Macrocyclic and macropolycyclic heteroaromatic N-oxides: powerful sensitizers for the lanthanide ions emission

Heterocyclic ligands are common sensitizers for the lanthanide ions emissio n upon UV irradiation. Of particular interest are Tb(III) and Eu(III) ions in combination with acyclic, macrocyclic and macropolycylic ligands incorpo rating heterobiaryls, such as 2,2'-bipyridyl, 1,10-phenanthroline, 1,1'-biq uinoline, 3,3'-biisoquinoline, and their derivatives. Much more powerful se nsitizers are the same systems bearing N-oxide functions, furthermore their complexes are more stable than the parent heterocycles. Such luminescent m aterials are the basis for time-resolved fluoroimmunoassays displaying very high sensitivity, and serve as materials for advanced medical diagnostics. In this short review, a brief presentation will focus on state-of-the-art photochemistry and photophysics of the lanthanide complexes of heterocyclic and N-oxide-incorporating heterocyclic systems. (C) 2000 Elsevier Science S.A. All rights reserved.