Nanoclusters as precursors to (MoVW) ₅ O ₁₄ : In situ and chemical characterisation of the systems of a single phase oxidation catalyst

The ternary oxide (MoVW)5O14 is considered to be highly significant for catalytic, mild selective oxidation reactions. By using UV/Vis, EPR,95Mo NMR spectroscopies and conductivity measurements the coordination chemistry of the molybdate species in the precursor solutions was studied. This work has established that mixing the precursor solutions (ammonium heptamolybdate, ammonium metatungstate and vanadyl oxalate) forms a polymeric network in which the vanadyl species act as a linker between the molybdate species. The addition of tungsten atoms significantly enhances the polymerisation process.