Alamro Fowzia S, Ahmed Hoda A, Alharbi Nuha Salamah, Al-Kadhi Nada S, Alhaddadd Omaima A, Naoum Magdi M, El-Atawy Mohamed A
Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
Department of Chemistry, Faculty of Science, Cairo University, Cairo 12613, Egypt.
ACS Omega. 2024 Jul 12;9(29):31601-31610. doi: 10.1021/acsomega.4c01564. eCollection 2024 Jul 23.
Ten new compounds based on the methineazo-azomethine (CH=N-N=CH) and ester linking groups were prepared and investigated for their mesophase behavior and optical stability, and liquid crystals of 4-substituted phenyl methineazo-azomethine phenyl 4-alkoxybenzoates, , were investigated. An alkoxy group with a length between 8 and 12 carbons is attached to the phenyl eater wing, while the other terminal ring is substituted in its 4-position with one of the polar NO, F, Cl, CHO, and N(CH) groups. The molecular structures of the newly prepared compounds were verified by using H NMR, C NMR, and elemental analysis. Differential scanning calorimetry and polarized optical microscopy were applied to investigate their mesophase behavior. All members of the prepared homologous series showed excellent thermal mesomorphic stability over wide temperature ranges. The geometrical and thermal properties of the investigated compounds were verified via density functional theory (DFT). The theoretical results revealed that all of the compounds are almost planar. Finally, the experimentally established values of the mesophase data were correlated with the predicted quantum chemical characteristics evaluated by DFT.
制备了十种基于次甲基偶氮-甲亚胺（CH=N-N=CH）和酯连接基团的新化合物，并对其介晶行为和光学稳定性进行了研究，同时研究了4-取代苯基次甲基偶氮-甲亚胺基苯基4-烷氧基苯甲酸酯类液晶。在苯基酯链段上连接了一个含有8至12个碳原子的烷氧基，而另一个端环在其4-位被极性基团NO、F、Cl、CHO和N(CH)中的一种取代。通过1H NMR、13C NMR和元素分析对新制备化合物的分子结构进行了验证。采用差示扫描量热法和偏光显微镜研究了它们的介晶行为。所制备的同系物系列的所有成员在很宽的温度范围内都表现出优异的热介晶稳定性。通过密度泛函理论（DFT）验证了所研究化合物的几何和热性质。理论结果表明，所有化合物几乎都是平面的。最后，将实验确定的介晶数据值与通过DFT评估的预测量子化学特征相关联。
