scholarly journals New wide-stability four-ring azo/ester/Schiff base liquid crystals: synthesis, mesomorphic, photophysical, and DFT approaches

RSC Advances ◽  
2020 ◽  
Vol 10 (16) ◽  
pp. 9643-9656 ◽  
Author(s):  
Nagwa H. S. Ahmed ◽  
Gamal R. Saad ◽  
Hoda. A. Ahmed ◽  
Mohamed Hagar
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Base Liquid ◽  
Dsc Thermograms

DSC thermograms of some prepared compounds: (a) recorded from second heating and (b) from cooling at a rate of ±10 °C min−1.

scholarly journals Polar Alkoxy Group and Pyridyl Effects on the Mesomorphic Behavior of New Non-Symmetrical Schiff Base Liquid Crystals

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1832
Author(s):  
Sayed Z. Mohammady ◽  
Daifallah M. Aldhayan ◽  
Mohammed A. Alshammri ◽  
Ayoub K. Alshammari ◽  
Mohammed Alazmi ◽  
...  
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Chain Length ◽  
Density Functional ◽  
Theoretical Calculations ◽  
13C Nmr Spectroscopy ◽  
Alkoxy Group ◽  
Thermal Stabilities ◽  
New Compounds ◽  
Base Liquid

A series of non-symmetrical Schiff base liquid crystals were prepared and investigated. Schiff bases of p-alkyloxy aniline derivatives and 4-phenyl pyridine-4′-carbaldehyde were synthesized. The terminal alkoxy groups substituting aniline are of varied chain length, namely C6, C8, and C16. The structures of the compounds were confirmed via 1H NMR and 13C NMR spectroscopy. Different mesophases of the samples were thermally and optically characterized by differential thermal analysis (DSC) and polarized optical microscopy (POM). All samples revealed enantiotropic smectic B (SmB) and smectic A (SmA) mesophases. The results obtained were further correlated with the density functional theory (DFT) theoretical calculations. The results are compared to a series of compounds bearing biphenyl moiety in their mesogens. The thermal stabilities of the different mesophase reduced upon the increment of the alkoxy chain length. The temperature ranges of both the smectic mesophases of new compounds bearing the 4-phenyl pyridine moiety are generally expanded higher than the other series. In addition, the total mesophase range is greater in the new compounds when compared to their biphenyl analogues. The DFT results were investigated in terms of the molecular geometries and the frontier molecular orbitals as well as the charge distribution mapping to show and illustrate the difference in the mesomorphic properties.

New two rings Schiff base liquid crystals; ball mill synthesis, mesomorphic, Hammett and DFT studies

2020 ◽  
Vol 299 ◽  
pp. 112161 ◽  
Author(s):  
Sherif S. Nafee ◽  
Mohamed Hagar ◽  
Hoda A. Ahmed ◽  
O.A. Alhaddad ◽  
Reda M. El-Shishtawy ◽  
...  
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Ball Mill ◽  
Dft Studies ◽  
Base Liquid

Influence of meta-extended rigid-core, complementary hydrogen bonding and flexible chain on polymorphism in Schiff-base liquid crystals: (4)MeOBD(3)AmBA:nOBAs

2019 ◽  
Vol 47 (4) ◽  
pp. 582-603
Author(s):  
AVSN Krishna Murthy ◽  
M. Srinivasulu ◽  
AVN Ashok Kumar ◽  
YV Rao ◽  
DM Potukuchi
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Base ◽  
Liquid Crystals ◽  
Rigid Core ◽  
Flexible Chain ◽  
Base Liquid

SF5-Terminated Fluorinated Schiff Base Liquid Crystals

2004 ◽  
Vol 108 (52) ◽  
pp. 19940-19948 ◽  
Author(s):  
Jeremy A. Smith ◽  
Robert A. DiStasio ◽  
Nicole A. Hannah ◽  
Rolf W. Winter ◽  
Timothy J. R. Weakley ◽  
...  
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Base Liquid

scholarly journals Schiff Base liquid Crystals with Terminal Alkoxy Group Synthesis and Thermotropic Properties

2017 ◽  
Vol 17 (2) ◽  
pp. 64-72 ◽  
Author(s):  
Nasreen R. Jber ◽  
◽  
Mohammad M. Shukur ◽  
Ahmed A. Najaf ◽  
◽  
...  
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Alkoxy Group ◽  
Thermotropic Properties ◽  
Base Liquid
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