ABSTRACT
A new series of liquid crystalline compounds has been synthesized by combining a Cyanostilbene-6 (CSB-6) core with alkoxy-substituted vanillic acid derivatives through ester and Schiff base linkages. The molecular design incorporates a highly conjugated and polar CSB-6 unit, known for its strong dipole moment and π–π stacking capability, along with vanillic acid moieties bearing varying alkoxy chain lengths to tune molecular flexibility and intermolecular interactions. The synthesized compounds were fully characterized using FT-IR, 1H NMR, 13C NMR, and elemental analysis. The mesomorphic behaviour was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). As the terminal chain length increased, a gradual shift in phase transition temperatures and the stabilization of smectic phases were observed. Additionally, density functional theory (DFT) calculations were performed to analyze the molecular geometry, dipole moment, frontier molecular orbitals, and electrostatic potential distribution provide valuable insights for the design of cyanostilbene-based mesogens.
References
- Bhanderi V.D., Katariya K.D., Nakum K. Cyanostilbene-based ester & Schiff base containing liquid crystals: Synthesis, mesomorphic studies and DFT calculations. Journal of Molecular Liquids 433 (2025) 127739.
- Huijie Yi., Jingjing G., Siyang L., Jiawei M., Jinbao G. Photoresponsive α-cyanostilbene-containing fluorescent liquid crystal polymers based on ring-opening metathesis polymerization for information storage and encryption. Polymer 258 (2022) 125289.
- Bian L., Zhang J., Wang J., C. Xiaofang Aggregation-Induced Emission-Active Cyanostilbene-Based Liquid Crystals: Self-Assembly, Photophysical Property, and MultiresponsiveBehavior. Molecules 29(23) (2024) 5811.
- Martínez-Abadía M., Varghese S., BegoñaMilián M., Gierschner J., Giménez R., et al. Bent-core liquid crystalline cyanostilbenes: fluorescence switching and thermochromism. Physical Chemistry Chemical Physics 17 (2015) 11715-11724.
- Bala I., Kaur H., Maity M., Yadav R.A., De, J., et al. Electroluminescent Aggregation-Induced Emission-Active Discotic Liquid Crystals Based on AlkoxyCyanostilbene-Functionalized Benzenetricarboxamide with Ambipolar Charge Transport. ACS Applied Electronic Materials 4(3) (2022) 1163–1174.
- Martínez-Abadía M., Robles-Hernández B., de la Fuente M.R., Giménez R., Ros M.B. Photoresponsive Cyanostilbene Bent-Core Liquid Crystals as New Materials with Light-Driven Modulated Polarization. Advance Materials. 28(31), (2016) 6586-6591.
- Mandle R.J., Gibb C.J., Hobbs J.L. Uncommon building blocks in liquid crystals. Liquid Crystals 51(8–9) (2024) 1384–1409.
- Nath S., Kappelt A., Spengler M., Roy B., Voskuhl J., et al. Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding. Beilstein Journal of Organic Chemistry 17 (2021) 124–131.
- Aixiang D., Guiyu Z., Hongbo L.U., Jiaxiang Y. α-Cyanostilbene Derivatives as Fluorescence Liquid-Crystal Molecules: Synthesis and Optical Properties. Chinese Journal of Applied Chemistry 31(11) (2014) 1261.
- Gong Y., Du C., Wang X., Guo H., Yang F. First stable (Z)-configuration of cyanostilbene derivative: An effective “turn-on“ fluorescent sensor for lysine in aqueous media, Microchemical Journal 162 (2021) 105866.
- Darji D.P., Pansuriya B.R., Labana B.M., Pandya V.B., Pandya A.D. Influence of substituents on thermal and electronic properties of 4-((E)-phenyldiazenyl)-2-((E)-((4-(alkyloxy)phenyl)imino)methyl)phenol derivatives. Molecular Crystals and Liquid Crystals 769 (2025) 418-436.
- Panchal J., Mali H., Sharma V.S., Parmar P., Shrivastav P.S., et al. Synthesis and characterization of calamitic liquid crystals based on benzothiazole-substituted aroylhydrazone: effect of terminal groups on phase behavior. Molecular Crystals and Liquid Crystals 769 (2025) 380-394.
Download all article in PDF
