Asymmetrically functionalized Anderson-type polyoxometalates were overviewed, including the key factors of various synthesis methods, separation methods, advantages of asymmetric structures, and their applications.
Anderson-type polyoxometalates (POMs) are one of the most important and widely developed groups of the POM family. The covalent functionalization of Anderson POMs has attracted extensive attention and facilitated broad applications of the resultant POM hybrids in catalysis, biology, energy materials and medicine. Among the various synthetic methods for Anderson hybrids, asymmetric functionalization has been one of the hottest and unique topics in the last decade. In the structure of asymmetric Anderson hybrids, two different organic components are anchored onto each side of the Anderson cluster or only one side of the cluster is functionalized. Asymmetric functionalization provides complexity to POM assemblies and merges multiple functions into one hybrid molecule, meanwhile, bringing challenges of rational design and controllable synthetic strategies. In this review, the latest progress in the synthetic methods and applications of asymmetrically functionalized Anderson-type POMs is summarized according to the central heteroatom of the cluster, which includes Mn-, Cr-, Al- and other metal-templated Anderson POMs.