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Alamro FS, Ahmed HA, El-Atawy MA, Khushaim MS, Bedowr NS, AL-Faze R, Al-Kadhi NS. Physical and Thermal Characterizations of Newly Synthesized Liquid Crystals Based on Benzotrifluoride Moiety. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4304. [PMID: 37374488 PMCID: PMC10304381 DOI: 10.3390/ma16124304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 05/29/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
The mesomorphic stability and optical activity of new group-based benzotrifluoride liquid crystals, (E)-4-(((4-(trifluoromethyl) phenyl) imino) methyl) phenyl 4-(alkyloxy)benzoate, or In, were investigated. The end of the molecules connected to the benzotrifluoride moiety and the end of the phenylazo benzoate moiety have terminal alkoxy groups which can range in chain length from 6 to 12 carbons. The synthesized compounds' molecular structures were verified using FT-IR, 1H NMR, mass spectroscopy, and elemental analysis. Mesomorphic characteristics were verified using differential scanning calorimetry (DSC) and a polarized optical microscope (POM). All of the homologous series that have been developed display great thermal stability across a broad temperature range. Density functional theory (DFT) determined the examined compounds' geometrical and thermal properties. The findings showed that every compound is entirely planar. Additionally, by using the DFT approach, it was possible to link the experimentally found values of the investigated compounds' investigated compounds' mesophase thermal stability, mesophase temperature ranges, and mesophase type to the predicted quantum chemical parameters.
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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; (F.S.A.); (N.S.A.-K.)
| | - Hoda A. Ahmed
- Department of Chemistry, Faculty of Science, Cairo University, Cairo 12613, Egypt
| | - Mohamed A. El-Atawy
- Chemistry Department, Faculty of Science, Alexandria University, Ibrahemia, P.O. Box 426, Alexandria 21321, Egypt
- Chemistry Department, Faculty of Science, Taibah University, Yanbu 46423, Saudi Arabia;
| | - Muna S. Khushaim
- Department of Physics, Faculty of Science, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia;
- Strategic Research Labs, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia
| | - Noha S. Bedowr
- Chemistry Department, Faculty of Science, Taibah University, Yanbu 46423, Saudi Arabia;
| | - Rawan AL-Faze
- Department of Chemistry, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah 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; (F.S.A.); (N.S.A.-K.)
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Han ZY, Kun SQ, Kang JT, Jia YG. New (-)-menthol-based blue phase liquid crystals with different polar substituents in the terminal group: Synthesis, mesophase behaviors, and DFT calculations. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jamain Z, Khairuddean M, Guan-Seng T, Rahman ABA. Synthesis, Characterisation and Mesophase Transition of Hexasubstituted Cyclotriphosphazene Molecules with Schiff Base and Azo Linking Units and Determination of Their Fire Retardant Properties. Macromol Res 2021. [DOI: 10.1007/s13233-021-9013-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jamain Z, Khairuddean M, Guan-Seng T. Synthesis of novel liquid crystalline and fire retardant molecules based on six-armed cyclotriphosphazene core containing Schiff base and amide linking units. RSC Adv 2020; 10:28918-28934. [PMID: 35520049 PMCID: PMC9055837 DOI: 10.1039/d0ra03812a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
Nucleophilic substitution reaction between 4-hydroxybenzaldehyde and hexachlorocyclotriphosphazene, HCCP formed hexakis(4-formlyphenoxy)cyclotriphosphazene, 1. Intermediates 2a-e was formed from the alkylation reaction of methyl 4-hydroxybenzoate with alkyl bromide which further reduced to form benzoic acid intermediates. Further reaction of 2a-e and other substituted benzoic acid formed 3a-h, which then reduced to give subsequent amines, 4a-h. Other similar reaction was used to synthesis 4i. Condensation reaction between 1 and 4a-i yielded hexasubstituted cyclotriphosphazene compounds, 5a-i having Schiff base and amide linking units, and these compounds consist of different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, carboxy, chloro, and nitro groups, respectively. Compound 5j with amino substituent at terminal end was formed from the reduction of 5i. All the intermediates and compounds were characterized using Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and CHN elemental analysis. Mesophase texture of these compounds were determined using Polarized Optical Microscope (POM) and their mesophase transition were further confirmed using Differential Scanning Calorimetry (DSC). Only compounds 5a-e with alkoxy chains exhibited smectic A phase while other intermediates (1, 2a-e, 3a-h, and 4a-i) and final compounds (5f-j) are found to be non-mesogenic with no liquid crystal behaviour. The confirmation of the identity of the SmA phase was determined using XRD analysis. The study on the structure-properties relationship was conducted in order to determine the effect of the terminal group, length of the chains and linking units to the mesophase behaviour of the compounds. Moreover, the fire retardant properties of these compounds were determined using Limiting Oxygen Index (LOI) testing. Polyester resin with LOI value of 22.53% was used as matrix for moulding in the study. The LOI value increased to 24.71% when this polyester resin incorporated with 1 wt% of HCCP. Generally, all the final compounds showed a positive results with LOI value above 27% and the highest LOI value was belonged to compound 5i with 28.53%. The high thermal stability of the Schiff base molecules and the electron withdrawing group of the amide bonds and nitro group enhanced the fire retardant properties of this compound.
