White luminescent silica layers: The molecular design beneath

The incorporation of luminescent lanthanide complexes in solid matrices with controlled structural organization is of widespread interest in materials science and has witnessed important improvements with the development of low-temperature soft chemistry solution processes, such as sol-gel. In this review, after an introductory part concerning some relevant aspects of the electronic and coordination properties of lanthanides, the prominent issues related to the design and synthesis of efficient luminescent antenna complexes, and their photophysical properties are presented. We describe the basic principles of ligands design to yield systems featuring a coordination site for the metal cation with appended suitable chromophores as sensitizers (two-component approach). When properly designed, these ligands are capable of forming highly luminescent complexes (overall sensitization yield, se > 0.05 in aqueous medium).