Azo substituted V-shaped liquid crystalline compounds: synthesis and mesophase characterisation |
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Authors: | N.G. Nagaveni |
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Affiliation: | Centre for Soft Matter Research , P.O. Box No. 1329, Jalahalli, Bangalore 560 013 , Karnataka , India |
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Abstract: | The first examples of V-shaped liquid crystalline materials made of non-symmetrical molecules are reported. They belong to a homologous series of azo substituted compounds, wherein the two arms attached to the 1,2-positions of the benzene ring are different. The new compounds are characterised by the spectroscopic methods. The liquid crystalline properties are investigated using polarising optical microscopy, differential scanning calorimetry and X-ray diffraction studies. All the compounds synthesised here are found to be liquid crystalline. They exhibit nematic and smectic A mesophases, which are uniaxial in nature. The preliminary qualitative experiments showed that the compounds are photosensitive. Based on the X-ray results, the molecular arrangement of these compounds in their mesophases is illustrated. A relationship between molecular structures to mesomorphic properties in such systems has also been predicted. |
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Keywords: | azo compound liquid crystal photosensitive V-shape X-ray nematic smectic |
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