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Affiliation(s)
- Zuhair Jamain
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah (UMS) 88400 Kota Kinabalu Sabah Malaysia
- School of Chemical Sciences, Universiti Sains Malaysia (USM) 11800 Penang Malaysia
| | - Melati Khairuddean
- School of Chemical Sciences, Universiti Sains Malaysia (USM) 11800 Penang Malaysia
| | - Tay Guan-Seng
- School of Industrial Technology, Universiti Sains Malaysia (USM) 11800 Penang Malaysia
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Jamain Z, Khairuddean M, Guan-Seng T. Synthesis of New Star-Shaped Liquid Crystalline Cyclotriphosphazene Derivatives with Fire Retardancy Bearing Amide-Azo and Azo-Azo Linking Units. Int J Mol Sci 2020; 21:ijms21124267. [PMID: 32560033 PMCID: PMC7352503 DOI: 10.3390/ijms21124267] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 11/16/2022] Open
Abstract
Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of linking units in the molecules such as amide-azo (6a-j) and azo-azo (8a-j). The homologues of the same series contain different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxyl, carboxyl, chloro, nitro, and amino groups. All the intermediates and final compounds were characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and Carbon, Hydrogen, and Nitrogen (CHN) elemental analysis. Liquid crystal properties for all compounds were determined using polarized optical microscope (POM). It was found that only intermediates 2a-e with nitro and alkoxyl terminal chains showed a smectic A phase. All the final compounds with alkoxyl substituents are mesogenic with either smectic A or C phases. However, other intermediates and compounds were found to be non-mesogenic. The study on the fire retardancy of final compounds was determined using limiting oxygen index (LOI) method. The LOI value of pure polyester resin (22.53%) was increased up to 24.71% after treating with 1 wt% of hexachlorocyclotriphosphazene (HCCP). Moreover, all the compounds gave positive results on the LOI values and compound 6i with the nitro terminal substituent showed the highest LOI value of 27.54%.
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Affiliation(s)
- Zuhair Jamain
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah (UMS), Kota Kinabalu 88400, Malaysia
- School of Chemical Sciences, Universiti Sains Malaysia (USM), Penang 11800, Malaysia
- Correspondence: (Z.J.); (M.K.)
| | - Melati Khairuddean
- School of Chemical Sciences, Universiti Sains Malaysia (USM), Penang 11800, Malaysia
- Correspondence: (Z.J.); (M.K.)
| | - Tay Guan-Seng
- School of Industrial Technology, Universiti Sains Malaysia (USM), Penang 11800, Malaysia;
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Liquid-Crystal and Fire-Retardant Properties of New Hexasubstituted Cyclotriphosphazene Compounds with Two Schiff Base Linking Units. Molecules 2020; 25:molecules25092122. [PMID: 32370000 PMCID: PMC7248761 DOI: 10.3390/molecules25092122] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 04/19/2020] [Accepted: 04/22/2020] [Indexed: 12/27/2022] Open
Abstract
A series of new hexasubstituted cyclotriphosphazene compounds (4a–j) consisting of two Schiff base linking units and different terminal substituents was successfully synthesized and characterized. The structures of these compounds were confirmed using Fourier Transform Infra-Red (FTIR), Nuclear Magnetic Resonance (NMR), and CHN elemental analysis. Polarized optical microscopy (POM) was used to determine their liquid-crystal behavior, which was then further confirmed using differential scanning calorimetry (DSC). Compounds 4a–i with heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, 4-carboxyphenyl, chloro, and nitro terminal ends, respectively, showed the liquid-crystal properties, whereas compound 4j with the amino group was found to be non-mesogenic. The attachment of an electron-donating group in 4j eventually give a non-mesogenic product. The study of the fire-retardant properties of these compounds was done using the limiting oxygen index (LOI). In this study, polyester resin (PE) was used as a matrix for moulding, and the LOI value of pure PE was 22.53%. The LOI value increased to 24.71% when PE was incorporated with 1 wt.% of hexachlorocyclotriphosphazene (HCCP), thus indicating that HCCP has a good fire-retardant properties. The result showed that all the compounds have good agreement in their LOI values. Compound 4i with a nitro terminal group gave the highest LOI value of 28.37%.
