The oxygenase activity of natural metallo-enzymes offers a unique paradigm of what is the Holy Grail of oxidation chemistry. An innovative approach to the design of oxygenase functional mimics is the adoption of a totally inorganic ligand system derived from polyoxometalates (POMs), as an alternative to organic or organometallic coordination complexes. Bio-inspired activity of transition- metal-substituted POMs (TMSP, with TM being Fe, Mn, Ru) has been proposed in the recent literature. However, due to the severe mechanistic complexity, which is frequently associated with metal-mediated aerobic oxidations, it is a major challenge to unravel the catalyst’s role along oxygen-transfer pathways. Therefore, in the realm of POM-based oxygenase mimics, the adherence to bio-inspired mechanistic features is often a matter of debate and retains a fundamental interest.

catalysisAmong the class of Fesubstituted polyoxotungstates some structural types are known, where the coordination geometry of the iron center exhibits a striking oxygenase synzyme motif. In particular, the tetrasubstituted Krebs-type polyanions with general formula [Fe4(H2O)10(β-XW9O33)2]n- (Fe4X2W18, X=AsIII, SbIII ; n=6; X=SeIV, TeIV; n=4), display two of the four iron sites with three terminal, substitution-labile coordination positions, typical of non-heme dioxygenase enzymes. The latter are responsible for the catabolism/ biodegradation of dihydroxylated aromatic compounds. While several functional models have been designed with coordination complexes using polydentate organic ligands, very few examples deal with POM-based systems, and FeIII framework-incorporated POMs as multi-turnover catalysts for the aerobic cleavage of catechols are unprecedented.

