Luminescent columnar liquid crystals generated by self-assembly of 1,3,4-oxadiazole derivatives
作者:André A. Vieira、Hugo Gallardo、Joaquín Barberá、Pilar Romero、José Luis Serrano、Teresa Sierra
DOI:10.1039/c0jm04570e
日期:——
Five new V-shaped acids derived from 1,3,4-oxadiazole are described. These compounds were used to prepare supramolecular complexes via hydrogen bonding interactions with 2,4-diamino-6-dodecylamino-1,3,5-triazine in a 3 : 1 ratio. The formation of the complexes was evidenced by infrared and NMR techniques. All the complexes were studied by polarizing optical microscopy, differential scanning calorimetry and small-angle X-ray diffraction. Rectangular and hexagonal columnar mesophases were observed for the complexes at room temperature, without signs of crystallization. Circular dichroism studies demonstrated that, in the liquid crystalline state, these materials show supramolecular optical activity. It is proposed that this phenomenon arises due to a helical columnar organization. Furthermore, the complexes display strong blue light emission in solution, with good photoluminescence quantum yields, and in the mesophase. These materials could therefore be promising candidates for optoelectronic applications.
描述了五种衍生自 1,3,4-恶二唑的新型 V 型酸。这些化合物用于通过与 2,4-二氨基-6-十二烷基氨基-1,3,5-三嗪以 3 : 1 的氢键相互作用制备超分子复合物。通过红外和核磁共振技术证明了复合物的形成。通过偏光光学显微镜、差示扫描量热法和小角 X 射线衍射对所有配合物进行了研究。在室温下观察到配合物的矩形和六方柱状中间相,没有结晶迹象。圆二色性研究表明,在液晶状态下,这些材料表现出超分子光学活性。据推测,这种现象是由于螺旋柱状组织而产生的。此外,该配合物在溶液中和中间相中表现出强烈的蓝光发射,具有良好的光致发光量子产率。因此,这些材料可能成为光电应用的有希望的候选材料。