Preparation and magnetic properties of nitroxide radical liquid crystalline physical gels.

Liquid crystalline physical gels which consist of a chiral racemic nitroxide radical compound (±)-1showing a nematic phase and a diamagnetic, chiral organic gelator (R,R)-2were prepared to investigate the effects of the gelator on the “positive magneto-LC effects” observed in the nematic phase of (±)-1and the molecular alignment of (±)-1in 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. [ABSTRACT FROM AUTHOR]