Synthesis, characterization, and reactivity of vanadium(V) complexes containing coordinated peroxide and histidine-A model for the active site of enzyme bromoperoxidase

Abstract

Vanadium(V) complexes of the type A[VO(O₂)₂(Hist)] (A=H⁺ or NH<img src='http://www.niscair.res.in/jinfo/plusfour.gif' border=0>; Hist=histidine) and [DmpzH][VO(O₂)₂(Dmpz)](Dmpz=3,5-dimethylpyrazole) have been synthesized from the reactions of V₂O₅ or NH₄ VO₃ with H₂O₂ in the presence of histidine or 3,5-dimethylpyrazole. The complexes have been characterised by elemental analyses, IR, ¹H, ¹³C and ⁵¹V NMR and electronic spectroscopic studies. Histidine has been shown to coordinate to vanadium centre through its imidazole nitrogen. Bromination of acetanilide by H[VO(O₂)(Hist)] and oxidising capability of [DmpzH][VO(O₂)₂(Dmpz)] are also reported.