Europium(III) and Terbium(III) Luminescent Lanthanidomesogens

Liquid-crystalline columnar phenanthroline-based ligand, for the first time substituted in 4,7-positions, is synthesized and used to induce low temperature mesomorphism in his corresponding lanthanide complexes. Stable liquid crystalline Eu(III) and Tb(III) complexes with low transition temperatures and low viscosity mesophases are obtained and their thermal and photophysical properties investigated as a function of their different solid, soft and liquid crystalline organisations. The eight-coordination around the metal lanthanide centre is further fulfilled by six oxygen atoms of three bidentate 1-phenyl-3-methyl-4-benzoylpyrazol-5-one proligands.