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

Abstract

Herein, a new homologues series of fluorinated liquid crystal compounds, In, 4-(((4-fluorophenyl)imino)methyl)-2-methoxyphenyl 4-alkoxybenzoate were synthesized and its mesomorphic properties were investigated both experimentally and theoretically. The synthesized compounds were characterized by elemental analyzer, NMR, and FT-IR spectroscopy to deduce the molecular structures. The differential scanning calorimetry was employed to examine mesophase transitions whereas the polarized optical microscopy was used to identify the mesophases. The obtained results revealed that the purely nematic phase observed in all terminal side chains. All homologues showed to possess monotropic nematic mesophases except the derivative I8 exhibits enantiotropic property. The optimized geometrical structures of the present designed groups have been derived theoretically. The experimental data was explained using density functional theory computations. The estimated values of dipole moment, polarizability, thermal energy, and molecule electrostatic potential demonstrated that the mesophase stability and type could be illustrated. Binary phase diagram was constructed and addressed in terms of the mesomorphic temperature range and obtained polymorphic phases. It was found that incorporation of the terminal F-atom and lateral CH3O group influence both conformation and steric effect in pure and mixed states. The absorption and fluorescence emission spectra of fabricated films were recorded to elucidate the impact of terminal side chain on photophysical properties of synthesized liquid crystal. It was noted that the increase of terminal side chain length lead to reduction of optical band gap, whereas charge carrier lifetime increases.

New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer

“…Table 1 and Figure 3 reveal that the derivate with the shortest alkyl chain ( I 5 ) exhibited pure nematic (N) phase, while the other two longer homologues ( I 9 and I 15 ) were smectogenic and possessed the SmC mesophases. Generally, the mesomorphic behavior of any designed liquid crystalline molecular architecture is determined by the type of linking spacers, the length of the terminal chains, and the size of the attached substituents [ 34 , 35 ]. The melting transitions followed a random pattern, as seen in Table 1 and Figure 3 .…”

“…These results are in accordance with previous findings [ 34 ]. In addition, the terminal alkyl chains play an important role in multiconformational changes in the molecule [ 35 ].…”

Experimental and Theoretical Investigations of Three-Ring Ester/Azomethine Materials

“…Within the hard core of the molecule, the Schiff base (azomethine group) is employed as a connecting group. Despite having a stepped core structure, the azomethine group retains molecular linearity, which makes the molecule more stable and, in most cases, allows the formation of the mesophase [ 27 ].…”

Novel Imidazole Liquid Crystals; Experimental and Computational Approaches

“…Different azomethine/ester homologous series of liquid crystals (LCs) have been thoroughly researched to appreciate the relation between chemical structure and mesomorphic attributes because of their unique mesomorphic properties [ 37 , 38 , 39 , 40 , 41 ]. An organic molecule’s molecular shape generally affects the mesophase stability and temperature ranges it can withstand; even a little alteration in molecular geometry can have a significant impact on mesomorphic behavior [ 42 ].Moreover, the Schiff base (azomethine group) serves as a connecting group within the molecule’s rigid core.…”