Synthesis and Characterization of Crown-Ether Appended Hexaazatrinaphthylene-Based Liquid-Crystalline Derivative

• Main Authors: Kyosuke Isoda, Keigo Shimooka
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Crystals
• Subjects: liquid crystals; sStimuli response; hexaazatrinaphthylene; electron acceptor
• Online Access: https://www.mdpi.com/2073-4352/10/5/377

In this article, we report on the synthesis and characterization of crown-ether appended hexaazatrinaphthylene derivatives with two alkoxy chains. The complexation of a derivative having shorter alkoxy chains with metal ions, such as NaI and KI, prompts remarkable changes in the electronic properties of sold states, because of changing intermolecular interactions. Polarized optical microscopic observation, X-ray diffraction pattern measurement and differential scanning calorimetry reveal that a compound with longer alkoxy chains self-assembles into the formation of the columnar liquid-crystalline phase. Moreover, the addition of benzenesulphonic acid influences the self-assembled liquid-crystalline structures, as well as the electronic properties. The complexation of the derivative having longer alkoxy chains with benzenesulphonic acid induces a larger dipole moment, compared to that before complexation, thereby leading to the enhancement of intermolecular interaction, such as dipole-dipole interaction. Also, peaks in UV-vis absorption and fluorescent spectra show a dramatically bathochromic shift, due to their intermolecular interaction, such as the π-π interaction.