Lanthanopolyoxometalates: From the structure of polyanions to the design of functional materials

The ability of polyoxometalates (POMs) to behave as inorganic ligands capable of coordinating to lanthanide ions has received extraordinary scientific interest, leading to the preparation and characterization of a wide diversity of POMs containing lanthanides, herein designated as lanthanopolyoxometalates (LnPOMs). The cooperative combination of the lanthanide cations and POMs characteristics and properties originate novel compounds with notable structural features and remarkable potential applications in various technological areas, such as catalysis, optical/magnetic sensors and medical imaging. The main LnPOM anions have been isolated by the coordination of lanthanide centers in vacant sites of the archetypal POM structures (Lindqvist-, Keggin-, Wells–Dawson-, Preyssler-type, and others) and are briefly reviewed in the first part of this research report. The most important structural features and prominent properties of selected LnPOMs are described. The second part of the research report, focuses on the utilization of coordination LnPOM anions for the preparation of functional materials and devices. Several examples of support compounds (surfactants, nanostructured thin films, nanoparticles, mesoporous silicates, layered double hydroxides and metal–organic frameworks) incorporating, encapsulating and/or supporting LnPOMs to prepare composite materials are reviewed.