Contrasting effects of heterocycle substitution and branched tails in the arms of star-shaped molecules
作者:Suraj Kumar Pathak、Subrata Nath、Joydip De、Santanu Kumar Pal、Ammathnadu S. Achalkumar
DOI:10.1039/c7nj00911a
日期:——
the reduction of their melting points and enhances their mesophase width. The presence of bulky branched tails at their peripheries enhances the intermolecular interactions between the cores of the 1,3,4-oxadiazole based TSANs, which leads to the stabilization of the columnar rectangular phase. The 1,3,4-thiadiazole based TSANs exhibit a columnar rectangular phase even with straight peripheral chains
本文中,合成并表征了包含基于1,3,4-恶二唑和1,3,4-噻二唑的星型三(N-水杨基苯胺)(TSAN)。在它们的周边引入支链尾部对这些三不同的效果(Ñ-salicylideneaniline),这取决于杂环的类型。与带有十六烷基氧基链类似物的高温柱状六角相相比,带有1,3,4-恶二唑臂的带有分支尾巴的TSAN表现出室温的柱状矩形相。对于基于噻二唑的TSAN,具有十六烷氧基链的化合物在包括室温在内的宽温度范围内均呈柱状矩形相,而其支链类似物为液体。因此,在星形分子的情况下,与常规盘状液晶相反,外围尾部的类型不仅影响转变温度,而且影响自组装的类型。引入替代1,3,4-噻二唑环有助于降低其熔点并增加其中间相的宽度。在其外围存在大体积的分支尾巴增强了基于1,3,4-恶二唑的TSAN核之间的分子间相互作用,从而导致了柱状矩形相的稳定化。基于1,3,4-噻二唑的TSAN甚至具有直的外围链也显示出柱状