Four compounds from 3FmHPhF homologous series of chiral smectogenic fluorinated compounds (m = 2, 4, 5, 6) were studied by frequency domain dielectric spectroscopy, electro-optic measurements, X-ray diffraction and differential scanning calorimetry. Values of the relaxation time and dielectric increment of relaxation processes versus temperature and bias field were determined. The temperature-dependent tilt angles, spontaneous polarisations, switching times, rotational viscosities, and average intermolecular distances and correlation lengths within smectic layers were obtained. Experimental results were supplemented by density functional theory calculations of isolated 3FmHPhF molecular geometries, and the relationship between the molecular structures and the transverse component of their dipole moments was studied for the mesogens with m = 2, 4, 5, 6, 7. The results are discussed in terms of the length of the C_mH_2m flexible carbon chain of the homologues.

Physical properties of the partially fluorinated compound 3F5FPhF, with hockey stick-like molecules, were studied by complementary methods. Apart from the already reported paraelectric SmA*, ferroelectric SmC* and antiferroelectric SmC*_A phases, the presence of the smectic C*_α subphase in the phase sequence was proved by differential scanning calorimetry, polarising optical microscopy, electro-optic and dielectric spectroscopy methods. The temperature dependence of the smectic layer thickness and correlation length of the lateral short-range order was determined by X-ray diffraction. Based on dielectric measurements three relaxation processes were revealed in the antiferroelectric SmC*_A phase (two collective: P_L, P_H and one molecular: s-process), two collective ones (Goldstone and soft modes) were found both in the ferroelectric SmC* phase and SmC*_α subphase while one relaxation process (soft mode) in the paraelectric SmA* phase. The results were compared with that obtained for other structurally similar compounds, and it was shown that even addition of one methylene group to the side chain influences much on the physical properties.

The phase transitions, crystallization kinetics and molecular dynamics of (S)-4′-(1-methylheptylcarbonyl)biphenyl-4-yl 4-[5-(2,2,3,3,4,4,4-heptafluorobutoxy)pent-1-oxy] benzoate (3F5HPhH6) are investigated by differential scanning calorimetry, polarizing optical microscopy and broadband dielectric spectroscopy. The vitrification of the antiferroelectric hexatic phase is observed for cooling rates ≥5 K min⁻¹ and the fragility index determined from dielectric data is m_f ≈ 90. Two regimes of non-isothermal cold crystallization are distinguished using the Kissinger and Augis–Bennett methods in the heating rate ranges of 1–5 K min⁻¹ (larger activation energy) and 8–20 K min⁻¹ (lower activation energy). The correlation between the time of non-isothermal cold crystallization (using isothermal approximation) and relaxation time of the α-process is determined. The obtained coupling coefficient ξ ≈ 0.7 and temperature dependence of the crystallization rate Z from the Ozawa model imply a mainly diffusion-controlled cold crystallization below 275 K. The Avrami exponents n and Ozawa exponents n_O determined for isothermal melt crystallization and non-isothermal cold crystallization, respectively, weigh in favour of two- rather than three-dimensional crystal growth. The transition between crystal phases is observed on heating, with a lower activation energy for 1–3 K min⁻¹ than for 5–20 K min⁻¹ rates.

Vitrification of the antiferroelectric smectic-${\mathrm{C}}_A^{*}$ phase is reported for the orthoconic mixture W-1000 and its new derivative W-356. The crystallization is not observed even upon slow cooling and the cold crystallization on subsequent heating is also absent. Molecular dynamics in the smectic phases of both mixtures is investigated down to 173 K and the fragility parameters are determined from the temperature behavior of the $\alpha$-process. X-ray diffraction is applied to compare the structural parameters of W-356 and W-1000 as well as to study the structural changes during the glass transition of the Sm-${\mathrm{C}}_A^{*}$ phase. The evolution of the smectic layer order within the Sm-${\mathrm{C}}_A^{*}$ glass is reported, while the correlation length of the short-range order in the smectic layers is shown to be almost constant below the glass transition temperature. Electrooptic properties of W-356: spontaneous polarization, tilt angle and switching time are determined and compared with these of W-1000. The observed differences between the properties of W-356 and W-1000 might be explained by the dimer formation of components with the -$\mathrm{C}\equiv \mathrm{N}$ terminal group, present only in the W-356 mixture, and by the different structure of the aromatic molecular core in one of the W-356 components.

Physical properties and the phase sequence of (S)-4′-(1-methylheptyloxycarbonyl)biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]-2-fluorobenzoate exhibiting the liquid crystalline paraelectric smectic A*, ferroelectric smectic C* and antiferroelectric smectic C_A* phases were studied by complementary methods in the temperature range from −125 to 120 °C. Differential scanning calorimetry measurements together with polarizing optical microscopy provided the phase sequence, including the glass transition and a cold crystallization. X-ray diffraction was used to obtain the unit-cell parameters of the crystal phase, as well as the layer thickness and correlation length in the liquid crystalline smectic phases. The tilt angle was found to reach 45°, as determined from the measurements of the layer thickness and molecular modeling. Relaxation processes in the smectic phases and the fragility parameter were studied using frequency-domain dielectric spectroscopy.