Nitrite reduction by copper through ligand-mediated proton and electron transfer
Cameron M Moore1, Nathaniel K Szymczak1
1Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , MI 48109 , USA .
Chemical Science
|July 15, 2017
Summary
Copper complexes with proton-responsive ligands can reduce nitrite to nitric oxide. This process, mediated by the ligand, mirrors natural copper nitrite reductase activity.
Area of Science:
- Inorganic Chemistry
- Bioinorganic Chemistry
- Catalysis
Background:
- Nitrite reduction is a key biological process.
- Copper complexes are investigated for catalytic applications.
- Proton-responsive ligands offer tunable reactivity.
Purpose of the Study:
- To demonstrate nitrite reduction using a copper complex with a proton-responsive tripodal ligand.
- To identify the by-products of the reduction reaction.
- To elucidate the mechanism of nitrite reduction.
Main Methods:
- Synthesis and characterization of a copper complex with a tripodal ligand.
- Nitrite reduction experiments under controlled conditions.
- Gas chromatography-mass spectrometry (GC-MS) for by-product analysis.
- Density Functional Theory (DFT) calculations for mechanistic insights.
Main Results:
- The copper complex effectively reduces nitrite.
- Gaseous nitric oxide (NO) was the sole by-product, obtained in quantitative yield.
- DFT calculations suggest a proton-electron transfer mechanism mediated by the ligand.
Conclusions:
- The studied copper complex catalyzes nitrite reduction.
- The mechanism involves ligand-mediated proton and electron transfer.
- This system provides a biomimetic model for copper nitrite reductase.
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