Thiophene-Derivatized Pybox and Its Highly Luminescent Lanthanide Ion Complexes

摘要

Lanthanide ion complexes have application in areas ranging from fluoroimmunoassays to materials science because of their light emission properties. The luminescence is due to parity-forbidden and spin-forbidden f—f transitions, requiring thus the use of ligands as sensitizers. Numerous ligand designs have been described, from simple 2,6-pyridinedicarboxylic acid, shown to sensitize near-IR emission of Yb(III) and utilized in standards for the determination of quantum yields of emission, to more complex chelating architectures, capable of discriminating between different lanthanide ions and of yielding complexes with high quantum yields of luminescence. Although pyridine-bis(oxazoline), Pybox, and its derivatives were extensively utilized by Aspinall and co-workers6"8 in lanthanide ion complexes for enantioselective catalysis, they have never been reported as sensitizers for lanthanide luminescence. This ligand is extremely versatile, as it allows straightforward deriva-tization of the para position of the pyridine ring, as well as of the carbon atoms of the oxazoline ring.