Room temperature imidazolium linked chalcone based ionic LCs: Role of terminal position on mesomorphism

• Published in: Journal of molecular structure 2022-12, Vol.1270, p.133834, Article 133834
• Main Authors: Chaudhari, Mayur, Sharma, Vinay S., Ganga, Venkata Subba Rao, Sharma, Anuj S., Mali, Hitendra, Shrivastav, Pranav S.
• Format: Article
• Language: English
• Subjects: Chalcone; Enantiotropical; Ionic liquid crystal; Nematic; Smectic C
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.133834

•Newly ionic imidazolium linked chalcone based LCs has been design and synthesized.•Structure property relationship has been studied in both series (ionic LCs).•Some ionic LCs adopted room temperature LC phase.•Smectic and nematic type mesophase reported in ionic linear and non-linear mesogens. A newly imidazolium linked chalcone ionic LCs (5a-5e, series-1) & (8a-8e, series-2) based on two phenyl rings have been synthesized by the quaternization of 1-methylimidazole and ortho & para-substituted hydroxy chalcone derivatives. The mesogenic behavior of synthesized ionic mesogens was perceived by POM, DSC and XRD measurements. The structure-property relationship of new class of chalcone linked imidazolium ILCs has been studied. All materials exhibited enantiotropical type mesogenic properties. Few selected ionic derivatives showed LC properties at room temperature with higher temperature range. Smectic C and nematic properties were detected in synthesized ionic compounds. Series-2 showed higher thermal stability of smectic and nematic phase as compared to series-1. The X-ray configurations revealed the coexistence of bilayer smectic C pattern over a well-defined temperature range. The molecular structures of target ILCs were identified by using IR and 1H NMR spectroscopy. [Display omitted]