A new class of thermotropic lanthanide mesogens: Eu(III) nitrate complexes with mesogenic 4-pyridone ligands

A new class of thermotropic lanthanido mesogens has been designed and prepared. They are based on 4-pyridone ligands that possess mesogenic cyanobiphenyl groups attached to the 4-pyridone unit via a flexible long alkyl spacer and show a very high thermal stability (decomposition temperatures near 300 °C).
Depending on the alkyl length spacer, these complexes exhibit a SmA phase with transition temperatures influenced by the number of mesogenic groups employed and the spacer length.