Preparation and magnetic properties of nitroxide radical liquid crystalline physical gels

ABSTRACT

Liquid crystalline physical gels which consist of a chiral racemic nitroxide radical compound (±)-1 showing a nematic phase and a diamagnetic, chiral organic gelator (R,R)-2 were prepared to investigate the effects of the gelator on the “positive magneto-LC effects” observed in the nematic phase of (±)-1 and the molecular alignment of (±)-1 in the resulting nematic gels. With the increasing amount of the gelator which decreased the domain size, the molecular reorientation by a magnetic field (0.34 T) was considerably restricted in the nematic gel phase and the intermolecular magnetic interactions (positive magneto-LC effects) increased in the fine and random nematic polydomain structure formed by self-assembled fibers of organic gelator molecules.

KEYWORDS:

• Magnetic liquid crystals
• liquid crystalline physical gels
• nitroxide radicals
• positive magneto-LC effects

Funding

This work was supported by JSPS KAKENI (Grant numbers 26248024 and 15J01040). YT is very grateful to the JSPS Research Fellowships for Young Scientists.