| Summary: | 碩士 === 國立臺灣師範大學 === 化學研究所 === 91 === Abstract
The synthesis、characterization, and mesomorphic properties of a new class of heteronuclear compounds derivative from 2, 4, 6-triphenyl-1, 3, 5-triazine was as a core group, The compounds were prepared by condensation reaction of benzonitrile in the presence of chlorosulfonic acid。
Two types of liquid crystalline molecules were investigated:
(1) The number of flexible side chains were connected to a 1, 3, 5-triazine ring, each of R group, which used the alkoxy side chains、or different side chains of ether and bulkyl of the alkoxy. However, all these compounds with different side chains showed no mesophases, only crystal to liquid transition.
(2) Conversely, the second molecule was benzoate attached between a rigid core group and alkoxy or alkyl side chains. The side chain length was made of 1, 3, 5-triazine ring derivatives that had been six side chains and peripheral pentyl to octyl group tails have liquid crystal properties, respectively. In this work a series of structurally similar compounds in which the carbon on the side chain are replaced by oxygen atom were prepared, and their mesomorphic properties were studied. These compounds with pentyloxy to heptyloxy flexible side chains exhibited ND phase。
The liquid crystalline behaviour of these compounds with benzoate attached to a 1, 3, 5-triazine ring derivative were studied by thermal analysis (DSC), polarizing optical microscopy (POM) and powder X-ray
diffraction (XRD).
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