Tungsten Peroxopolyoxo Complexes as Advanced Catalysts for the Oxidation of Organic Compounds with Hydrogen Peroxide

Selective oxidation of organic substrates by environment-friendly oxidizing agents is an important ingredient of the sustainable chemical industry. Here we report a comprehensive study in the field of metal peoroxocomplex catalysis for the selective liquid phase oxidation of various organic substrates. A number of well-defined bifunctional tungsten complex catalysts with tetra nuclear structure {PO4[WO(O-2)(2)](4) }(3-) in combination with a phase-transfer agents were synthesized. The structural properties were thoroughly studied using of IR, Raman and EXAFS spectroscopy. By combining different spectroscopy techniques were able to elucidate the effect of quaternary ammonium cations on the structural properties of the resulting peroxo complexes. The catalytic properties of these well-defined material were then evaluated in bi-phasic selective oxidation of cyclooctene, methyl oleate and N-phosphonomethyliminodiacetic acid with hydrogen peroxide under mild conditions. For every substrate we were able to achieve high conversion at the selectivity towards a target product close to 100%.