Formation of Columnar Liquid Crystals on the Basis of Unconventional Triazine-Based Dendrimers by the<i>C</i><sub>3</sub>-Symmetric Approach
作者:Long-Li Lai、Shun-Ju Hsu、Hui-Chu Hsu、Sheng-Wei Wang、Kung-Lung Cheng、Chun-Jung Chen、Tsai-Hui Wang、Hsiu-Fu Hsu
DOI:10.1002/chem.201103423
日期:2012.5.21
Two series of unconventional triazine‐based dendrimers with C2 symmetry and C3 symmetry were prepared. The newly prepared C3‐symmetrical dendrimers were characterized by 1H and 13C NMR spectroscopy, mass spectrometry, and elemental analysis. Differential scanning calorimetry, polarizing microscopy, and powder XRD showed that the C3‐symmetrical dendrimers display columnar liquid‐crystalline phases during
制备了两个具有C 2对称性和C 3对称性的非常规的基于三嗪的树状大分子。通过1 H和13 C NMR光谱,质谱和元素分析对新制备的C 3对称树枝状聚合物进行了表征。差示扫描量热法,偏光显微镜和粉末XRD结果表明,在热处理过程中C 3对称树枝状大分子显示出柱状液晶相,但未观察到C 2对称树枝状大分子的行为。C 3 ‐和C的分子构象通过计算机模拟,在气相中用CaChe程序的MM2模型获得2个对称的树枝状大分子。仿真结果合理地解释了C 3-和C 2-对称树枝状聚合物的不同介晶性。此新策略应适用于其他类型的具有刚性骨架的非常规树枝状聚合物,以显示柱状液晶行为。