Self-Assembly of Triple-Stranded Lanthanide Molecular Quasi-Lantern Containing 2,2′-Bipyridine Receptor: Luminescence Sensing and Magnetic Property

[Image: see text] Ln(2)L(3)-type supramolecular architectures have received significant attention recently due to their unique magnetism and optical properties. Herein, we report the triple-stranded Ln(2)L(3)-type lanthanide molecular quasi-lanterns, which are fabricated by the deprotonation self-assembly of a linear ligand featuring a β-diketone chelating claw and 2,2′-bipyridine (bpy) moiety with lanthanide ions (Ln = Eu(3+) and Dy(3+)). The crystal structure analysis indicates that Eu(3+) and Dy(3+) ions are all coordinated by eight oxygen donors but in different coordination geometries. The eight oxygen donors in Eu(2)L(3) and Dy(2)L(3) are arranged in a square antiprism and triangular dodecahedron geometry, respectively. Taking into account the fact that the bpy moiety has a strong coordination affinity for transition metal ions, luminescence sensing toward Cu(2+) ions has been demonstrated with Eu(2)L(3), bearing a detection of limit as low as 2.84 ppb. The luminescence sensing behavior of Eu(2)L(3) is ascribed to the formation host–guest complex between Eu(2)L(3) and Cu(2+) ions with a 1:2 binding ratio. Dynamic AC susceptibility measurements for Dy(2)L(3) reveal the relaxation of magnetization in it. This work provides a potential way for design and fabrication of lanthanide-based molecular materials with functions endowed by the ligands.