Synthesis and characterization of new ferroelectric liquid crystals containing a phenyl biphenyl carboxylate mesogenic group and oligooxyethylene spacers

Hsiue, Ging‐Ho; Wu, Jung-Lung; Chen, Jr-Hong

doi:10.1080/02678299608032854

Cited by 11 publications

(3 citation statements)

References 17 publications

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“…The XRD pattern showed three orders of reflection in the small angle region that are assigned 001, 002, and 003 and the wide angle region showed multiple reflections with varying intensity (Figure S5D of the Supporting Information). The phase has been assigned as Crystal E (Figure S2J of the Supporting Information) by considering the wide angle pattern of XRD. ,− In the case of the ODPTC homologue, when the smectic B phase was cooled, crystallization is observed with an enthalpy value of 7.68 kcal/mol (Table ). Thus, it is concluded on the basis of the HOPM, DSC, and XRD studies that the HDPTC and ODPTC homologues exhibit enantiotropic smectic C and smectic B phases.…”

Section: Resultsmentioning

confidence: 99%

¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

2015

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Three-ring mesogens with a core comprising thiophene linked to one phenyl ring directly and to the other via flexible ester are synthesized with terminal alkoxy chains to probe the mesophase properties and find the molecular order. The phenyl thiophene link in the core offers a comparison of the mesophase features with the molecular shape of the mesogen. The synthesized mesogens display enantiotropic polymesomorphism and accordingly nematic, smectic A, smectic C and smectic B mesophases are perceived depending upon the terminal chain length. For some of the homologues, monotropic higher order smectic phases such as smectic F and crystal E are also witnessed. The existence of polymesomorphism are originally observed by HOPM and DSC and further confirmed by powder X-ray diffraction studies. For the C8 homologue, high resolution solid state (13)C NMR spectroscopy is employed to find the molecular structure in the liquid crystalline phase and using the 2D SLF technique, the (13)C-(1)H dipolar couplings are extracted to calculate the order parameter. By comparing the ratio of local order of thiophene as well as phenyl rings, we establish the bent-core shape of the mesogen. Importantly, for assigning the carbon chemical shifts of the core unit of aligned C8 mesogen, the (13)C NMR measured in mesophase of the synthetic intermediate is employed. Thus, the proposed approach addresses the key step in the spectral assignment of target mesogens with the use of (13)C NMR data of mesomorphic intermediate.

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Section: Resultsmentioning

confidence: 99%

¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

2015

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“…In all these investigations, the chains introduced into the mesogen structure were always alkyl or alkoxy ones. Nevertheless, among the flexible substituents which can be used to promote the liquid crystal properties, polyoxyethylene ether (POE) may be of interest [23][24][25]. Long polyoxyethylene ether chains will enforce lyotropic liquid crystals, but short chains will lead to nematic liquid crystals.…”

Section: Introductionmentioning

confidence: 99%

Gas chromatographic properties of some liquid crystals containing dioxyethylene ether terminal chains

Ammar-Khodja

Guermouche

et al. 1999

Chromatographia

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“…The poly(oxyethylene) chain is another example of an incompatible segment applied as the flexible part of liquid crystalline structures, differing in chemical properties from the poly(methylene) substituent. − According to literature reports, it destabilizes liquid crystalline phases in some cases but promotes in others . Poly(oxyethylene) substituents are useful as headgroups in nonionic surfactants with the interesting feature of complexing alkali metal cations; these complexes are thermotropic liquid crystalline polyelectrolytes.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Flexible Segments on Liquid Crystalline Properties in Terms of Solubility Parameters. An Attempt at Quantitative Interpretation

Białecka‐Florjańczyk

2006

J. Phys. Chem. B

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The phase behavior of some rodlike block molecules has been reviewed with reference to the polarity of constituent segments. It was found that the ability of the mesophase formation is connected with differences in polar character between the flexible chains and rigid cores. Thus the polar poly(oxyethylene) group connected with the polar rigid core reduces mesophase stability but is advantageous when put together with some apolar building blocks. An attempt at quantitative estimation of the incompatibilities of different parts of molecules by means of Hansen solubility parameters delta and Flory interaction parameters chi has also been made. On the basis of chi parameters the Gibbs free energies of mixing of these segments were calculated. The changes of Gibbs free energy reflecting the compatibility of segments and their tendency to the phase separation and the volume fraction of mesogenic rigid core reflecting their ability to arrangement in one direction appear to be crucial in terms of type of the mesophase formation.

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Synthesis and characterization of new ferroelectric liquid crystals containing a phenyl biphenyl carboxylate mesogenic group and oligooxyethylene spacers

Cited by 11 publications

References 17 publications

¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

Gas chromatographic properties of some liquid crystals containing dioxyethylene ether terminal chains

The Influence of Flexible Segments on Liquid Crystalline Properties in Terms of Solubility Parameters. An Attempt at Quantitative Interpretation

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Synthesis and characterization of new ferroelectric liquid crystals containing a phenyl biphenyl carboxylate mesogenic group and oligooxyethylene spacers

Cited by 11 publications

References 17 publications

13C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

13C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

Gas chromatographic properties of some liquid crystals containing dioxyethylene ether terminal chains

The Influence of Flexible Segments on Liquid Crystalline Properties in Terms of Solubility Parameters. An Attempt at Quantitative Interpretation

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Product

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¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens

¹³C NMR Studies, Molecular Order, and Mesophase Properties of Thiophene Mesogens