Coordination‐Assembled Lanthanide‐Organic Ln3L3 Sandwiches or Ln4L4 Tetrahedron: Structural Transformation and Luminescence Modulation

Summary of main observation and conclusion Photo‐functional supramolecular lanthanides assemblies have shown great potential in the materials and biomedical fields. Two new tri(tridentate) ligands ( L3 and L4 ) highlighting small variation of the connection position to the central tridentate linkers have been designed, which leads to the emergent formation of either Ln 3 L 3 ‐type sandwich structures or Ln 4 L 4 ‐type tetrahedral cages. Moreover, nonlinear enhancement of lanthanide luminescence based on the modulation of inter‐ligand charge‐transfer states has been revealed on the mix‐ligand Ln 3 L 3 sandwiches. Our results provide important guidance for structure‐design and photoluminescence optimization of supramolecular lanthanide‐organic assemblies.