本論文之分子設計，於含長烷鏈六炔苯基苯其中一外圍苯環上之烷鏈置換成烷氧鏈，並在苯環內側分別引入單氟及雙氟原子，期望當氟原子置於苯環內側能增加分子內側臂之間立體障礙，以降低分子上下堆疊秩序而傾向形成低溫向列型液晶，並比較氟原子數量對液晶及光學性質的探討。此類分子設計成功合成出具有低熔點(40 °C)且廣液晶溫度範圍(80 °C)之盤狀向列型液晶分子，相較於苯環外側引入雙氟原子之筒形液晶，在接近澄清點時不會因高溫而裂解。而引入雙氟原子在形成液晶相時，較易產生垂直配像排列(homeotropic alignment)。 According to lab member’s study results, introducing fluorine atoms at outside position on one of side chains in hexakis(phenylethynyl)benzene can reduce the temperature of the liquid crystal (LC) form, but the liquid crystal type is columnar, it has high order and viscosity, not suitable for display materials. In order to increase the intramolecular steric hindrance effect, I change the fluorine atoms to inside position to lower the order between molecules and form room temperature discotic nematic. I successfully synthesis the near room temperature (40 °C) discotic nematic and compare to above-mentioned columnar, it would not decomposed near clear point. In the other hand, introduce two fluorine atoms at inside position could caused homeotropic orientation than single fluorine atom.
