Synthesis, Optical and DFT Characterizations of Laterally Fluorinated Phenyl Cinnamate Liquid Crystal Non-Symmetric System

Abstract

A new laterally fluorinated unsymmetric liquid crystalline homologous series, based on cinnamate linkage, named 2-fluoro-4-(4-(alkoxy)phenyl)diazenyl)phenyl cinnamate (In), was synthesized and evaluated via different experimental and computational tools. The series had different terminal alkoxy-chain lengths with a lateral F atom in the meta position with respect to the azo moiety. The experimental mesomorphic and optical investigations were carried out using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Theoretical calculations and geometrical parameter predictions were conducted using the DFT program method at B3LYP/6-311G** level of theory. The results revealed that all the designed compounds exhibited the nematic (N) mesophase enantiotropically. The nematic stability and temperature range were impacted by the terminal alkoxy chain length. Compounds with the shortest chains (I6 and I8) showed a monotropic smectic A (SmA) phase, while the longest chain derivative, I16, possessed enantiotropic Sm A phase. Theoretical density functional theory (DFT) predictions were correlated with the practically observed data from the mesomorphic investigations. Data revealed that the terminal alkoxy and lateral F groups had an essential impact on the total energy of possible geometrical structures and their physical and thermal parameters.

Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System

“…Compounds T6, T8, T10, T12, T14 and T16 were prepared according to Scheme 1: Details of preparation and spectroscopic characterizations are given in Supplementary Information (Figures S1-S5). ular polarizability, as well as the geometrical parameters of each prepared compound, a DFT approach was used and the results were correlated with the experimental data [33][34][35][36][37][38][39][40]. It is essential to note that the DFT calculations assume a gas phase for all molecules, as such the most favorable predicted geometry could differ from that of empirical which occurs in a condensed phase such as LC mesophase, where more prolonged molecules are usually favored [41].…”

New Self-Organizing Optical Materials and Induced Polymorphic Phases of Their Mixtures Targeted for Energy Investigations

“…The molecules, on the other hand, tend to orientate in a parallel arrangement as the length of the terminal substituent grows [ 26 ]. Furthermore, the twist-bend nematic and heliconical phases are influenced by the length of the terminal chains [ 27 , 28 , 29 , 30 ].…”

Synthesis, Optical Characterizations and Solar Energy Applications of New Schiff Base Materials

“…Consequently, the selection of the flexible alkoxy/alkyl groups, terminal wings, as well as mesogenic linkers, is an important criterion in the formation of thermotropic LCs for proper characteristic industries. Moreover, the molecular shape enables some essential changes in the mesomorphic characteristics and plays an important role in the formation, kind, and thermal stability of the formed mesophase [9][10][11][12][13][14][15][16].…”

“…Previously, based on Schiff base/ester central linkages, sets of terminal substituted derivatives were synthesized and investigated for their mesomorphic properties; in addition, the effect of the terminal long and compact group polarities on the mesophase were also studied [9][10][11][12][13][14][15][16]. On this basis, the goal of the present study is to synthesize new laterally methoxy Schiff base derivatives, with different terminal polar compact groups (X), namely, 4-(((4-(hexyloxy)phenyl)imino)methyl)-3-methoxyphenyl 4-substituted benzoates I6 a-e .…”