Related Experiment Video
Updated: Jun 27, 2026
14:44
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Heme-copper assembly mediated reductive coupling of nitrogen monoxide (*NO)
Jun Wang1, Mark P Schopfer, Amy A N Sarjeant
1Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Journal of the American Chemical Society
|December 23, 2008
Summary
This study demonstrates a novel iron-dinitrosyl complex that, with copper and acid, couples nitric oxide (NO) to form nitrous oxide (N2O). This system serves as a functional model for nitric oxide reductase enzymes.
Area of Science:
- Bioinorganic Chemistry
- Coordination Chemistry
- Enzyme Mimicry
Background:
- Nitric oxide (NO) plays crucial roles in biological systems.
- Nitric oxide reductase (NOR) enzymes are vital for denitrification pathways.
- Understanding the mechanisms of NO metabolism is essential for biological and chemical applications.
Purpose of the Study:
- To develop a functional model for heme/copper nitric oxide reductase activity.
- To investigate the mechanism of nitric oxide (NO) coupling and reduction.
- To explore the role of copper ions in NO transformation.
Main Methods:
- Synthesis of an iron-dinitrosyl complex ((6)L)Fe(NO)2.
- Investigated the reaction of the complex with copper(I) ions and acid.
- Utilized UV-vis spectroscopy to monitor reaction progress.
- Analyzed gaseous products, including nitrous oxide (N2O).
Main Results:
- The iron-dinitrosyl complex efficiently couples two NO molecules to release N2O in the presence of Cu+ and acid.
- Copper ion within the ligand framework is essential for NO coupling chemistry.
- A proposed mechanism involves copper(I)-promoted disproportionation of NO.
- The reaction yields a heme/copper product, [((6)L)Fe(III)...Cu(II)(D)]3+.
Conclusions:
- The described chemical system serves as a stoichiometric functional model for heme/copper nitric oxide reductase.
- This work provides insights into the catalytic mechanisms of NO reduction.
- Highlights the importance of metal-ligand cooperation in redox processes involving NO.
Related Concept Videos
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
02:36Oxymercuration-Reduction of Alkenes
Oxymercuration–reduction of alkenes is one of the major reactions converting alkenes to alcohols. It involves the hydration of alkenes with mercuric acetate in a mixture of tetrahydrofuran and water, forming an organomercury adduct. This is followed by a demercuration step in which the adduct is reduced to an alcohol using sodium borohydride.
00:55Nitriles to Amines: LiAlH4 Reduction
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...