Aromatic Heterocycles Used as Terminal Groups of Calamitic Liquid Crystals

Three series of compounds 1‐21 were prepared by using 2‐, 3‐, and 4‐pyridinemethanol as terminal group of calamitic liquid crystals. These compounds have some similarities in their phase behavior. They all exhibit SmA phase. A tilt smectic phase, SmC, will be formed when their flexible alkoxy chain is longer than hexoxy group. The profound difference between them is that the compounds 15‐17 possess a short temperature range of N phase. The compounds 3 and 6 have the widest SmA phase, up to 94 °C, and SmC phase, up to 46 °C, respectively. Three aromatic heterocycles such as 2‐, 3‐, and 4‐pyridinemethanol were used as terminal groups of liquid crystals. All the compounds 1‐21 prepared possess different smectic phases including tilted SmC phase. Some of them with a terminal 4‐pyridyl ring exhibit an additional N phase. The temperature range of SmA and SmC phase is up to 94 °C and 46 °C respectively.