Selected Publications

  • Photo-assisted water oxidation by high-nuclearity cobalt-oxo cores: tracing the catalyst fate during oxygen evolution turnover
    Natali, M.; Bazzan, I.; Goberna-Ferrón, S.; Al-Oweini, R.; Ibrahim, M.; Bassil, B. S.; Dau, H.; Scandola, F.; Galán-Mascarós, J. R.; Kortz, U.; Sartorel, A.; Zaharieva, I.; Bonchio, M.  Green Chemistry  2017, 19, 2416-2426. [Read Online]
  • Photocatalytic Water Oxidation by a Mixed-Valent MnIII3MnIVO3 Manganese-Oxo-Core that Mimicks the Natural Oxygen Evolving Center
    Al-Oweini, R.; Sartorel, A.; Bassil, B. S.; Natali, M.; Berardi, S.; Scandola, F.; Kortz, U.; Bonchio, M. Angew. Chem. Int. Ed. 2014, 53, 11182-11185. [Read Online]
  • A Lewis Acid Catalytic Core Sandwiched by Inorganic Polyoxoanion Caps: Selective H2O2-based Oxidations with [AlIII4(H2O)10(β-XW9O33H)2]6- (X = AsIII, SbIII)
    Carraro, M.; Bassil, B. S.; Sorarù, A.; Berardi, S.; Suchopar, A.; Kortz, U.; Bonchio, M. Chem. Commun. 201349, 7914-7916. [Read Online]
  • DENDRI-POM Hybrids Based on Keggin, Dawson, Preyssler and Venturello Polyanions and Their Catalytic Evaluation in Oxidation Reactions
    Jahier, C.; Mal, S. S.; Al-Oweini, R.; Kortz, U.; Nlate, S. Polyhedron 201357, 57-63. [Read Online]
  • Palladium (0) metal clusters: Novel Krebs type polyoxoanions stabilized, extremely active hydrogenation catalyst
    D’Souza, L.; Noeske, M.; Richards, R. M.; Kortz, U. Applied Catalysis A: General 2013453, 262-271. [Read Online]
  • Reactive ZrIV and HfIV Butterfly Peroxides on Polyoxometalate Surfaces: Bridging the gap between Homogeneous and Heterogenous Catalysis
    Carraro, M.; Nsouli, N. H.; Oelrich, H.; Sartorel, A.; Sorarù, A.; Mal, S. S.; Scorrano, G.; Walder, L.; Kortz, U.; Bonchio, M. Chem. Eur. J. 2011, 17, 8371-8378. [Read Online]
  • Epoxidation of Alkenes with H2O2 Catalyzed by di-Titanium-Containing 19-Tungstodiarsenate(III): Experimental and Theoretical studies
    Donoeva, B. G.; Trubitsina, T. A.; Antonova, N. S.; Carbó, J. J.; Poblet, J. M.; Al-Kadamany, G.; Kortz, U.; Kholdeeva, O. A. Eur. J. Inorg. Chem. 2010, 5312-5317. [Read Online]
  • Hexazirconium- and Hexahafnium-Containing Tungstoarsenates(III) and Their Oxidation Catalysis Properties
    Al-Kadamany, G.; Mal, S. S.; Milev, B.; Donoeva, B.; Maksimovskaya, R.; Kholdeeva, O. A.; Kortz, U. Chem. Eur. J. 2010, 16, 11797-11800. [Read Online]
  • Mechanistic Insights into Alkene Epoxidation with H2O2 by Ti- and other TM-containing Polyoxometalates: Role of the Metal Nature and Coordination Environment
    Antonova, N. S.; Carbó, J. J.; Kortz, U.; Kholdeeva, O. A.; Poblet, J. M. J. Am. Chem. Soc. 2010, 132, 7488-7497. [Read Online]
  • Dendritic Zirconium-Peroxo Tungstosilicate Hybrids: Synthesis, Characterization and Use as Recoverable and Reusable Sulfide Oxidation Catalysts
    Jahier, C.; Mal, S. S.; Kortz, U.; Nlate, S. Eur. J. Inorg. Chem. 2010, 10, 1559-1566. [Read Online]
  • Peroxo-Zr/Hf Containing Undecatungstosilicates and -Germanates
    Mal, S. S.; Nsouli, N. H.; Carraro, M.; Sartorel, A.; Scorrano, G.; Oelrich, H.; Walder, L.; Bonchio, M.; Kortz, U. Inorg. Chem. 2010, 49, 7-9. [Read Online]
  • Organo-Ruthenium Supported Heteropolytungstates: Synthesis, Structure, Electrochemistry and Oxidation Catalysis
    Bi, L.-H.; Al-Kadamany, G.; Chubarova, E. V.; Dickman, M. H.; Chen, L.; Gopala, D. S.; Richards, R. M.; Keita, B.; Nadjo, L.; Jaensch, H.; Mathys, G.; Kortz, U. Inorg. Chem. 2009, 48, 10068-10077. [Read Online]
  • Unique Catalytic Performance of the Polyoxometalate [Ti2(OH)2As2W19O67(H2O)]8-: The Role of 5-Coordinated Titanium in H2O2 Activation
    Kholdeeva, O. A.; Donoeva, B. G.; Trubitsina, T. A.; Al-Kadamany, G.; Kortz, U. Eur. J. Inorg. Chem. 2009, 5134-5141. [Read Online]
  • Iron Substituted Polyoxotungstates as Inorganic Synzymes: Evidence for a Biomimetic Pathway in the Catalytic Oxygenation of Catechols
    Sartorel, A.; Carraro, M.; Scorrano, G.; Bassil, B. S.; Dickman, M. H.; Keita, B.; Nadjo, L.; Kortz, U.; Bonchio, M., Chem. Eur. J 2009, 15, 7854-7858. (“Dedicated to the Centenary of the Italian Chemical Society”) [Read Online]
  • Heterogeneous wheel shaped Cu20-tungstophosphate ([Cu20Cl(OH)24(H2O)12(P8W48O184])25-) catalyst for solvent-free aerobic oxidation of n-hexadecane
    Chen, L.; Hu, J.; Mal, S. S.; Kortz, U.; Jaensch, H.; Mathys, G.; Richards, R. M. Chem. Eur. J. 2009, 15, 7490-7497. [Read Online]
  • Solvent-Free Aerobic Oxidation of n-Alkane by Iron(III)-Substituted Polyoxotungstates Immobilized on SBA-15
    Chen, L.; Zhu, K.; Bi, L.H.; Suchopar, A.; Reicke, M.; Mathys, G.; Jaensch, H.; Kortz, U.; Richards, R. M. Inorg. Chem., 2007, 46, 8457-8459. [Read Online]
  • Di-Titanium Containing 19-Tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8-: Synthesis, Structure, Electrochemistry and Oxidation Catalysis
    Hussain, F.; Bassil, B. S.; Kortz, U.; Kholdeeva, O. A.; Timofeeva, M. N.; de Oliveira, P.; Keita, B.; Nadjo, L. Chem. Eur. J., 2007, 13, 4733-4742. [Read Online]
  • Aerobic oxidation of cis-cyclooctene by iron-substituted polyoxotungstates: Evidence for a metal initiated auto-oxidation mechanism
    Bonchio, M.; Carraro, M.; Farinazzo, A.; Sartorel, A.; Scorrano, G.; Kortz, U. J. Mol. Cat. A: Chem., 2007, 262, 36-40. [Read Online]

» Complete List of Publications