Effect of Magnetic and Electric Field on the Orientation of Rare-Earth-Containing Nematics

Andrey A Knyazev; Aleksandr S Krupin; Aleksandr P Kovshik; Yuriy G Galyametdinov

doi:10.1021/acs.inorgchem.0c02500

Effect of Magnetic and Electric Field on the Orientation of Rare-Earth-Containing Nematics

Inorg Chem. 2021 Jan 18;60(2):660-670. doi: 10.1021/acs.inorgchem.0c02500. Epub 2020 Dec 29.

Authors

Andrey A Knyazev¹, Aleksandr S Krupin¹, Aleksandr P Kovshik², Yuriy G Galyametdinov¹

Affiliations

¹ Physical and Colloid Chemistry Department, Kazan National Research Technological University, 420015 Kazan, Russia.
² Department of Molecular Biophysics and Polymer Physics, Saint Petersburg State University, 199034 Saint Petersburg, Russia.

PMID: 33372755
DOI: 10.1021/acs.inorgchem.0c02500

Abstract

We report rare-earth-containing metallomesogens with newly synthesized ligands represented by the β-diketone 1-(4-(4-propylcyclohexyl)phenyl)octane-1,3-dione (CPDk_3-5) and the Lewis base 5,5'-bis(heptadecyl)-2,2'-bipyridine (bpy_17-17). The stoichiometry of the complexes is [Ln(CPDk_3-5)₃bpy_17-17], where Ln is a trivalent rare-earth ion (La, Sm, Eu, Gd, Tb, Dy, Ho, Tm, and Yb). Although the ligands themselves do not form any mesophase, the respective metal complexes produce nematic and smectic A phases. The mesogenic rare-earth complexes were characterized by NMR, MS, POM, DSC, X-ray diffraction, magnetic susceptibility measurements, and dielectric spectroscopy. The metal complexes display a remarkably large magnetic anisotropy in the mesophase. These nematic liquid crystals can, therefore, be easily aligned by an external low-threshold magnetic field.