The molecular and dielectric properties of tetrahalogenated methanes

For the investigation of the relations between dielectric properties and molecular characteristics, the tetrahalogenated methanes provide a series of molecules which deviate in shape only a little from that of a sphere and in dipole moment only a little from zero. The dielectric constants of many of them have been measured in the liquid and solid states over a wide range of temperature at a frequency of 5 kilocycles, and, when not too volatile for the available apparatus, their dielectric constants and losses have been measured in the liquid state at wavelengths of 1.24, 3.22 cm., and, occasionally, 10 cm., and used to calculate the critical wavelengths, at which the loss is a maximum, and the corresponding relaxation times. The molecular dipole moments have been calculated from the loss data, and the viscosities of the liquids have been measured.