Lanthanide complexes for CPL applications in materials
Résumé
Lanthanide complexes are well-known for their characteristic f–f forbidden transitions, leading to sharp emission bands and long luminescence lifetimes. Among these transitions, some are magnetic dipole-allowed, making the lanthanide complexes particularly attractive for applications involving Circularly Polarized Luminescence (CPL).1 CPL is the differential emission of left- and right-circularly polarized light by chiral emitters. Its intensity is quantified by the dissymmetry factor (glum), with values ranging between –2 and +2.2 In this context, Gunnlaugsson’s pyridine-diamide ligands are interesting due to their ability to form stable, chiral helical complexes with lanthanide ions. These chiral complexes have shown good CPL properties with reported glum values up to 0.3.3 The goal of this project is to synthesize chiral lanthanide complexes, designed for incorporation into materials. Based on the Gunnlaugsson scaffold, the ligands are modified with light-harvesting antennae to improve excitation efficiency and to change the properties of the resulting materials. Finally, the integration of these chiral complexes into materials such as PDMS aims to develop new standards for CPL microscopy and to create mechanically responsive systems.