運用Schiff Base Salen化合物之膽固醇相液晶及CD光譜檢測金屬離子

Abstract

本論文合成出具有不同旋性之希夫鹼Salen結構的一系列分子，因Salen結構具有錯合金屬離子的能力，將其混入膽固醇相液晶，成為一可感測金屬離子之液晶感測器，藉由錯合金屬離子使分子本身旋性改變，進而影響膽固醇相液晶的螺距，使其反射光波長產生變化。此液晶感測器對於鋰離子( Li+ )有特別的選擇性，且不同旋性之分子在錯合鋰離子後，膽固醇相液晶反射光波長的位移也會有所不同。當分子旋性和另一chiral dopant旋性相同時，錯合鋰離子後，液晶反射光波長會紅位移；而分子旋性和另一chiral dopant旋性相反時，液晶反射光波長會藍位移。利用FT-IR光譜鑑定分子錯合金屬之官能基及利用CD光譜測量分子之旋性。

We synthesize a series of compounds with Schiff base Salen ligand which have different chirality, because Salen structure can complex metal ions, we dope these compounds to cholesteric liquid crystals and make them become a liquid crystal chemosensor. The chemosensors can detect metal ions by changing the pitch of cholesteric liquid crystal phases, when the wavelength of reflected light shift, we can see the color of cholesteric liquid crystal phases change by eyes. These liquid crystal mixtures have specific selectivity, only complexing lithium ions (Li+) can change the color of cholesteric liquid crystal phase. The compound has different chirality would make the wavelength of reflected light have different shiht. When two chiral dopants have the same chirality, the color of cholesteric liquid crystal phases would change from green to red, but when two chiral dopants have different chirality, the color of cholesteric liquid crystal phases would change from green to blue. We use FT-IR spectrum to identify the complex ligand of molecule functional groups and use CD spectra to measure molecule chirality.