Polarized Luminescence of Lanthanide Coordination Compounds

Luminescence of lanthanide (Ln) complexes sharply appears due to the ff-electronic transition at the inner orbital of Ln ion, which is induced by the energy transfer from the aromatic ligand with high absorption coefficients, so called the photo-antenna effect. The circularly polarized luminescence (CPL) of Ln ions in their coordination compounds depends on the molecular chirality and chiral aggregations. The dissymmetry factors of ff-emissions in Ln complexes tend to be larger than those in organic luminophores because of the intent electric dipole moments as a nature of Lns' transitions. Actually, the highest value of above factor in recent decades was recorded to 1.4 of molecular aggregation system of europium complexes with camphor derivatives. Taking advantage of this high environmental sensitivity, some sensors induce circular polarization by mixing achiral complexes and amino acids in solution. In this chapter, we present the CPL of Ln complexes from the principle and history of publication with topics relating to the actinoid, imaging systems of the films, and linearly polarized luminescence.