison of the same plot for noble gas mo lecules shows that the contribution of each halogen atom in a molecule to the intermolecular interaction is comparable with that of the near est noble gas atom. This suggests that the whole intermolecular potent ial of tetrahalomethanes is dominated by noble gas-type dispersion int eractions. The effects of molecular and liquid structures, and polar i nteractions seem to be negligible.