Thermotropic ruthenium(II)-containing metallomesogens based on substituted 1,10-phenanthroline ligands.
Imidazo[4,5-f]-1,10-phenanthroline and pyrazino[2,3-f]-1,10-phenanthroline substituted with long alkyl chains are versatile ligands for the design of metallomesogens because of the ease of ligand substitution. Whereas the ligands and the corresponding rhenium(I) complexes were not liquid-crystalline, mesomorphism was observed for the corresponding ionic ruthenium(II) complexes with chloride, hexafluorophosphate, and bistriflimide counterions. The mesophases were identified as smectic A phases by high-temperature small-angle X-ray scattering (SAXS) using synchrotron radiation. The transition temperatures depend on the anion, the highest temperatures being observed for the chloride salts and the lowest for the bistriflimide salts. The ruthenium(II) complexes are examples of luminescent ionic liquid crystals.
Cardinaels
Thomas
T
Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F-bus 2404, B-3001 Leuven, Belgium. thomas.cardinaels@chem.kuleuven.be
Ramaekers
Jan
J
Driesen
Kris
K
Nockemann
Peter
P
Van Hecke
Kristof
K
Van Meervelt
Luc
L
Goderis
Bart
B
Binnemans
Koen
K