Development of ionic liquid crystals based on pyridinium and picolinium cations

• Published in: Liquid crystals today Vol. 32; no. 1; pp. 4 - 11
• Main Author: Santos, Andreia F. M.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02.01.2023; Taylor & Francis Ltd
• Subjects: Alkylation; Crystals; Dielectric Spectroscopy (DS); Differential Scanning Calorimetry (DSC); Functional materials; Ionic liquid crystals; Ionic liquids; Ions; Liquid crystals; Microscopy; Organic salts; Polarised Optical Microscopy (POM); pyridinium & picolinium salts; Solvents; X-Ray Powder Diffraction (XRD)
• ISSN: 1358-314X; 1464-5181
• DOI: 10.1080/1358314X.2023.2221615

The search for novel materials and technologies with improved performance increased in the last decades. In particular, ionic liquid crystals (ILCs), a modern class of advanced materials that benefits from the synergistic properties of ionic liquids and liquid crystals, are playing an important role in different areas of knowledge, attracting the interest of the academia and industry, driven by their peculiar tailoring ability. Herein, it comprises a brief synopsis of several pyridinium and picolinium ILCs previously prepared to understand how their mesomorphism and conductivity profiles are affected by small structural changes in terms of the methyl group position and alkyl chain length, providing important insights into future design of functional materials by a simple anionic exchange. Moreover, microwave-assisted reactions were emphasised as a simple and greener synthetic method to prepare ionic liquid crystals through alkylation, which can also be applied to other organic salts.