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      https://www.ias.ac.in/article/fulltext/jcsc/102/03/0365-0377

    • Keywords

       

      Peroxo-metal and non-metal compounds; reactivity in aqueous media; substitute for the basic-H2O2 reagent

    • Abstract

       

      Newer reactions of coordinated peroxide at metal and non-metal centres are described. Reactions of peroxo-metal complexes with SO2(g), NO2(g), and CO2(g) have been carried out in aqueous medium. Typically, reactions of a highly peroxygenated metal complex, A[V(O2)3]·3H2O (A=Na,K), follow an unprecedented sequence. The deep blue ESR-silent solution of A[V(O2)3]·3H2O reacts to produce a yellow, ESR-inactive solution that on further reaction with the chosen substrate affords a green-blue ESR-active (cf. VO2+) solution. The reaction proceeds through distinct steps such that, first, one of the coordinated peroxides undergoes a two-electron irreversible cleavage of the O-O bond leading to a diperoxy-mono(sulphato)vanadate(V) intermediate, [(O2)2V-O-SO3], that readily undergoes hydrolysis to produce H2SO4 and an aquaoxo-diperoxovanadate(V) complex, [VO(O2)2H2O]. The latter complex reacts with more SO2(g) causing reduction of vanadium (V) to vanadium (IV) and conversion of coordinated peroxide to coordinated sulphate producing the bis(sulphato)vanadyl complex, [VO(SO2)2(H2O)2]2−.

      Further, the reaction of A[V(O2)3]·3H2O with SO2(g) in the presence of AF, yielding a ternary fluoro(sulphato)oxovanadate (IV) complex A4[VO(SO4)2F2(H2O)]·2H2O, serves as a paradigm for the synthesis of ternary complexes of vanadyl, VO2+. It is also evidentinteralia that the [V(O2)3] species offers potential as a novel synthon.

      Some recent developments in the peroxo-chemistry of B, C, P and As are highlighted. Heretofore unreported salts of peroxo phosphoric acid, viz. (NH4)3[PO3(O2)]·3H2O and Na3[PO3(O2)]·3H2O, have been synthesized and their potential as oxidants explored. Their role in oxidising organic substances is highlighted, especially as a substitute for the alkaline-H2O2 reagent.

    • Author Affiliations

       

      Manish Bhattacharjee1 Mihir K Chaudhuri1 Nashreen S Islam1

      1. Department of Chemistry, North-Eastern Hill University, Shillong - 793003, India
    • Dates

       
  • Journal of Chemical Sciences | News

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