Lanthanide complexes of Schiff base ligands containing three aromatic rings: synthesis and thermal behaviour

The synthesis and thermal behaviour of liquid-crystalline lanthanide comple xes with Schiff base ligands are described. The stoichiometry of the rare-e arth complexes is [Ln(LH)L-2(NO3)], where Ln = La(III), Nd(III), Pr(III), E u(III). Gd(III). Ho(III), Er(III), and LH is the Schiff base 4-({3-Hydroxy- 4-[(octadecylimino)methyl]phenoxy}carbonyl)phenyl 4-(hexyloxy)benzoate. The ligand displays a smectic C (SmC) and a nematic (N) phase. In the metal co mplexes, the nematic phase is suppressed and only a smectic C phase is pres ent. (C) 2001 Elsevier Science B.V. All rights reserved.