Physical Chemistry of Binary Plastic Crystals. II. Dielectric Constant of the System, Carbon Tetrachloride and <i>t</i>-Butyl Chloride

Abstract

Abstract Careful measurements of the dielectric constant of a binary system of t-butyl chloride and carbon tetrachloride were made in the entire composition range and in three different phases, the liquid, the fee solid, and the rhombohedral phases. The simple Debye theory applies to the liquid and the fee solid, giving an effective dipole moment of t-butyl chloride of 2.11±0.01 D whereas in the rhombohedral phase, it was 2.00±0.03 D. Molecular polarization shows no discontinuity between the vapor, the liquid, and the fee solid but there is a jump between the fee and the rhombohedral solids. The molecular rotation in the plastic rhombohedral phase is more hindered by 450 cal/mol than in the liquid or the fee phase. The 1:1 solid solution data were examined on the basis of the Onsager theory.