Reaction of a copper-dioxygen complex with nitrogen monoxide (*NO) leads to a copper(II)-peroxynitrite species.
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.
Maiti
Debabrata
D
Departments of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Lee
Dong-Heon
DH
Narducci Sarjeant
Amy A
AA
Pau
Monita Y M
MY
Solomon
Edward I
EI
Gaoutchenova
Katya
K
Sundermeyer
Jörg
J
Karlin
Kenneth D
KD
D002413:Cations, Divalent; D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D009569:Nitric Oxide / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D030421:Peroxynitrous Acid / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D002413:Cations, Divalent; D009942:Organometallic Compounds; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; D003300:Copper; D010100:Oxygen