Wide nematic phases induced by hydrogen-bonding
Wide nematic phases induced by hydrogen-bonding
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DOI：
10.1080/02678292.2018.1512664
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发表时间：
2019-03-16
期刊：
影响因子：
2.2
通讯作者：
Naoum, M.
中科院分区：
文献类型：
--
作者：
Ahmed, H. A.;Hagar, M.;Naoum, M.
制备了一系列新的氢键超分子配合物 In/IIm，并研究了它们的中间相行为。该配合物是通过等摩尔量的4-烷氧基苯基偶氮苯甲酸作为质子供体和非介晶4-烷氧基苯基偶氮吡啶作为质子受体之间的氢键作用制备的。超分子复合物的两个末端的末端烷氧基链的长度有系统地变化。通过差示扫描量热法 (DSC) 和 FTIR 光谱证实了 1:1 氢键配合物的形成。所有新复合物均通过 DSC 和偏光显微镜 (PLM) 进行表征。结果发现，所制备的配合物是二晶型的，具有范围相对较宽的近晶C（SmC）相和向列（N）相。将本系列配合物与之前研究的简单 4-烷氧基苯甲酸与 4-(4MODIFIER LETTER PRIME-pyridylazopheny)-4MODIFIER LETTER PRIME-alkoxyBenzates 的异构体进行比较，揭示向列相的稳定性取决于酸组分的长度。[图表]。
New series of hydrogen-bonded supramolecular complexes, In/IIm, were prepared and investigated for their mesophase behaviour. The complexes were prepared through hydrogen-bonding between equimolar amounts of 4-alkoxyphenylazo-benzoic acids as the proton donors and non-mesomorphic 4-alkoxyphenylazo pyridines as the proton acceptors. The length of the terminal alkoxy chains was varied systematically on both terminals of the supramolecular complexes. The formation of 1:1 hydrogen-bonded complexes was confirmed by differential scanning calorimetry (DSC) and FTIR spectroscopy. All of new complexes were characterised by DSC and polarised light microscopy (PLM). It was found that the prepared complexes are dimorphic, possessing smectic C (SmC) and nematic (N) phases with relatively wide ranges. A comparison was made between the present series of complexes and the previously investigated isomers of the simple 4-alkoxybenzoic acids with the 4-(4MODIFIER LETTER PRIME-pyridylazophenyl)-4MODIFIER LETTER PRIMEMODIFIER LETTER PRIME-alkoxybenzoates, revealed the stability of the nematic phase is dependent on the length of the acid component.[GRAPHICS].