Synthesis and physical property of liquid crystal compounds containing chiral α-alkyl benzyl alcohol

• Main Authors: Wang Chung Hao, 王俊豪
• Other Authors: 蔡文亮
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/65533037851632443267

碩士 === 國立高雄師範大學 === 化學系 === 91 === Abstract The compound, benzyl 4-(4'-octoxybiphenyl-4-carbonyloxy) benzoate,was first synthesized by Gray and coworkers. The result doesn't show that this compound is a liquid crystal. Lee of our laboratory has synthesized the same compound and proved that it do have mesogenic properties. When benzyl group is further substituted by (R)-α-methyl benzyl group, chiral smectic C phase can be formed. The liquid crystal phase sequence of the compounds of series1 is I－SmA－SmC*－K during the cooling process. The temperature range of SmC* phase is between 4∼32℃. It shows that chiral benzyl moiety will not restrain the formation of liquid crystal phases. The liquid crystal phase sequence of series2 is the same as that of series1. But alkyl size of the chrial center affects the formation of SmC* phase. When alkyl group is C9 H19, that compound doesn't have any liquid crystal phase. The liquid crystal phase of series3 is monotropic and the phase sequence of them is I－SmA－K during the cooling process. The reason for the phase difference between series 1 and 2 is not clear. Conformation change between them might be a reason. Series1 (n=7~10) 、 R=CH3 Series2 (n=8)、R= CH3、C2H5、C3H7、C9H19 Series3 (n=7~10)、 R=CH3