Direct Resonance Raman Characterization of a Peroxynitrito Copper Complex Generated from O2 and NO and Mechanistic Insights into Metal-Mediated Peroxynitrite Decomposition

Angew Chem Int Ed Engl. 2019 Aug 5;58(32):10936-10940. doi: 10.1002/anie.201904672. Epub 2019 Jul 3.

Abstract

We report the formation of a new copper peroxynitrite (PN) complex [CuII (TMG3 tren)(κ1 -OONO)]+ (PN1) from the reaction of [CuII (TMG3 tren)(O2.- )]+ (1) with NO.(g) at -125 °C. The first resonance Raman spectroscopic characterization of such a metal-bound PN moiety supports a cis κ1 -(- OONO) geometry. PN1 transforms thermally into an isomeric form (PN2) with κ2 -O,O'-(- OONO) coordination, which undergoes O-O bond homolysis to generate a putative cupryl (LCuII -O. ) intermediate and NO2. . These transient species do not recombine to give a nitrato (NO3- ) product but instead proceed to effect oxidative chemistry and formation of a CuII -nitrito (NO2- ) complex (2).

Keywords: Raman spectroscopy; bioinorganic chemistry; copper; nitrogen oxides; peroxynitrite.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coordination Complexes / chemical synthesis*
  • Coordination Complexes / chemistry
  • Copper / chemistry*
  • Molecular Structure
  • Nitric Oxide / chemistry*
  • Oxygen / chemistry*
  • Peroxynitrous Acid / chemistry*
  • Spectrum Analysis, Raman

Substances

  • Coordination Complexes
  • Peroxynitrous Acid
  • Nitric Oxide
  • Copper
  • Oxygen