1. Reaction of a copper-dioxygen complex with nitrogen monoxide (*NO) leads to a copper(II)-peroxynitrite species.
- Author
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Maiti D, Lee DH, Narducci Sarjeant AA, Pau MY, Solomon EI, Gaoutchenova K, Sundermeyer J, and Karlin KD
- Subjects
- Cations, Divalent, Electron Spin Resonance Spectroscopy, Oxygen chemistry, Spectrometry, Mass, Electrospray Ionization, Copper chemistry, Nitric Oxide chemistry, Organometallic Compounds chemistry, Peroxynitrous Acid chemistry
- Abstract
A discrete peroxynitrite-copper(II) complex, [(TMG3tren)CuII(-OONO)]+ (3), has been generated in solution (ESI-MS, m/z = 565.15; tetragonal EPR) by reacting *NO(g) with superoxo complex [(TMG3tren)CuII(O2*-)]+ (2). Complex 3 undergoes a thermal transformation to give CuII-nitrite complex [(TMG3tren)CuII(-ONO)]+ (4) (X-ray) along with ca. 0.5 molar equiv dioxygen. A DFT calculation derived structure with cyclic bidentate k2-O,O'-OONO bound peroxynitrite moiety and dx2-y2 ground state is proposed. Experiments using 18O2 suggest that the adjacent peroxo oxygen atoms in 3 are derived from molecular oxygen. Further, 18O2 containing 3 undergoes O-O bond cleavage to form singly 18-O-labeled 4. The results suggest the viability of biological CuI/O2/(*NO) peroxynitrite formation and chemistry, that is, not coming from free superoxide plus *NO reaction.
- Published
- 2008
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