Luminescent lanthanide-based single-molecule magnets

Over the past decade, the groundbreaking integration of lanthanide ions into SMM design has undergone a profound transformation in this realm of research. The integration has spurred a concerted effort to combine magnetic properties with other distinct physical attributes, resulting in the development of truly multifunctional materials. Luminescent Lanthanide-Based Single Molecule Magnets (LL-SMMs) represent an exciting class of versatile coordination compounds. These compounds consist of lanthanide ions intricately coordinated with either organic or inorganic ligands, resulting in the creation of single or cluster lanthanide SMM structures. These structures showcase both luminescence and slow relaxation of the magnetization. This review summarizes the latest advances achieved within this dynamic field of study. It delves into the fundamental guiding principles of design while drawing insightful comparisons between the magnetic and optical traits exhibited by the best classes of luminescent SMMs, namely those featuring Dy3+, Yb3+, Tb3+, Er3+, Nd3+, and Ho3+ ions. Of particular significance is the exploration of the exciting potential to establish connections between magnetic and optical properties. Additionally, special attention is directed towards the emerging class of multifunctional SMMs, which ingeniously combine magnetic properties with luminescence thermometry, opening up new avenues of innovation.