由于其对诸如温度,机械力以及电场和磁场之类的外部刺激的敏感性,表现出热致液晶性质的分子已经变得非常重要。结果,通过在芳族核附近以及在侧链中引入各种官能团,已经合成了几种新颖的介晶,并且已经研究了它们的性质。在本研究中,我们报告了在一个末端带有羟基的三环液晶元。这些介晶通过多步路线合成,并通过光谱技术完成结构表征。通过热阶段光学偏振显微镜,差示扫描量热法和小角X射线散射研究了中间相性质。较低的同系物发现了对映向列相,而较高的同系物则发现了另外的近晶C相。固态高分辨率自然丰度已经对固相和中间相中典型的液晶元进行了13 C NMR研究。层列碳相和向列相的液晶元的13 C NMR光谱表明该分子在磁场中自发排列。通过利用称为SAMPI4的二维分离局部场(SLF)NMR实验,获得了13 C– 1 H偶极耦合,这些耦合用于确定液晶元的取向顺序参数。
由于其对诸如温度,机械力以及电场和磁场之类的外部刺激的敏感性,表现出热致液晶性质的分子已经变得非常重要。结果,通过在芳族核附近以及在侧链中引入各种官能团,已经合成了几种新颖的介晶,并且已经研究了它们的性质。在本研究中,我们报告了在一个末端带有羟基的三环液晶元。这些介晶通过多步路线合成,并通过光谱技术完成结构表征。通过热阶段光学偏振显微镜,差示扫描量热法和小角X射线散射研究了中间相性质。较低的同系物发现了对映向列相,而较高的同系物则发现了另外的近晶C相。固态高分辨率自然丰度已经对固相和中间相中典型的液晶元进行了13 C NMR研究。层列碳相和向列相的液晶元的13 C NMR光谱表明该分子在磁场中自发排列。通过利用称为SAMPI4的二维分离局部场(SLF)NMR实验,获得了13 C– 1 H偶极耦合,这些耦合用于确定液晶元的取向顺序参数。
Rodlike metallomesogens containing nickel(<scp>ii</scp>), palladium(<scp>ii</scp>) and copper(<scp>ii</scp>) based on novel enaminoketonato ligands
作者:Carsten P. Roll、Alexander G. Martin、Helmar Görls、Guido Leibeling、Daniel Guillon、Bertrand Donnio、Wolfgang Weigand
DOI:10.1039/b316731c
日期:——
Several new enaminoketone mesogens were synthesized and coordinated to various metal salts to yield a variety of novel rodlike metal-containing liquid crystals. The mesophases were characterized by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). Whereas the free ligands display SmA and nematic mesophases, the NiII and PdII complexes give rise to SmC and nematic phases, and the paramagnetic CuII mesogens to a narrow temperature-range nematic mesophase only. The magnetic behaviour of the latter was studied by means of EPR and magnetic susceptibility (SQUID) measurements.
Combined Stabilizing Effects of Trifluoromethyl Groups and Semifluorinated Side Chains on the Thermotropic Liquid‐Crystal Behavior of β‐Enamino Ketone Ligands and Their Bischelate Pd
<sup>II</sup>
Complexes
作者:Alexander Martin、Carolin Mügge、Douglas L. Gin、Bertrand Donnio、Wolfgang Weigand
DOI:10.1002/ejic.201402489
日期:2014.11
β-enamino ketoneligands and their corresponding bischelate PdII complexes bearing various combinations of methyl and trifluoromethylgroups at the chelating center as well as peripheral hydrocarbon and perfluorinated sidechains were prepared. The effect of these structural modifications on the thermotropic liquid-crystalline behavior of both the ligands and the corresponding metal complexes was studied
Synthesis and mesomorphic properties of novel Schiff base liquid crystalline EDOT derivatives
作者:Ashwathanarayana Gowda、Arun Roy、Sandeep Kumar
DOI:10.1016/j.molliq.2016.11.010
日期:2017.1
Herein, we reported novel banana liquid crystals derived from ethylenedioxythiophene (EDOT) central unit encompass with Schiff base. Structural charecterization of these compounds was carried out from their spectral and elemental analysis. Physical properties of all the newly synthesized compounds were investigated by polarising optical microscopy, differential scanning calorimetry, thermogravimetric
Effect of hydrogen-bonded supramolecular assembling on liquid crystal properties of imidazole-containing azomethines and their chelates with copper(II)
作者:Oleg N. Kadkin、Jigeon Tae、Eun Ho Kim、So Yeon Kim、Moon-Gun Choi
DOI:10.1080/10610270802709386
日期:2010.1
A series of imidazole-containing rod-like Schiff's bases and their ionic copper(II) chelates with various lengths of the terminal alkyl chain containing 6, 8, 10, 12, 14 and 16 carbon atoms have been synthesised. The synthesised compounds were characterised by elemental analyses, H-1 NMR, IR and UV-vis and mass spectroscopies. Thermotropic smectic C mesophases in the ligands and smectic A mesophases in the copper(II) complexes were identified using POM, DSC and small-angle XRD scattering methods. X-ray diffraction patterns of the prepared imidazole imines indicate to supramolecular self-assembled structures in the liquid crystal state, which are formed by means of intermolecular hydrogen bonds. It was established that both liquid crystal arrangement and supramolecular assemblies in ligands disappeared near 190 degrees C, mainly regardless of the lengths of the terminal alkyl chains. Contrary, assembling of the copper(II) complexes into supramolecular bilayers occurs near 200 degrees C, which causes their transition to a smectic A mesophase.
Kaharu, T.; Takahashi, S., Molecular Crystals and Liquid Crystals Science and Technology, Section A: Molecular Crystals and Liquid Crystals, 1994, vol. 257, p. 35 - 42