Luminescent materials with liquid-crystalline properties at room temperature were obtained by doping the nematic liquid-crystal host matrices MBBA and 5CB with the europium(III) b-diketonate complex [Eu(TTA) 3 (phen)]; very well resolved crystal-field fine structure is observed in the europium(III) emission spectra.
The first near-infrared photoluminescent liquid-crystalline material has been made by doping the nematic liquid-crystalline matrix MBBA with the lanthanide(III) beta-diketonate complexes [Nd(dbm)(3)(phen)], [Er(dbm)(3)(phen)] and [Yb(dbm)(3)(phen)], respectively. The photo luminescence intensity of the ytterbium(III) sample increases by 100% when the isotropic phase is cooled to the nematic phase
The liquid-crystalline rare-earth complexes of the type [Ln(LH)3(DOS)3]-where Ln is Tb, Dy, Ho, Er, Tm, or Yb; LH is the Schiff base N-octadecyl-4-tetradecyloxysalicylaldimine; and DOS is dodecylsulfate-exhibit a smectic A phase. Because of the presence of rare-earth ions with a large magnetic anisotropy, the smectic A phase of these liquid crystals can be easier aligned in an external magnetic field than smectic A phases of conventional liquid crystals. The magnetic anisotropy of the [Ln(LH)3(DOS)3] complexes was determined by measurement of the temperature-dependence of the magnetic susceptibility using a Faraday balance. The highest value for the magnetic anisotropy was found for the dysprosium(III) complex. The magnetic alignment of these liquid crystals was studied by time-resolved synchrotron small-angle X-ray scattering experiments. Depending on the sign of the magnetic anisotropy, the director of the liquid-crystalline molecules was aligned parallel or perpendicular to the magnetic field lines. A positive value of the magnetic anisotropy (and parallel alignment) was found for the thulium(III) and the ytterbium(III) complexes, whereas a negative value of the magnetic anisotropy (and perpendicular alignment) was observed for the terbium(III) and dysprosium(III) complexes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.