Optical sensitization and upconversion in discrete polynuclear chromium–lanthanide complexes

Due to its extreme kinetic inertness, trivalent chromium, Cr(III), has been rarely combined with labile trivalent lanthanides, Ln(III), to give discrete self-assembled (supra)molecular polynuclear complexes. However, the plethora of accessible metal-centered excited states possessing variable lifetimes and emissive properties, combined with the design of efficient intramolecular Cr(III) ↔ Ln(III) energy transfer processes open attractive perspectives for programming directional light-conversion within these heterometallic molecules. Efforts made to address this exciting challenge for both light-sensitization and light-upconversion are discussed in this article.

► Photophysical outputs arising from chromium(III)–lanthanide(III) communications. ► Synthetic strategies for the preparation of discrete polynuclear Cr–Ln complexes. ► Characterization of discrete polynuclear Cr–Ln complexes. ► Optical sensitization in discrete polynuclear Cr–Ln complexes. ► Optical upconversion in discrete polynuclear Cr–Ln complexes.