Hydrolysis-Promoted Building Block Assembly: Structure Transformation from Y Wheel and Y Ship to Y Cage

Accurately controlling the hydrolysis of metal ions can not only yield the desired structure of metal hydroxide clusters but also provide a deeper understanding of the formation process of natural hydroxide minerals. However, the capture of hydrolysis intermediates remains a significant challenge, and metal hydroxide clusters are mainly obtained by employing adventitious hydrolysis. In this study, we realized a hierarchical building block assembly from Y³⁺ ions to large Y, Y, and Y clusters by controlling the hydrolysis process of lanthanide ions under different pH conditions. Single-crystal structural analysis showed that the Y wheel, Y ship, and Y sodalite cage contain 4, 12, and 24 cubane-like [Y₄(μ₃-OH)₄]⁸⁺ units, respectively. The structure of the Y cluster can be attributed to two Y clusters or six Y clusters linked by vertices. These clusters can be synthesized through the hydrolysis of Y³⁺ under different pH conditions, and Y can be prepared from the obtained Y or Y crystals by the simple addition of Y³⁺ ions. The capture and conversion of the intermediates of lanthanide series hydroxide clusters, Y or Y, during the assembly from Y³⁺ ions to Y can facilitate an understanding of the formation process of high-nuclearity lanthanide clusters.