Liquid-crystalline behaviors of lanthanide complexes containing hemicyanine

The liquid crystalline behaviors of four lanthanide complexes, (E)-N-hexadecyl-4-(2-(4-(dimethylamino)phenyl)ethylene)pyridinium tetrakis(1-phenyl-3-methyl-4-benzoyl-5-pyrazolonato)lanthanide(La, Nd, Dy and Yb)(III) have been investigated by using differential scanning calorimetry (DSC), thermogravimetric and differential thermal analysis (TG-DTA) and polarized optical microscopy. Except for the lanthanum complex, the other three complexes display mesogenic behavior with typical smectic mosaic textures. This is the second report on lanthanide metallomesogens since a discotic mesophase of substituted bis(phthalocyanine)lutetium was found.