| 초록 |
Discotic liquid crystal (DLC) materials have been attracting increasing attention due to their particular transport properties related to electron and hole transfer, energy migration, etc. Such DLC molecules have been known to form both nematic and columnar mesophases. The hydrogen bonding is one of the powerful tools for assembling molecules and building organized molecular structures. The objective of this study is to synthesize and characterize a new type of hydrogen-bonded DLCs based on the self-assembly of stilbazole derivatives around a phloroglucinol (PG) core. 1,3,5-Trihydroxybenzene(phloroglucinol) was used as the core molecules. Alkoxystilbazoles (ASn), cyanoalkoxystilbazoles (CASn) and alkoxybenzoyloxystilbazoles (ABSn) were synthesized for the peripheral units. The formation of complexes and the thermal stability of hydrogen bonding were studied by temperature-dependent FT-IR spectroscopy. The mesomorphic properties of DLC complexes were investigated by DSC, POM and X-ray diffraction. The intermolecular hydrogen bonding was stable in the liquid crystalline phase but decomposed suddenly at clearing point. By combining the results obtained by DSC, POM and XRD measurements, the formation of ordered columnar mesophase was dependent on the alkyl chain length around the core group. The structural variations such as alkyl chain length, polar substituent and extended mesogen resulted in the formation of hydrogen-bonded DLCs with a variety in liquid crystalline properties. |
