Synthesis, Characterization And Mesomorphic Properties of Side Chain Liquid Crystalline Oligomer Having Schiff Base Type Mesogenic Group

Gülbaş, Hülya Elmali; Coskun, Demet; Gürsel, Yeşim Hepuzer; Bilgin‐Eran, Belkız

doi:10.5185/amlett.2014.amwc.1022

Cited by 13 publications

(11 citation statements)

References 13 publications

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“…The electron-donating compound, A , the CH(CH 3 ) 2 substituent, exhibits an SmA phase with a thermal stability range of 24.1 °C, while the unsubstituted derivative B has a smectic phase with a range of 20.1 °C and a low melting temperature of 67.3 °C. It was reported in [13] that the dipole moment of the mesomeric portion of the molecule impacts the type and stability of the mesophase produced, which is dependent on the attached terminal polar substituent and the steric one that varies according to size. The halogen substituent at the terminal position showed strong influence on the mesomorphic behavior of the Schiff base molecules [30].…”

Section: Resultsmentioning

confidence: 99%

“…Several Schiff base mesogenic homologous series of a low molar mass and twist-bend nematic phase have been investigated [10,11,12]. Many of these studies have reported to show the effect of the terminal substituent with either alkoxy chains or polar compact substituents [13]. The proper selection of a mesogenic moiety, terminal groups, and flexible wings are the essential criteria for designing new thermotropic liquid crystal materials with new phase transitions [14].…”

Section: Introductionmentioning

confidence: 99%

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The Synthesis of New Thermal Stable Schiff Base/Ester Liquid Crystals: A Computational, Mesomorphic, and Optical Study

et al. 2019

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A Schiff base supramolecular 4-[(4-(hexyloxy)phenylimino)methyl]benzoic acid and a new series of Schiff base/ester linkages named 4-substitutedphenyl 4-[(4-(hexyloxy)phenylimino)methyl]benzoate liquid crystals were synthesized. The thermal stability, mesomorphic, and optical behavior of the prepared compounds were characterized by differential scanning calorimetry (DSC), Thermogravemetric analysis (TGA), polarized optical microscopy (POM), and UV spectroscopy. FT-IR, 1H-NMR, 13C-NMR, and elemental analyses were carried out to elucidate and confirm the molecular structures of the synthesized compounds. The investigated series comprising different sized terminal polar groups changed between CH(CH3)2, H, I, and F. It was found that the supramolecular imino acid dimer is enantiotropic dimorphic, with a wide SmA phase and a good N phase range. The other series of terminally substituted Schiff base/esters are mesomorphic with a high thermal stable SmA phase, except the iodo derivative, which showed dimorphic SmA and N phases. The effect of the position and the orientation of the cores, as well as the terminal substituent of the type and the stability of the mesophase, were studied. A computational theoretical study of the effects of the van der Waal’s volume, the Hammett substituent coefficient, the inductive sigma constant, and other geometrical parameters were discussed. The study revealed that the planarity of the two phenyl rings attached with an imino linking group impacted the resonance effect of the terminal substituents rather than their inductive effect. A detailed study on the effect of the estimated thermal parameters, as well as their geometrical planarity with the type and stability of the formed mesophase, was discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Synthesis of New Thermal Stable Schiff Base/Ester Liquid Crystals: A Computational, Mesomorphic, and Optical Study

et al. 2019

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“…For example, LCPs with side salicylaldimine fragments were prepared by free‐radical polymerization of the corresponding monomers 5‐(10‐undecenyloxy)‐2‐[[(4‐(hexyloxy) phenyl) imino] methyl] phenol and 5‐(10‐undecenyloxy)‐2‐[[(4‐(hexyl) phenyl) imino] methyl] phenol . Modified polyguanidines, characterized by liquid crystal properties (chirality, homogeneity of the length of side chains, binding of mesogens with side chains) are of interest …”

Section: Liquid Crystal Chelating Polymersmentioning

confidence: 99%

Synthetic Methodologies for Chelating Polymer Ligands: Recent Advances and Future Development

Джардималиева

Uflyand

2018

ChemistrySelect

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This review summarizes recent progress in synthetic methodologies of chelating polymer ligands such as linear, branched, cross‐linked, grafted polymers, polymer films, liquid crystal polymers, dendrimers, star‐shaped and hyperbranched polymers. The features of methods for producing chelating polymer ligands are considered in detail: free‐radical (co)polymerization, living/controlled radical, metathesis, grafted, chemical oxidized, microwave‐assisted and asymmetric polymerization, electropolymerization, cyclopolymerization, polycondensation, post‐polymerization modification, click chemistry methods and “green” synthesis. The main directions of the development of synthetic chemistry of chelating polymeric ligands are analyzed. The bibliography includes works published in the last five years.

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“…These modifications in the properties of the LCs may be beneficial for mesomorphism as well as the physical properties necessary for technical uses. Schiff base linkages have been broadly employed in the preparation of numerous LC derivatives [ 14 , 15 , 16 , 17 ]. Most reports are focused on Schiff bases since the discovery of nematogenic 4-methoxybenzylidene-4′-butylaniline at room temperature [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

et al. 2021

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Homolog series based on three aromatic rings bearing terminal alkoxy chain of various lengths named 4-(4-(alkoxy)phenylimino)methyl)phenyl nicotinate (An) were synthesized. The alkoxy-chain length changed between 6, 8 and 16 carbons. Mesomorphic and optical properties were carried out via differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Elemental analyses, FT-IR and NMR spectroscopy were carried out to elucidate the molecular structures of the prepared derivatives. Mesomorphic results indicated that all the synthesized homologs (An) are monomorphic possessing the nematic (N) phase enantiotropically with wide thermal stability. Computational simulations were measured via density functional theory (DFT) theoretical calculation tool. The estimated thermal and geometrical parameters are in agreement with the experimental data. By discussing the estimated parameters, it was found that the molecular architecture, dipole moment and the polarizability of the investigated compounds are highly affected by the length of the attached terminal flexible chain and the location of the nitrogen atom in the other terminal aromatic ring. Binary phase diagrams of two corresponding homologs with different proportionating terminals were constructed, and their binary phase physical properties were discussed in terms of the temperature range and stability of the N phase.

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Synthesis, Characterization And Mesomorphic Properties of Side Chain Liquid Crystalline Oligomer Having Schiff Base Type Mesogenic Group

Cited by 13 publications

References 13 publications

The Synthesis of New Thermal Stable Schiff Base/Ester Liquid Crystals: A Computational, Mesomorphic, and Optical Study

The Synthesis of New Thermal Stable Schiff Base/Ester Liquid Crystals: A Computational, Mesomorphic, and Optical Study

Synthetic Methodologies for Chelating Polymer Ligands: Recent Advances and Future Development

Synthesis, Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

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