Reaction of a Copper−Dioxygen Complex with Nitrogen Monoxide (•NO) Leads to a Copper(II)−Peroxynitrite Species

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• 作者：Debabrata Maiti ; Dong-Heon Lee ; Amy A. Narducci Sarjeant ; Monita Y. M. Pau ; Edward I. Solomon ; Katya Gaoutchenova ; J&#xf6 ; rg Sundermeyer ; Kenneth D. Karlin
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：May 28, 2008
• 年：2008
• 卷：130
• 期：21
• 页码：6700 - 6701
• 全文大小：273K
• 年卷期：v.130,no.21(May 28, 2008)
• ISSN：1520-5126

文摘

A discrete peroxynitrite−copper(II) complex, [(TMG₃tren)Cu^II(⁻OONc="http://pubs.acs.org/images/entities/dbd_2.gif">O)]⁺ (3), has been generated in solution (ESI-MS, m/z = 565.15; tetragonal EPR) by reacting •NO_(g) with superoxo complex [(TMG₃tren)Cu^II(O₂^•−)]⁺ (2). Complex 3 undergoes a thermal transformation to give Cu^II−nitrite complex [(TMG₃tren)Cu^II(⁻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 d_x²−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 Cu^I/O₂/(•NO) peroxynitrite formation and chemistry, that is, not coming from free superoxide plus •NO reaction.