Macromolecular peroxo complexes of Vanadium(V) and Molybdenum(VI): Catalytic activities and biochemical relevance

Abstract

Our recent achievements concerning the synthesis and characterization of water soluble peroxo complexes of V(V) and Mo(VI) in macroligand environment, as well as some key features of biological relevance of these compounds, such as their hydrolytic stability, activity with phosphohydrolase enzyme vis-à-vis free peroxovanadium (pV) or peroxomolybdenum (pMo) complexes, and their activity in biomimetic oxidative bromination are presented here. Immobilization of pMo species on insoluble polymer matrices viz., amino acid functionalized Merrifield resins and poly(acrylonitrile) on the other hand, afforded a set of heterogeneous catalysts highly effective in facile organic transformations such as selective oxidation of organic sulfides and oxidative bromination of aromatic substrates by H2O2, at ambient temperature. The methodologies are straightforward, high-yielding, halogen-free and the catalysts afford easy regeneration. Our findings illustrate the various features which make the procedures sustainable and synthetically useful. Series of macrocomplexes have been synthesized by immobilizing peroxo species of vanadium and molybdenum on water soluble, as well as insoluble polymer supports. The soluble complexes inhibit the activity of phosphatases non-competitively. The insoluble polymeric complexes served as efficient heterogeneous catalysts for selective organic oxidations under eco-compatible reaction conditions.