Utilizing Single-Crystalline Transformations for Precise Atom Placement in Multicomponent Cluster-Based Coordination Networks

The controlled integration of multiple components remains a significant challenge in the design of complex materials. Here, we present a strategy for synthesizing polyoxometalate (POM)-based coordination networks with up to three different cations in precisely defined positions. Our approach leverages a single-crystal-to-single-crystal transformation in which the spatial placement cations is governed by their availability at distinct stages of crystallization and transformation. Specifically, [ZP5W30O110](15−n)− (Z = Na+, K+, Ca2+, Ag+, Bi3+, Y3+, any Ln3+, Th4+) is coordinatively assembled with various bridging metal cations (Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+, Th4+). Using the encapsulated cation (Z) to label the POM, we track structural changes during the transformation, confirming the single-crystalline nature. Understanding this transformation pathway allows for rational control over the placement of different cations. These findings establish a versatile strategy for constructing multicomponent materials with exceptional compositional and spatial precision.