Polyoxo Anions: Synthesis and Structure

Abstract A summary of the vast field of discrete polyoxometalate anions, which has until recently, predominantly been defined by heteropoly- and isopolymolybdates and -tungstates, and to a lesser extent, -vanadates. Unexpected developments in recent years have included the recognition of (a) a more extensive range of polyoxoniobates with an accessible alkaline solution chemistry, (b) polyoxoanions of d 8 metal centers, especially palladium(II), based on assemblies of square-planar MO 4 building units and (c) an extensive set of polyoxo(uranyl) and related actinyl clusters.