Synthesis and characterization of novel polyoxometalates with an inverted-Keggin structure as a new class of building unit

Novel polyoxometalates with an inverted-Keggin structure were prepared and isolated as the tetra-alkylammonium salts from an aqueous organic solution. They were characterized using elemental analysis, X-ray analysis, UV–vis, IR and Raman spectroscopy. This study demonstrates that these novel polyoxometalates with an inverted-Keggin structure could be used as a new building block material because they have both a carboxy group and an alkene part, which could react with other organic substrates.