Temperature-Responsive Self-Assembly of Single Polyoxometalates Clusters Driven by Hydrogen Bonds

Smart materials that can respond to external stimuli are typically prepared through the coating of specific responsive ligands. Herein, for the first time, thermally reconfigurable single polyoxometalate (POM) cluster assemblies without temperature-responsive surfactants are reported. Based on transmission electron microscopy observation, POM clusters are obtained to arrange into a 2D single cluster superlattice at 25 degrees C, and transform themselves into a single cluster nanowire below 0 degrees C, which is caused by the switching of hydrogen bond linkage between clusters. Contributed by the specific coordinative state, the POM assembly exhibits excellent catalytic activity and stability toward olefin epoxidation at room temperature, demonstrating the application potentials of the nanostructures based on single clusters.