Journal of rare earths vol:20 issue:4 pages:249-255
Lanthanide complexes of a steroid-substituted benzoerown ether were synthesised. The metal-to-ligand ratio of all the metal complexes is 1 : 1. The ligand 4'- [ (cholesteryloxy) carbonyl]-benzo-15-crown-5 is a monotropic liquid crystal, displaying a cholesteric mesophase. The lanthanide complexes with nitrate counter-ions form a highly viscous mesophase, decomposing at the clearing point. The transition temperatures change as a function of the lanthanide ion. The corresponding lanthanide complexes with dodecylsulphate ( DOS) counter-ions do not form a mesophase. In both cases, the metal complexes have a much lower melting point than the parent ligand.