Synthesis and properties of antiferroelectric and/or ferroelectric compounds with the –CH₂O group close to chirality centre

Abstract

Third measurement of compound A.3.(HF)CH2O (S) was performed in cell 5 m thin with gold electrodes and planar alignment. Sample was cooled from the isotropic liquid down to the room temperature. DC field was sequentially applied starting from 0 V up to 10 V. Measurements were done for every 0.1 degree. Results of real part of permittivity versus temperature for several DC fields (500 Hz… 2.5 MHz) are presented below with the comments. Figures: A, B, C, D, E, F show results for DC fields: 0, 1, 2, 3, 4, 5 V respectively.Figure A. Real part  of permittivity versus temperature T for 12 measuring frequencies.Results for 0 V DC field.

The Influence of the Molecular Structure of Compounds on Their Properties and the Occurrence of Chiral Smectic Phases

“…Therefore, we designed mesogens with three benzene rings, without substituents on these rings, with a different number of methylene groups (n = 3 or 7), and with the chiral center: -CH 2 OC*H(CH 3 )OC 2 H 5 (S). These mesogens are structurally like previously synthesized compounds with antiferroelectric and/or ferroelectric phases [31,32]. The chemical formulas of the designed materials are shown in Figure 1a,b.…”

“…The MS yielded the following: 196(M + ), 123, 110, 93, 81, 73, 59, 45, and 28. This work aimed to synthesize and then study the mesomorphic properties of chiral smectic compounds and discuss the obtained results based on the properties of other compounds with a similar chemical structure [31,32], which were previously synthesized by the research group from the Military University of Technology. The article describes the characterizations of the mesophases obtained via polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and dielectric spectroscopy.…”

Molecular Dynamics and Kinetics of Isothermal Cold Crystallization in the Chiral Smectogenic 3F7FPhH6 Glassformer

“…Chiral liquid crystalline substances with three aromatic rings in a molecular core and partially fluorinated alkoxy chain [1][2][3][4][5][6][7][8] are desired materials in liquid crystal display (LCD) technology as they often exhibit a smectic C * A (SmC * A ) phase, showing antiferroelectric properties in the surface-stabilized geometry [9]. Moreover, the tilt angle in these compounds often approaches 45 • , which leads to the optical uniaxiality and, consequently, far better quality of the dark state compared to the SmC * A phase with the smaller tilt angle [10,11].…”

New-Generation Liquid Crystal Materials for Application in Infrared Region

“…It assumes that in order for a compound to exhibit liquid crystal properties, it must consist of a rigid core and appropriate substituents in the terminal and lateral positions. The most commonly used cores include derivatives of oligophenyls (e.g., terphenyl [ 40 , 41 ] and quaterphenyl [ 42 ]) and tolanes (e.g., phenyltolane [ 43 , 44 , 45 , 46 ] and bistolane [ 47 ]), which may also have other linking groups, e.g., ester and ether [ 48 ]. To obtain a suitable shape anisotropy, aliphatic chain(s) and/or strong dipole moment generating groups, such as cyano (CN) [ 49 ] and isothiocyanate (NCS) [ 50 , 51 ], are used as terminal substituents.…”