Abstract
New liquid crystalline compounds containing carbazolyl moiety as part of the mesogenic group were synthesized. 2-(9-methylcarbazolyl)-4-cyanobenzoate and 2-(9-metylcarbazolyl)-4-alkanecarboxybenzoate show schlieren texture. 2-(9-methylcarbazolyl)-4-cyanobenzoate has two phase transition temperatures on both heating and cooling processes. By X-ray diffraction measurement of this compound, only one broad weak peak was detected at the mesomorphic temperature in the wide-angle region. Therefore, liquid crystalline phase of the compound was assigned to a nematic phase. 2-(9-Methylcarbazolyl)-4-pentynylcarboxybenzoate shows only one transition peak on heating process and two phase transition peaks on cooling process. By X-ray diffraction measurement, the compound indicates two broad peaks at around 4.5 and 19.0 degree respectively. Liquid crystalline phase of the compound would be assigned to a cybotactic nematic phase based on the shorten molecular length compared with the calculated value and the optical texture.
