화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.452, 63-72, 2006
Nematic and smectic a phases in ortho-hydroxy-para-hexadecanoyloxbenzylidene-para-substituted anilines
Four Schiff base esters containing the different substituents of R=CN, OH, SH, and NO2 were synthesized, and the physical characterization was carried out along with spectroscopic techniques (FT-IR and NMR). Thermal properties were analyzed by using differential scanning calometry (DSC), and their liquid crystal textures were observed under polarized optical microscope. All compounds thus obtained exhibit mesomorphic properties of which the alignment of molecules are inclined to either nematic, N (R=SH), or smectic, SmA (for R=CN, OH, and NO2 ). The unidentifiable subphases in crystal region were recorded in all compounds except that with R=OH. The presence of a lateral hydroxyl group has been claimed to contribute to the enhanced molecular ordering, leading to a higher clearing temperature.