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Alamro F, Ahmed HA, Alharbi NS, Al-Kadhi NS, Alhaddadd OA, Naoum MM, El-Atawy MA. Mesophase Behavior of Molecules Containing Three Benzene Rings Connected via Imines and Ester Linkages. ACS OMEGA 2024; 9:31601-31610. [PMID: 39072071 PMCID: PMC11270723 DOI: 10.1021/acsomega.4c01564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 06/21/2024] [Accepted: 07/02/2024] [Indexed: 07/30/2024]
Abstract
Ten new compounds based on the methineazo-azomethine (CH=N-N=CH) and ester linking groups were prepared and investigated for their mesophase behavior and optical stability, and liquid crystals of 4-substituted phenyl methineazo-azomethine phenyl 4-alkoxybenzoates, I n a-e , were investigated. An alkoxy group with a length between 8 and 12 carbons is attached to the phenyl eater wing, while the other terminal ring is substituted in its 4-position with one of the polar NO2, F, Cl, CH3O, and N(CH3)2 groups. The molecular structures of the newly prepared compounds were verified by using 1H NMR, 13C NMR, and elemental analysis. Differential scanning calorimetry and polarized optical microscopy were applied to investigate their mesophase behavior. All members of the prepared homologous series showed excellent thermal mesomorphic stability over wide temperature ranges. The geometrical and thermal properties of the investigated compounds were verified via density functional theory (DFT). The theoretical results revealed that all of the compounds are almost planar. Finally, the experimentally established values of the mesophase data were correlated with the predicted quantum chemical characteristics evaluated by DFT.
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Affiliation(s)
- Fowzia
S. Alamro
- Department
of Chemistry, College of Science, Princess
Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Hoda A. Ahmed
- Department
of Chemistry, Faculty of Science, Cairo
University, Cairo 12613, Egypt
| | - Nuha Salamah Alharbi
- Chemistry
Department, College of Science, Taibah University, Al-Madinah Almunawrah, Medina 30002, Saudi Arabia
| | - Nada S. Al-Kadhi
- Department
of Chemistry, College of Science, Princess
Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Omaima A. Alhaddadd
- Chemistry
Department, College of Science, Taibah University, Al-Madinah Almunawrah, Medina 30002, Saudi Arabia
| | - Magdi M. Naoum
- Department
of Chemistry, Faculty of Science, Cairo
University, Cairo 12613, Egypt
| | - Mohamed A. El-Atawy
- Chemistry
Department, Faculty of Science, Alexandria
University, P.O. Box 426, Ibrahemia, Alexandria 21321, Egypt
- Chemistry
Department, College of Sciences, Taibah
University, Yanbu 30799, Saudi Arabia
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Cruickshank E. The Emergence of a Polar Nematic Phase: A Chemist's Insight into the Ferroelectric Nematic Phase. Chempluschem 2024; 89:e202300726. [PMID: 38452282 DOI: 10.1002/cplu.202300726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/20/2024] [Accepted: 03/07/2024] [Indexed: 03/09/2024]
Abstract
The discovery of a new polar nematic phase; the ferroelectric nematic, has generated a great deal of excitement in the field of liquid crystals. To date there have been around 150 materials reported exhibiting the ferroelectric nematic phase, in general, following three key archetypal structures with these compounds known as RM734, DIO and UUQU-4N. In this review, the relationship between the molecular structure and the stability of the ferroelectric nematic, NF, phase will be described from a chemist's perspective. This will look to highlight the wide variety of functionalities which have been incorporated into these archetypal structures and how these changes influence the transition temperatures of the mesophases present. The NF phase appears to be stabilised particularly by reducing the length of terminal alkyl chains present and adding fluorines laterally along the length of the molecular backbone. This review will look to introduce the background of the ferroelectric nematic phase before then showing the molecular structures of a range of materials which exhibit the phase, describing their structure-property relationships and therefore giving an up-to-date account of the literature for this fascinating new mesophase.
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Affiliation(s)
- Ewan Cruickshank
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
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Katariya KD, Nakum KJ, Soni H, Nada S, Hagar M. Imine Based Four-Ring Chalcone-Ester Liquid Crystals: Synthesis, Characterization, Mesomorphic Behaviour and DFT approach. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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Strachan GJ, Majewska MM, Pociecha D, Storey JMD, Imrie CT. Using Lateral Substitution to Control Conformational Preference and Phase Behaviour of Benzanilide-based Liquid Crystal Dimers. Chemphyschem 2022; 24:e202200758. [PMID: 36449329 DOI: 10.1002/cphc.202200758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/09/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
The inclusion of secondary and tertiary benzanilide-based mesogenic groups into liquid crystal dimers is reported as a means to develop new materials. Furthermore, substitution at the nitrogen atom is shown to introduce an additional synthetic 'handle' to modify the molecular structure of the tertiary materials. The design of these materials has proved challenging due to the strong preferences of 3° benzanilides for the E amide conformation. In this work, lateral substitution is used to modify the conformational preferences of the amide linkage and promote liquid crystallinity for a series of N-methyl benzanilide dimers. As the proportion of the E conformer decreases, the nematic-isotropic transition temperatures increase, and enantiotropic nematic behaviour is observed. We also report the synthesis and characterisation of the analogous 2° benzanilide-based materials, which show nematic and twist-bend nematic behaviour. This approach highlights the effects that seemingly small structural modifications, such as the inclusion and position of a methyl group, can have on molecular shape and hence, liquid crystalline behaviour.
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Affiliation(s)
- Grant J Strachan
- Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK.,Current address: School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Magdalena M Majewska
- Faculty of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Damian Pociecha
- Faculty of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - John M D Storey
- Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK
| | - Corrie T Imrie
- Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK
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Huang H, Cong Y, Du A, Hu B, Li J, Zhang B. Liquid crystalline dimers containing a cholesteryl group: Chiral smectic phases, and re-entrant TGBA* phase. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117920] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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