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Angewandte Chemie (International Ed. in... 2009Complex electron transfer reactions have been characterized whereby in addition to electron transfer, subsequent electrochemical, chemical and even in some cases... (Review)
Review
Complex electron transfer reactions have been characterized whereby in addition to electron transfer, subsequent electrochemical, chemical and even in some cases biological consequences occur. These include a secondary electron transfer that leads to a major rearrangement of the electronic structure, such that an initial oxidation leads to a reduction (or an initial reduction leads to an oxidation) for these valence ambiguous compounds. Mixed valency and valence-tautomeric behaviors can additionally result from these complex electron-transfer-induced reactions.
Topics: Electron Transport; Ligands; Molecular Structure; Organometallic Compounds; Oxidation-Reduction; Stereoisomerism
PubMed: 18972460
DOI: 10.1002/anie.200705138 -
Chemical Reviews Oct 2011
Review
Topics: Free Radicals; Lipid Peroxidation; Oxidation-Reduction
PubMed: 21861450
DOI: 10.1021/cr200084z -
Environmental Health Perspectives Feb 1995Several metal or metalloid ions exist in multiple oxidation states and can undergo electron transfer reactions that are important in biological and environmental...
Several metal or metalloid ions exist in multiple oxidation states and can undergo electron transfer reactions that are important in biological and environmental systems. There are endogenous metal ions such as iron, copper, and cobalt that participate in oxidation-reduction reactions with species of oxygen like molecular dioxygen, superoxide, and hydrogen peroxide. These reactions may be modulated by endogenous reducing agents such as glutathione, ascorbate, and tocopherol. The reactions can be described in terms of thermodynamics through the use of standard electrode potentials. A favorable reaction will depend on the concentrations of the reactants and may depend on the pH and/or on the presence of organic ligands that form complexes with the metal or metalloid. Arsenate (As(V)) can react with glutathione in buffered aqueous solutions to produce arsenite (As(III)) and oxidized glutathione. This reaction may be important in the methylation reactions of arsenic. Arsenic species can decrease the red blood cell levels of reduced glutathione, but the products of oxidation and the mechanism of oxidation are more complex than those found in water alone. Chromium (VI) is thought to interact with DNA after first reacting with a reducing agent such as glutathione to form lower oxidation states of chromium. These examples illustrate the importance of oxidation-reduction reactions for toxic metals and metalloids.
Topics: Carcinogens, Environmental; Electron Transport; Humans; Hydrogen-Ion Concentration; Ions; Metals; Oxidation-Reduction; Potentiometry; Reference Standards
PubMed: 7621791
DOI: 10.1289/ehp.95103s117 -
Postepy Higieny I Medycyny... 1964
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Revue International Des Services de... 1958
Topics: Anesthesiology; Oxidation-Reduction
PubMed: 13579723
DOI: No ID Found -
Annual Review of Biochemistry 1947
Topics: Antioxidants; Oxidation-Reduction
PubMed: 20259061
DOI: 10.1146/annurev.bi.16.070147.001141 -
Nature Mar 1946
Topics: Oxidation-Reduction
PubMed: 21019859
DOI: 10.1038/157340a0 -
Advances in Inorganic Biochemistry 1988
Review
Topics: Cytochrome c Group; Electron Transport; Kinetics; Oxidation-Reduction
PubMed: 2821745
DOI: No ID Found -
Harvey Lectures
Topics: Oxidation-Reduction; Oxidative Phosphorylation
PubMed: 13232547
DOI: No ID Found -
The Analyst Aug 2016The reduction and oxidation of the flavin system is an important electron transfer reaction in biological systems. Several reaction pathways exist to connect oxidized to...
The reduction and oxidation of the flavin system is an important electron transfer reaction in biological systems. Several reaction pathways exist to connect oxidized to fully reduced riboflavin, each with unique intermediates including a semi-quinone radical. By performing surface-enhanced Raman scattering (SERS) with simultaneous electrochemical detection of riboflavin at different pH values, we are able to correlate reversible changes in spectral features to the current changes observed in the cyclic voltammetry. Multivariate curve resolution analysis of the SERS spectra indicates that three distinct components were present at the SERS electrode at each pH during the potential sweep. To verify and better understand the variations in Raman bands across the voltammogram, density functional theory (DFT) calculations were performed to model the effect of pH and oxidation state on the riboflavin Raman spectrum. The calculated spectra show qualitative agreement with the species identified in the chemometric analysis. This combination of results indicates the presence of the oxidized, semi-quinone, and reduced forms of riboflavin and provides insight into the mechanism of the flavin redox system.
Topics: Electrodes; Electron Transport; Oxidation-Reduction; Riboflavin; Spectrum Analysis, Raman
PubMed: 27297697
DOI: 10.1039/c6an01054g