Different anion (NO and OAc)-controlled construction of dysprosium clusters with different shapes

The complex hydrolysis process and strong uncertainty of self-assembly rules have led to the precise synthesis of lanthanide clusters still being in the "blind-box" stage and simplifying the self-assembly process and developing reliable regulation strategies have attracted widespread attention. Herein, different anions are used to induce the construction of a series of dysprosium clusters with different shapes and connections. When the selected anion is NO 3 − , it blocks the coordination of metal sites around the cluster through the terminal group coordination mode, thereby controlling the growth of the cluster. When NO 3 − was changed to OAc − , OAc − adopted a bridging mode to induce modular units to build dysprosium clusters through an annular growth mechanism. Specifically, we selected 2-amino-6-methoxybenzoic acid, 2-hydroxybenzaldehyde, and Dy(NO 3 ) 3 ·6H 2 O to react under solvothermal conditions to obtain a pentanuclear dysprosium cluster ( 1 ). The five Dy( iii ) ions in 1 are distributed in upper and lower planes and are formed by the tight connection of nitrogen and oxygen atoms, and μ 3 -OH − bridges on the ligand. Next, octa-nuclear dysprosium cluster ( 2 ) were obtained by only regulating ligand substituents. The eight Dy( iii ) ions in 2 are tightly connected through ligand oxygen atoms, μ 2 -OH − , and μ 3 -OH − bridges, forming an elliptical {Dy/O} cluster core. Furthermore, only by changing NO 3 − to OAc − , a wheel-shaped tetradeca-nuclear dysprosium cluster ( 3 ) was obtained. Cluster 3 is composed of OAc − bridged multiple template Dy 3 L 3 units and pulling of these template units connected by an annular growth mechanism forms a wheel-shaped cluster. The angle of the coordination site on NO 3 − is ∠ONO = 115°, which leads to the further extension of the metal sites on the periphery of clusters 1 and 2 through the terminal group coordination mode, thereby regulating the structural connection of the clusters. However, the angle of the coordination site on OAc − is ∠OCO = 128°, and a slightly increased angle leads to the formation of a ring-shaped cluster 3 by connecting the template units through bridging. This is a rare example of the controllable construction of lanthanide clusters with different shapes induced by the regulation of different anions, which provides a new method for the precise construction of lanthanide clusters with special shapes. Slightly different anions were used to induce the construction of a series of lanthan