Dielectric Studies of Inter-and Intramolecular Motions in the Nematic and Isotropic Phases of 7CP5BOC

The dielectric relaxation of 7CP5BOC (2-chloro-4-heptylphenly 4-pentylbicyclo-[2,2,2]octan-l-car-boxylate) in its isotropic and nematic phase has been studied. The substance has a negative dielectric anisotropy. The complex dielectric permittivity was measured in the frequency range 10 kHz -3 GHz with the aid of an impedance analyzer and a time domain spectroscopy (TDS) method. The relaxation time, activation enthalpy and dielectric increments, characterizing the rotation of the molecules about the principal inertia axes, were obtained. It was found that the relaxation process connected with rota-tions about the long axis can be split into two independent motions of molecular moieties around the