Determination of structural characteristics of all-organic radical liquid crystals based on analysis of the dipole-dipole broadened EPR spectra.
The angular dependences of g-value and line width of EPR spectra of paramagnetic all-organic liquid crystalline (LC) materials were measured for the quantitative characterization of the nematic, cholesteric, and smectic C phases. The detailed molecular alignment in mesophases was determined by means of numerical spectra simulation focusing on spin exchange and dipole-dipole magnetic interactions of neighboring molecules. The obtained structural data indicate that the spin polarization mechanism between neighboring molecules rather than the direct through-space interactions between paramagnetic centers is responsible for the specific magnetic properties of the studied LC materials.
Department of Chemistry, M.V. Lomonosov Moscow State University , Moscow 119992, Russian Federation.
A Kh
AKh
Vorobiev
N A
NA
Chumakova
D A
DA
Pomogailo
Y
Y
Uchida
K
K
Suzuki
Y
Y
Noda
R
R
Tamura