Induction of Higher Intermolecular Packing by Introduction of Fluoro Groups onto Discotic Nematogens.

• Main Authors: Shu-Wei Tsao, 曹書瑋
• Other Authors: Hsiu-Fu Hsu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/77759070135652763595

碩士 === 淡江大學 === 化學學系碩士班 === 97 === In this study, fluorine atoms behave high electronegtivity were induced on to rod-like shape structure of diynyl benzene derivatives and disc-like shape structure of hexaynyl benzene derivatives, respectively. Owing to dipole moments arise from fluorine atoms manipulating the stacking interactions between disks and thus lowering the transition temperatures and those two shape of molecules have the ability of self-assembling to form high ordered columnar liquid crystals. It is worthy noting that rod-like and disc-like shape of structure containing fluorine atoms have lower transition temperatures than those don’t contain fluorine atoms. Futhermore the disc-like ones exhibit wider liquid crystal temperature ranges. Single X-ray diffraction results indicate that fluorine atoms in disc-like ones form hydrogen bonding with adjacent hydrogen atoms. Hydrogen bonding stabilize those mesophases and the arrangement of columnar phase. Thus lowering transition temperature and wider mesogenic temperature ranges.