Steric Interaction between Flexible Main Chain and Nonmesogenic Cyclic Pendants Leading to Thermotropic Liquid Crystalline Property

2010 ◽  
Vol 43 (21) ◽  
pp. 8942-8949 ◽  
Author(s):  
Xue Mei ◽  
Yang Chu ◽  
Jiaxi Cui ◽  
Zhihao Shen ◽  
Xinhua Wan
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Steric Interaction ◽  
Crystalline Property ◽  
Liquid Crystalline Property

Synthesis and Liquid Crystalline Properties of Low Molecular Weight Bis-Chalcone Compounds

2021 ◽  
Vol 18 ◽  
Author(s):  
Anju K Sasidharan ◽  
Jomon Mathew ◽  
Ammathnadu S. Achalkumar ◽  
Manoj Mathews
Keyword(s):  
Molecular Weight ◽  
Liquid Crystalline ◽  
Low Molecular Weight ◽  
Aliphatic Chain ◽  
Aromatic Rings ◽  
Property Relationship ◽  
Crystalline Property ◽  
Liquid Crystalline Property ◽  
Mesomorphic Properties ◽  
Structure Liquid

Aim: In this paper, we report on the synthesis and liquid crystalline properties of some low molecular weight bis-chalcone compounds derived from acetone, cyclopentanone and cyclohexanone mesogenic cores. Background: Structurally bis-chalcones belong to a broader family of chalcone compounds. Chalcone is a compound that consists of two aromatic rings linked by an unsaturated objective. Liquid crystalline chalcones are prepared by aliphatic chain substituents on two aromatic rings. Chalcones are well studied for their mesomorphic properties. Compared to a large number of chalcone based LCs reported, only a few articles have been published on the mesomorphic properties of bis-chalcone compounds. The target compounds of the present study varied not only in their central core but also in number and position of terminal aliphatic chain substitutiona key structural unit in deciding the liquid crystalline properties of a compound. Method: All target compounds were synthesized in good yield by base catalyzed Claisen-Schmidt condensation reaction. Molecular structures were confirmed by FT-IR, 1H NMR, 13C NMR, and mass spectroscopic methods. Liquid crystalline property of these compounds was evaluated using polarizing optical microscopy and differential scanning calorimetry. Results: Although none of the acetone based compounds exhibited mesomorphism, cyclopentanone and cyclohexanone based compounds with octyloxy chain at para position on either side of the dibenzylidine ring stabilized liquid crystalline smectic (SmA and SmC) and nematic (N) phases. The observed structure-liquid crystalline property relationship was explained by structural analysis of molecules using DFT calculations. Considering the inherent photoluminescence nature of the chalcone moiety, a preliminary study was carried out on a selected compound to reveal its fluorescence property. Conclusion: Our study brings about an important structure-liquid crystalline property relationship in a relatively unexplored class of bis-chalcone liquid crystals.

scholarly journals Functional poly(phenylacetylene)s carrying azobenzene pendants: Polymer synthesis, photoisomerization behaviors, and liquid-crystalline property

Polymer ◽  
2011 ◽  
Vol 52 (23) ◽  
pp. 5290-5301 ◽  
Author(s):  
Xiao A.-Zhang ◽  
Hui Zhao ◽  
Yuan Gao ◽  
Jiaqi Tong ◽  
Liang Shan ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Polymer Synthesis ◽  
Crystalline Property ◽  
Liquid Crystalline Property

A Novel Anisotropic Electroactive Liquid Crystalline Polyimide Containing Aniline Trimer Segments

2011 ◽  
Vol 239-242 ◽  
pp. 1269-1274
Author(s):  
Si Wei Liu ◽  
Qiao Ying Cao ◽  
Yi Zhang ◽  
Zhen Guo Chi ◽  
Jia Rui Xu
Keyword(s):  
Molecular Weight ◽  
Liquid Crystalline ◽  
Sulfonyl Chloride ◽  
Dimethyl Formamide ◽  
Hydroxybenzoic Acid ◽  
Shear Direction ◽  
Crystalline Property ◽  
Liquid Crystalline Property

A novel type of liquid crystalline polyimide with good electroactive properties has been successfully synthesized through polycondensation in the component solvent of benzene sulfonyl chloride, dimethyl formamide and pyridine byN,N’-hexane-1,6-diylbis(trimellitimides),p-hydroxybenzoic acid, 4,4'-dihydroxybenzophenone and double amino-capped aniline trimer (N1,N1'-(1,4-phenylene)bis(benzene-1,4-diamine)). The structure of the obtained polymer was characterized and verified. The polymer can be dissolved in the component solvent of phenol and chloroform or DMF, NMP alone,et al. The molecular weight (Mn=1.7×104,Mw=8.2×104，PDI=4.8) was determined by gel permeantion chromatography using DMF as eluent. By combining the excellent properties of both polyimide and oligoaniline, such material could be used in more broad fields. Furthermore, due to the orientation properties of liquid crystalline property, the conductivity of this polymer is anisotropic, with 10-6S/cm along the shear directionvs.10-7S/cm perpendicular to the shear direction.

scholarly journals Novel banana-discotic hybrid architectures

2009 ◽  
Vol 5 ◽  
Author(s):  
Hari Krishna Bisoyi ◽  
H T Srinivasa ◽  
Sandeep Kumar
Keyword(s):  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Elemental Analysis ◽  
Liquid Crystalline ◽  
Scanning Calorimetry ◽  
Spectral Techniques ◽  
Design And Synthesis ◽  
Chemical Structures ◽  
Crystalline Property ◽  
Liquid Crystalline Property

Here we present the design and synthesis of novel banana-discotic dimers and banana-bridged discotic dimers. The chemical structures have been characterized by spectral techniques and elemental analysis. The thermal behaviors of the compounds have been investigated by polarizing optical microscopy and differential scanning calorimetry. None of these synthesized compounds exhibit any liquid crystalline property probably because of the incompatibility of the bent-core with the discotic core.

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