Anisotropic and Inhomogeneous Magnetic Interactions Observed in All-Organic Nitroxide Radical Liquid Crystals

An anisotropic and inhomogeneous magnetic interaction (the average spin−spin interaction constant J̅> 0) was observed in the various liquid crystalline (LC) phases of racemic and nonracemic all-organic radical LC compounds 1aand 1b. We discussed how the LC superstructures induced the magnetic interaction to operate in the LC phases in terms of spin−spin dipole and exchange interactions by means of VT-EPR spectroscopy. The magnitude of the magnetic interaction depended on the type of LC phase, or the superstructure. Furthermore, these radical LC droplets floating on water were commonly attracted to a permanent magnet and moved freely under the influence of this magnet, whereas the crystallized particles of the same compounds never responded to the magnet. The response of the LC droplets to the magnet also varied depending on the type of LC phase, that is, the extent of the magnetic interaction.