Molecular Catalysis of O2 Reduction by Iron Porphyrins in Water: Heterogeneous versus Homogeneous Pathways

2015 ◽  
Vol 137 (42) ◽  
pp. 13535-13544 ◽  
Author(s):  
Cyrille Costentin ◽  
Hachem Dridi ◽  
Jean-Michel Savéant
Keyword(s):  
Iron Porphyrins ◽  
O2 Reduction ◽  
Molecular Catalysis

scholarly journals Rational Design of Mononuclear Iron Porphyrins for Facile and Selective 4e–/4H+ O2 Reduction: Activation of O–O Bond by 2nd Sphere Hydrogen Bonding

2018 ◽  
Vol 140 (30) ◽  
pp. 9444-9457 ◽  
Author(s):  
Sarmistha Bhunia ◽  
Atanu Rana ◽  
Pronay Roy ◽  
Daniel J. Martin ◽  
Michael L. Pegis ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Rational Design ◽  
Iron Porphyrins ◽  
Mononuclear Iron ◽  
O2 Reduction

O2 Reduction by Iron Porphyrins with Electron Withdrawing Groups: To Scale or not to Scale

2021 ◽  
Author(s):  
Sk Amanullah ◽  
Paramita Saha ◽  
Abhishek Dey
Keyword(s):  
Iron Porphyrins ◽  
O2 Reduction ◽  
The Relationship

Iron porphyrins are synthesized by systematically introducing electron withdrawing groups (EWGs) on pyrroles to evaluate the relationship between rate (k) and overpotential (η). The results indicate that while EWGs lead...

scholarly journals Influence of the distal guanidine group on the rate and selectivity of O2 reduction by iron porphyrin

2019 ◽  
Vol 10 (42) ◽  
pp. 9692-9698 ◽  
Author(s):  
Arnab Ghatak ◽  
Snehadri Bhakta ◽  
Sarmistha Bhunia ◽  
Abhishek Dey
Keyword(s):  
Reduction Reaction ◽  
Iron Porphyrin ◽  
Iron Porphyrins ◽  
Guanidine Group ◽  
O2 Reduction

The O2 reduction reaction (ORR) catalysed by iron porphyrins with covalently attached pendant guanidine groups is reported.

A Revised O2 Reduction Model in Li-O2 Batteries as Revealed by in Situ Small Angle X-Ray Scattering

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Reduction Mechanism ◽  
Reduction Model ◽  
X Ray ◽  
X Ray Scattering ◽  
O2 Reduction ◽  
Ray Scattering

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

Oxygen-Oxygen Bond Cleavage and Formation in Co(II) Mediated Stoichiometric O2 Reduction via the Potential Intermediacy of a Co(IV) Oxyl Radical

2018 ◽  
Author(s):  
Lucie Nurdin ◽  
Denis M. Spasyuk ◽  
Laura Fairburn ◽  
Warren Piers ◽  
Laurent Maron
Keyword(s):  
Bond Cleavage ◽  
Peroxo Complex ◽  
Oxygen Oxygen ◽  
O2 Reduction ◽  
Oxygen Bond ◽  
Pentadentate Ligand

Diprotonation of a remarkably stable, toluene soluble cobalt peroxo complex supported by a neutral, dianionic pentadentate ligand leads to facile O-O bond cleavage and production of a highly reactive Co(IV) oxyl cation intermediate that dimerizes and releases O<sub>2</sub>. These processes are relevant to both O<sub>2</sub> reduction and O<sub>2</sub> evolution and the mechanism was probed in detail both experimentally and computationally.

Reductive Dehalogenation of Environmental Contaminants: A Critical Review

1989 ◽  
Vol 24 (2) ◽  
pp. 299-322 ◽  
Author(s):  
R. M. Baxter
Keyword(s):  
Hydrogen Atom ◽  
Aromatic Compounds ◽  
Reductive Dechlorination ◽  
Halogen Atom ◽  
Environmental Contaminants ◽  
Methanogenic Bacteria ◽  
Photochemical Reactions ◽  
Reductive Dehalogenation ◽  
Iron Porphyrins ◽  
Aliphatic Compounds

Abstract It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom. A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment. Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers. Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.

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