Anderson-Type Polyoxometalate-Based Covalent Organic Frameworks

Anderson-type polyoxometalates (Anderson POMs) are a distinctive subclass of POMs characterized by a planar disk-like geometry, moderate molecular dimensions, tunable central heteroatoms, and bilateral organic modification sites. These features endow them with high structural programmability; however, the high aqueous solubility, aggregation tendency, and limited accessible surface area of discrete clusters hinder their effective utilization. Covalent organic frameworks (COFs), featuring crystalline porosity, large surface areas, ordered channels, and designable frameworks, provide an ideal platform for immobilizing, confining, and functionally amplifying Anderson POMs. The resulting Anderson POM-based COFs integrate molecular redox/catalytic sites with accessible pore environments, delivering enhanced stability, efficient mass/charge transport, and tunable host-guest interactions. This review summarizes recent advances in Anderson POM-based COFs, emphasizing how cluster geometry, linkage modes, and spatial distribution determine framework functionality. Three construction strategies, in-situ synthesis, post-synthetic modification, and electrostatic assembly, are discussed, followed by applications in energy storage, catalysis, adsorption, and sensing. Finally, key challenges in structural determination, stability, mechanistic understanding, and scalable fabrication are critically assessed, and future perspectives for the rational design of Anderson POM-based COFs are outlined.