Isoxazoline- and isoxazole-liquid crystalline schiff bases: A puzzling game dictated by entropy and enthalpy effects
作者:Luma Fritsch、Luis A. Baptista、Ivan H. Bechtold、Guilherme Araújo、Richard J. Mandle、Aloir A. Merlo
DOI:10.1016/j.molliq.2019.111750
日期:2020.1
Two series of Schiff base (SB) liquid crystals (LC) containing the 5-membered rings isoxazoline or isoxazole were synthesized and characterized; 27 isoxazoline and 20 isoxazole compounds were obtained. Nematic, smectic A, and smectic C mesophases were found and characterized by Polarized optical microscopy (POM), Differential scanning calorimetry (DSC), and X-ray diffraction. The scientific problem
合成并表征了含有5元环异恶唑啉或异恶唑的两系列席夫碱(SB)液晶(LC)。得到27个异恶唑啉和20个异恶唑化合物。找到了向列,近晶A和近晶C中间相,并通过偏振光学显微镜(POM),差示扫描量热法(DSC)和X射线衍射对其进行了表征。解决的科学问题是异恶唑啉环和异恶唑环如何影响中间相结构和稳定性。基于焓和熵性质的分子堆积和各向异性相互作用被用来解释两个系列的热和结构行为。所提出的机理得到密度泛函理论(DFT)计算的辅助,从而为这种系统的分子组织提供了新的见解。