Lanthanide Supramolecular Systems

This brief chapter reviews fundamental properties of luminescent trivalent lanthanide ions in the context of supramolecular systems. The first section begins with the electronic configuration and discusses its dominating role in the distinctly unique electronic, magnetic, coordination and optical properties across the lanthanide series. The basics of their photophysical properties such as absorption and emission properties as well as the process of sensitizing lanthanide luminescence (antenna effect), the energy transfer pathways and mechanisms are introduced as well. The second section explores in depth the photophysical properties including the hydration state, luminescence quantum yields, sensitization efficiency and the use of cryo-spectroscopy for evaluating the energy transfer process. The interpretation of the vastly informative luminescence transitions of Eu(III) is presented and the section concludes with an introduction to circularly polarized luminescence by Ln(III). The third section summarizes various representative self-assembled supramolecular Ln(III) systems categorized by the nature of ligands and molecular architecture. The fourth section discusses the translation of supramolecular Ln(III) systems into a wide variety of applications in aspects such as bio-sensing, medical imaging, single-molecule magnets and so on.