Recent advances in polyoxometalate-based single-molecule magnets

Single-molecule magnets (SMMs) have attracted increasing attention in recent years due to the potentially applicable in high-density information storage and spintronic devices. There are now many high-performance SMMs that have been achieved by the use of organic ligands. Meanwhile, polyoxometalates (POMs) as inorganic multidentate ligands are toward prospective candidates for the fabrication of SMMs, owing to their oxygen-rich surfaces and various coordination geometries of the incorporated 3d- and 4f-ions. Notably, the bulky diamagnetic shell of POMs efficiently excludes dipole–dipole coupling between neighboring molecules, and the rigid frameworks offer the advantage for surface deposition and device applications. Hence, the wide variety of paramagnetic cations have been stabilized by POM ligands to establish SMMs, including mono-, di-, multi- and hetero-metal containing POMs. We herein systematically summarize the research progress achieved for POM-based SMMs reported in the last decade. The present review focuses on the design strategies for the construction of the SMMs referring to POM ligands and multifunctional properties of the POM-based SMMs for future application devices. This review provides a roadmap for the further exploration of compelling and challenging areas in POM-based SMMs.