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Nafee SS, Hagar M, Ahmed HA, Alhaddad O, El-Shishtawy RM, Raffah BM. New two rings Schiff base liquid crystals; ball mill synthesis, mesomorphic, Hammett and DFT studies. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112161] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Pai P, Kulkarni SD, Srinivasulu M, Baral M, Apoorva M, Bhagavath P. Enhanced conductivity in nanoparticle doped hydrogen bonded binary mixture. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111754] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Alnoman R, Al-Nazawi FK, Ahmed HA, Hagar M. Synthesis, Optical, and Geometrical Approaches of New Natural Fatty Acids' Esters/Schiff Base Liquid Crystals. Molecules 2019; 24:E4293. [PMID: 31775342 PMCID: PMC6930458 DOI: 10.3390/molecules24234293] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 11/20/2022] Open
Abstract
Schiff base liquid crystals, known as [4-(hexyloxy)phenylimino)methyl]phenyl palmitate (IA), [4-(hexyloxy)phenylimino)methyl]phenyl oleate (IIA) and [4-(hexyloxy)phenylimino)methyl]phenyl linoleate (IIIA), were synthesized from palmitic, oleic, and linoleic natural fatty acids. The prepared compounds have been investigated for their thermal and optical behavior as well as phase formation using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Molecular structures of all studied compounds were confirmed via elemental analysis, FT-IR, 1H NMR, and 13C NMR. Smectic phase is the observed mesophase for all compounds; however, their type and range depend upon the terminal alkanoate chains attached to the phenyl ring. Computational calculations, Density functional theory (DFT), energy difference of the frontier molecular orbital (FMOs), as well as the thermodynamic parameters of different molecular configurations isomers were discussed. It was found that the mesophase behavior and the geometrical characteristics were affected by the degree of unsaturation of fatty terminal chains. Furthermore, the geometrical structure of the CH=N linkage plays an important role in the thermal stability and optical transition temperature.
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Affiliation(s)
- Rua Alnoman
- College of Sciences, Chemistry Department, Taibah University, Yanbu 30799, Saudi Arabia;
| | | | - Hoda A. Ahmed
- College of Sciences, Chemistry Department, Taibah University, Yanbu 30799, Saudi Arabia;
- Faculty of Science, Department of Chemistry, Cairo University, Cairo 12613, Egypt
| | - Mohamed Hagar
- College of Sciences, Chemistry Department, Taibah University, Yanbu 30799, Saudi Arabia;
- Faculty of Science, Chemistry Department, Alexandria University, Alexandria 21321, Egypt
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Synthesis and mesophase behaviour of Schiff base/ester 4-(arylideneamino)phenyl-4″-alkoxy benzoates and their binary mixtures. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.10.035] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Jaworska J, Korbecka I, Kochel A, Galewski Z. 4-(4′-Alkyloxyphenylazo)benzoyl chlorides not only intermediates but photosensitive mesogens for optical switching. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Iwan A. Thermotropic and opto(electrical) properties of liquid crystalline imine with two fluorinated chains. J Mol Liq 2010. [DOI: 10.1016/j.molliq.2010.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Godzwon J, Sienkowska MJ, Galewski Z. Smectic polymorphism of 4-nonyloxybenzylidene-4′-alkyloxyanilines. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2007.04.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Paja̧k J, Rospenk M, Galewski Z, Sobczyk L. 4-Chloro-2′-hydroxy-4′-alkoxyazobenzenes. Intramolecular OH··N hydrogen bonding and liquid crystalline properties. J Mol Liq 2003. [DOI: 10.1016/s0167-7322(03)00011-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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