Molecular flexibility dependence mesomorphism |
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Authors: | Vinay S Sharma |
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Institution: | Chemistry Department, K. K. Shah Jarodwala Maninagar Science College, Gujarat University, Ahmedabad, Gujarat, India |
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Abstract: | A novel series of chalconyl homologue derivatives with RO.C6H4.COO.C6H4.CO.CH:CH-C6H4.N.(CH3)2 (Para) have been synthesized and thermotropically studied with a view to understanding and establishing the effect of molecular structure on mesomorphic behavior of the novel homologues. The series consists of thirteen homologues (C1 to C18). C7 to C18 homologues are smectogenic, C4 to C18 nematogenic and C1 to C3 nonmesomorphic. Thus, novel chalconyl series is predominantly nematogenic and partly smectogenic. Transition temperatures and textures of mesophases were determined using an polarizing optical microscope (POM) equipped with a heating stage. Analytical and spectral data confirmed molecular structures of homologues. Phase transition curves showing phase behavior in a phase diagram behaved in normal manner. Thermal stability for smectic and nematic are relatively low at 59.6 °C and 76.6 °C respectively whose, smectogenic and nematogenic phase length vary from 12 to 16 °C and 06 to 20 °C, respectively. Mesomorphic behaviors of the present series are compared with a structurally similar known homologous series. |
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Keywords: | Mesomorphism smectic nematic monotropic thermotropic |
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