Magnetization and Anisotropy of Magnetic Susceptibility of a Liquid Crystal Doped with Chlorophylls a, b and Carotenoids

The magnetization and anisotropy of magnetic susceptibility of a 5CB nematic liquid crystal doped three extracts containing chlorophylls a and b and carotenoids in different weight percentage has been studied. The extracts have been dissolved in the liquid crystal matrix at a concentration of 2%. The magnetic susceptibility of the substances has been measured by the Faraday-Curie balance method. The field σ(<i>H</i>) and temperature Δχ(<i>T</i>) dependences of molar magnetizations σ and anisotropy of magnetic susceptibility Δχ for the investigated objects have been obtained. The divergence of the σ(<i>H</i>) dependences for the extracts dissolved in the liquid crystal matrix and in acetone has been found. The growth of the Δχ values in the Δχ(<i>T</i>) dependence with an increase in the weight percentage of chlorophylls in the extracts has been established. The influence of molecules of the dopants on the anisotropy of magnetic susceptibility has been evaluated with allowance for the π-electron currents in the conjugated systems of the benzene rings and in the porphyrin nuclei of chlorophylls, as well as in chemical bonds of the aliphatic fragments.