Determination of molecular parameters of the MHPB(H)PBC and MHPB(F)PBC antiferroelectric liquid crystals

Two investigated antiferroelectric liquid crystals, MHPB(H)PBC and MHPB(F)P BC. were synthesized [1] and some their physical properties were described earlier [2]. Apart of the above, MHPB(H)PBC and MHPB(F)PBC have been studie d by means of dielectric, densitometric, refractometric and X-ray measureme nts. Spontaneous polarization P-S and tilt angle theta in ferro- (SmC*) and antiferroelectric (SMCA*) phases of MHPB(H)PBC and MHPB(F)PBC have also be en investigated. Transverse oct and longitudinal al molecular polarizabilit ies have been calculated front the ordinary n(o) and extraordinary n(e) ref ractive indices and density rho of MHPB(H)PBC and MHPB(F)PBC, using Neugeba uer's, Vuks and Lorentz equations with both Haller and Subramhanyama extrap olation procedures. Effective values of the molecular dipole moment p have been calculated from electric permittivity E in the 1 phases of these compo unds, using Maier and Meier equation.