Current developments and future perspectives on the formation of luminescent lanthanide supramolecular self-assembly architectures with a focus on nitrogen-based donor ligands

helical, tetrahedral, cubic and other polyhedra). The influences of counter-anions, concentrations, metal:ligand ratios and solvents are also discussed. The fascinating new developments within mechanically interlocked molecules containing lanthanide ions are highlighted with a focus on their structural complexity and reversible binding properties. Furthermore, this review will focus on the functional properties of lanthanide assemblies including their temperature-dependent luminescence, host-guest interaction and aggregation-induced emission. The use of such ligands in metallo-supramolecular polymers is briefly discussed, including their application in the generation of luminescent hydrogels, supramolecular polymers and other conventional polymers. We conclude this review with the perspective of exploring the biological properties and toxicity of lanthanide complexes, their application in imaging, and the recovery of lanthanides for sustainable use as well as their promising applications in smart materials, sensing and diagnostics.