New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer
In this study, a homologous series of novel liquid crystalline compounds bearing the bis-azomethine central linkage (–CH=N-N=CH–), namely ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4,1-phenylene) dialkanoate (<b>I<i>n</i></b>), was synthesized, and the mesophas...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-03-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/6/1256 |
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| author | Fowzia S. Alamro Hoda A. Ahmed Noha S. Bedowr Muna S. Khushaim Mohamed A. El-atawy |
| author_facet | Fowzia S. Alamro Hoda A. Ahmed Noha S. Bedowr Muna S. Khushaim Mohamed A. El-atawy |
| author_sort | Fowzia S. Alamro |
| collection | DOAJ |
| description | In this study, a homologous series of novel liquid crystalline compounds bearing the bis-azomethine central linkage (–CH=N-N=CH–), namely ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4,1-phenylene) dialkanoate (<b>I<i>n</i></b>), was synthesized, and the mesophase and thermal properties were investigated theoretically and experimentally. The molecular structures of the prepared compounds were determined using elemental analysis, NMR, and FT-IR spectroscopy. The mesophase transitions were detected by differential scanning calorimetry (DSC), and the mesophases were identified using polarized optical microscopy (POM). The results indicated that the derivative with the shortest length (<b>I<i>5</i></b>) was purely nematogenic, while the other homologues (<b>I<i>9</i></b> and <b>I<i>15</i></b>) possessed SmC mesophases. The optimal geometrical structures of the investigated group were derived theoretically. The estimated results demonstrated that all homologues were mesomorphic, and their type depended on the length of the terminal chains. Computations based on density functional theory (DFT) were used to explain the experimental data. The calculated dipole moment, polarizability, thermal energy, and molecular electrostatic potential all showed that it was possible to predict the mesophase type and stability, which varied according to the size of the molecule. |
| first_indexed | 2024-03-09T12:51:55Z |
| format | Article |
| id | doaj.art-5fbf93bb53b74211b97d2e504a5597e5 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T12:51:55Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-5fbf93bb53b74211b97d2e504a5597e52023-11-30T22:04:48ZengMDPI AGPolymers2073-43602022-03-01146125610.3390/polym14061256New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central SpacerFowzia S. Alamro0Hoda A. Ahmed1Noha S. Bedowr2Muna S. Khushaim3Mohamed A. El-atawy4Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi ArabiaDepartment of Chemistry, Faculty of Science, Cairo University, Cairo 12613, EgyptChemistry Department, College of Sciences, Taibah University, Yanbu 30799, Saudi ArabiaDepartment of Physics, Faculty of Science, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi ArabiaChemistry Department, College of Sciences, Taibah University, Yanbu 30799, Saudi ArabiaIn this study, a homologous series of novel liquid crystalline compounds bearing the bis-azomethine central linkage (–CH=N-N=CH–), namely ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4,1-phenylene) dialkanoate (<b>I<i>n</i></b>), was synthesized, and the mesophase and thermal properties were investigated theoretically and experimentally. The molecular structures of the prepared compounds were determined using elemental analysis, NMR, and FT-IR spectroscopy. The mesophase transitions were detected by differential scanning calorimetry (DSC), and the mesophases were identified using polarized optical microscopy (POM). The results indicated that the derivative with the shortest length (<b>I<i>5</i></b>) was purely nematogenic, while the other homologues (<b>I<i>9</i></b> and <b>I<i>15</i></b>) possessed SmC mesophases. The optimal geometrical structures of the investigated group were derived theoretically. The estimated results demonstrated that all homologues were mesomorphic, and their type depended on the length of the terminal chains. Computations based on density functional theory (DFT) were used to explain the experimental data. The calculated dipole moment, polarizability, thermal energy, and molecular electrostatic potential all showed that it was possible to predict the mesophase type and stability, which varied according to the size of the molecule.https://www.mdpi.com/2073-4360/14/6/1256bis-azomethine liquid crystalsmesomorphic propertiesgeometrical structureDFT |
| spellingShingle | Fowzia S. Alamro Hoda A. Ahmed Noha S. Bedowr Muna S. Khushaim Mohamed A. El-atawy New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer Polymers bis-azomethine liquid crystals mesomorphic properties geometrical structure DFT |
| title | New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer |
| title_full | New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer |
| title_fullStr | New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer |
| title_full_unstemmed | New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer |
| title_short | New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer |
| title_sort | new advanced liquid crystalline materials bearing bis azomethine as central spacer |
| topic | bis-azomethine liquid crystals mesomorphic properties geometrical structure DFT |
| url | https://www.mdpi.com/2073-4360/14/6/1256 |
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