Synthesis and mesogenic properties of novel ferroelectric liquids crystals derived from (R)-(-)-mandelic acid and its analogue

• Main Authors: Chen Huang Jhang, 陳皇璋
• Other Authors: 蔡文亮
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/22082140953276460041

碩士 === 國立高雄師範大學 === 化學系 === 94 === Abstract Derivatives of chiral acids such as (R)-(-)-mandelic acid, (S)-(+)-2- phenyl-propionic acid and (R)-(-)-2-hydroxy-2-phenyl-propionic acid were used as the chiral terminal groups for the synthesis of four series of liquid crystals, series M、series P、series H and series D. Their structures are in the following scheme. The structures of these target molecules are varied in order to study the mesogenic properties deeply. The results indicate that the compounds【M-8】~【M-10】possess a SmC* phase and the average temperature range of this phase is 20℃. But in the series P the temperature range of SmC* phase for the compound【P-7】~【P-10】is 55℃. The mesophase sequence Cr-SmC*-SmA*-N*-I which is important for display application was found in the compounds of series D. The compound【D-8】~【D-10】have SmC*phase. Among these ferroelectric liquid crystals the compound【M-8】has the largest Ps value, 89.3 nC/cm2. The values of spoutaneous polarization for these liquid crystals are larger than theoe of the corresponding liquid crystals containing chiral alcohol moiety. This results is in accordance with the conclusions of the previous studies. SCHEME