Magnetically Manipulable Ionic Liquid Crystals Incorporating Neutral Radical Moiety

Chempluschem. 2022 Mar;87(3):e202100352. doi: 10.1002/cplu.202100352. Epub 2021 Oct 12.

Abstract

With a view to fabricating a new remote input-output system by applying functional ionic liquid crystalline (ILC) materials, we have developed novel ILC compounds containing a nitroxide radical unit in the organic cations, which show an enantiotropic smectic A (SmA) phase. We have implemented the magnetic manipulation of a droplet of one of the ILC compounds on the basis of the intermolecular magnetic interactions between radical moieties. This ILC monoradical compound shows a 55 % larger increase in paramagnetic susceptibility at the solid-to-LC melting point in the first heating process than the non-ionic LC monoradical compounds. It is most likely owing to the nanosegregation of strongly bonded ionic and non-ionic moieties. The increased molar magnetic susceptibility is preserved not only in the SmA phase but also in the isotropic liquid and solid phases during the first cooling process.

Keywords: ionic liquid; liquid crystal; magnetism; radicals; smectic phases.