Microwave Synthesis of Alkali‐Free Hexaniobate, Decaniobate, and Hexatantalate Polyoxometalate Ions

Microwave preparation of polyoxoniobates and ‐tantalates afford a more rapid alternative to conventional hydrothermal methods of synthesis, in addition to allowing for the use of anhydrous niobium pentoxide in lieu of niobic acid, albeit with diminished yields. Limitations associated with the pH at which different oxides can be activated and how this affects the accessibility of different products are also discussed.