Giant Crown-Shaped Dy 34 Nanocluster with High Acid-Base Stability Assembled by an out-to-in Growth Mechanism.

Lanthanoid metal ions have large ionic radii, complex coordination modes, and easy distortion of coordination spheres, but the design and synthesis of high-nucleation lanthanoid clusters with high stability in solution (especially aqueous solution) are challenging. Herein, a diacylhydrazone ligand (H 2 L 1 ) with multidentate chelating coordination sites was used to react with Dy(OAc) 3 ·4H 2 O under solvothermal conditions to obtain an example of a 34-nucleus crown-shaped dysprosium cluster [Dy 34 (L) 8 (μ 2 -OH)(μ 3 -OH) 21 (μ 3 -O) 14 (OAc) 31 (OCH 3 ) 2 (H 2 O) 15 ](OAc) 3 ( 1 ). Structural analysis showed that the bisacylhydrazone ligand H 2 L 1 with polydentate chelate coordination sites could rapidly capture Dy III ions, thereby forming 34-nucleus crown-shaped dysprosium cluster 1 following the out-to-in growth mechanism. Cluster 1 remained stable after immersion in solutions with different pH values (3-14) for 24 h. To the best of the authors' knowledge, high-nucleation lanthanoid clusters with excellent strong acid and base stability and water stability are very rare. Meanwhile, high-resolution electrospray mass spectrometry molecular ion peaks produced by cluster 1 were captured, which proved to be stable also in organic solvents. Magnetic research showed that cluster 1 exhibited frequency-dependent behavior. This work provides a new idea for designing and synthesizing high-nucleation lanthanoid clusters with high stability.