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

A homologous set of liquid crystalline materials (Tn) bearing Schiff base/ester linkages were prepared and investigated via experimental and theoretical techniques. Terminal flexible groups of different chain lengths were connected to the end of phenylbenzoate unit while the other end of molecules w...

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Autores principales: Alamro, Fowzia S., Ahmed, Hoda A., Popoola, Saheed A., Aboelnaga, Asmaa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8588046/
https://www.ncbi.nlm.nih.gov/pubmed/34770826
http://dx.doi.org/10.3390/molecules26216416
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author Alamro, Fowzia S.
Ahmed, Hoda A.
Popoola, Saheed A.
Aboelnaga, Asmaa
author_facet Alamro, Fowzia S.
Ahmed, Hoda A.
Popoola, Saheed A.
Aboelnaga, Asmaa
author_sort Alamro, Fowzia S.
collection PubMed
description A homologous set of liquid crystalline materials (Tn) bearing Schiff base/ester linkages were prepared and investigated via experimental and theoretical techniques. Terminal flexible groups of different chain lengths were connected to the end of phenylbenzoate unit while the other end of molecules was attached to the heterocyclic pyridine moiety. The molecular structures of the designed molecules were evaluated by FT-IR, NMR spectroscopic analyses, whereas their mesomorphic properties were investigated by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). They all exhibited dimorphic properties with the exception of the members having the shortest and longest terminal flexible chains (n = 6 and 16), which were monomorphic. The T16 derivative was further found possessing purely smectic A (SmA) mesophase while others have their lengths covered by nematic (N) phase. Moreover, the computational evaluation of the azomethine derivatives was carried out using a DFT approach. The polarity of the investigated derivatives was predicted to be appreciably sensitive to the size of the system. Furthermore, the Frontier molecular orbitals analysis revealed various distributions of electron clouds at HOMO and LUMO levels.
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spelling pubmed-85880462021-11-13 Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System Alamro, Fowzia S. Ahmed, Hoda A. Popoola, Saheed A. Aboelnaga, Asmaa Molecules Article A homologous set of liquid crystalline materials (Tn) bearing Schiff base/ester linkages were prepared and investigated via experimental and theoretical techniques. Terminal flexible groups of different chain lengths were connected to the end of phenylbenzoate unit while the other end of molecules was attached to the heterocyclic pyridine moiety. The molecular structures of the designed molecules were evaluated by FT-IR, NMR spectroscopic analyses, whereas their mesomorphic properties were investigated by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). They all exhibited dimorphic properties with the exception of the members having the shortest and longest terminal flexible chains (n = 6 and 16), which were monomorphic. The T16 derivative was further found possessing purely smectic A (SmA) mesophase while others have their lengths covered by nematic (N) phase. Moreover, the computational evaluation of the azomethine derivatives was carried out using a DFT approach. The polarity of the investigated derivatives was predicted to be appreciably sensitive to the size of the system. Furthermore, the Frontier molecular orbitals analysis revealed various distributions of electron clouds at HOMO and LUMO levels. MDPI 2021-10-24 /pmc/articles/PMC8588046/ /pubmed/34770826 http://dx.doi.org/10.3390/molecules26216416 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Alamro, Fowzia S.
Ahmed, Hoda A.
Popoola, Saheed A.
Aboelnaga, Asmaa
Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title_full Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title_fullStr Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title_full_unstemmed Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title_short Synthesis, Phase Behavior and Computational Simulations of a Pyridyl-Based Liquid Crystal System
title_sort synthesis, phase behavior and computational simulations of a pyridyl-based liquid crystal system
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8588046/
https://www.ncbi.nlm.nih.gov/pubmed/34770826
http://dx.doi.org/10.3390/molecules26216416
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