The first examples of achiral bent-core molecules consisting of an azo linkage and five aromatic rings exhibiting bent-core mesophases are reported. They exhibit B1 and B2 phases as identified by optical microscopy, differential scanning calorimetry, X-ray diffraction, and electro-optical techniques. The B2 phase of these materials is identified to be the anticlinicâantiferroelectric, SmCAPA phase. The mesophases of these compounds have relatively low transition temperatures and wide temperature ranges. The observation of bent-core phases in azo compounds assumes significance from the fact that the introduction of the âNNâ linkage adds a new dimension, namely photochromism, to this field.
本研究首次报道了由偶氮连接和五个芳香环组成的非手性弯核分子的例子,这些分子表现出弯核介相。通过光学显微镜、差示扫描量热仪、X 射线衍射和电光技术鉴定,它们呈现出 B1 和 B2 相。经鉴定,这些材料的 B2 相为反折泛
铁电性 SmCAPA 相。这些化合物的介相具有相对较低的转变温度和较宽的温度范围。在偶氮化合物中观察弯曲核相的意义在于,âNNâ连接的引入为该领域增添了一个新的维度,即光致变色。