Oxidation - reduction properties

Redox Potentials of the Electron Accepting Sites in Ceruloplasmin 

Attempts to correlate changes in 330 nm absorbance with equihbrium redox potentials were iminformative 123). Nemst Plots yielded m-values ranging from 

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Table 6.2 Apparent formal redox potentials of systems present in the electron-transfer chain (pH = 7). It should be noted that the potential values were obtained in the homogeneous phase. Due to stabilization in a membrane, the oxidation-reduction properties vary so that the data listed below are of orientation character...

J.A. Fee and P.E. DiCorleto, Oxidation-reduction properties of bovine erythrocyte superoxide dismutase. Biochemistry. 12, 4893-4899 (1973). 

Cross, A. R., Harper, A. M., Segal, A. W. (1981). Oxidation-reduction properties of the cytochrome b found in the plasma-membrane fraction of human neutrophils. Biochem. J. 194, 599-606. 

Volt-equivalent diagrams convey the same amount of information as do Latimer diagrams about the relative stabilities of the oxidation states of an element and their oxidation/reduction properties, but do it in a graphical manner. Such diagrams are given in subsequent chapters for selected elements to illustrate further the differences in potentials between successive oxidation states. 

Riboflavin (vitamin B2) 6,7-dimethyl-9-(D-l-ribityl)isoalloxazine (63), was discovered as a coloring matter in milk in 1879, but its importance was not then realized. Deficiency causes lesions of the eye and of the angle of the mouth. Riboflavin is phosphorylated by adenosine triphosphate (ATP) to give riboflavin 5 -phosphate (flavinadenine mononucleotide, FMN) and then flavinadenine dinucleotide (FAD) (64 R = riboflavin). These function as prosthetic groups in a number of flavoproteins which are dehydrogenation catalysts by virtue of the oxidation-reduction properties of the isoalloxazine system. 

Morss, L.R. 1994. Comparative thermochemical and oxidation-reduction properties of lanthanides and actinides. In Handbook on the Physics and Chemistry of Rare Earths, eds. K.A. Gschneider, J.L. Eyring, G.R. Choppin, G.H. Lander, pp. 239-257. Elsevier Science B.V., Amsterdam. 

N. A. Strombaugh, J. E. Sundquist, R. H. Burris, and W. H. Orme-Johnson, Oxidation-Reduction Properties of Several Low Potential Iron-Sulfur Proteins of Methylviologen. Biochem., 15, 2533 2641 (1976). 

The effect of additives in altering the catalyst environment has been studied by Wright and Weller (6). Chelation is known to alter the oxidation-reduction properties of ions and therefore could be expected to alter the activation of hydrogen. Ethylene diamine and ethylene diamine tetra-acetic acid inhibit both the rate and extent of reduction of quinone and cupric acetate monohydrate in quinoline solution at 100°. The production of metallic copper is related to the presence of organic material. 

Therefore, having considered the experimental material published on this reaction, we seen no reason to assume any mechanism other than the well established Haber-Weiss mechanism, which requires a catalyst of the right oxidation/ reduction properties. 

L.R. Morss, Comparative thermochemical and oxidation - reduction properties of lanthanides and actinides 239... 

The investigation of the oxidation-reduction properties of heteropoly compounds of molybdenum in aqueous and nonaqueous solvents has received increasing attention in recent years. Such knowledge may not only elucidate the redox behavior of such compounds but it could help in the investigation of new preparative procedures for... 

The iron-sulfur cubes that have been detected by x-ray analysis (49) as constituents of the enzymes ferridoxin and high-potential iron protein have been extruded from these enzymes by replacing the sulf-hydryl ligands of the enzymes with simple mercaptans, and these cubes identified with the corresponding synthetic compounds, II (50, 51, 52, 53). The latter have oxidation-reduction properties that closely mimic those of the enzymes. Similarly, an iron-sulfur-molybdenum double cube has been ejected from nitrogenase, and a similar double cube has been synthesized by Holm and his collaborators (54). It remains to be seen whether or not the iron-sulfur-molybdenum double cube can mimic the properties of nitrogenase (55). 

Farhangrazi ZS, Copeland BR, Nakayama T et al (1994) Oxidation-reduction properties of compounds I and II of Arthromyces ramosus peroxidase. Biochemistry 33 5647-5652... 

Newton, W. E., Schultz, F. A., Gheller, S. F., Lough, S., McDonald, J. W., Conradson, S. D., Hedman, B., Hodgson, K. O. (1986), Iron-molybdenum cofactor of Azotobacter vinelandii nitrogenase oxidation-reduction properties and structural insights. Polyhedron 5, 567-72. 

Silver halide microcrystals are wide band gap semiconductors which exhibit weak photoconductivity. Early experiments demonstrated that dyes that sensitized silver halide photographic action also sensitized silver halide photoconductivity [6c]. Since the observation of photoconductivity necessitates the movement of free charge within the crystals, dye sensitization processes must inject charge into the silver halide lattice in some way. Initial theories of sensitization were based on the semiconductor view of silver halides, especially as espoused by Gurney and Mott [10]. Current ideas are based on thorough studies of the absorption spectroscopy and luminescence of silver halide emulsions and of adsorbed, sensitizing dyes, and the oxidation-reduction properties of the dyes at silver/silver halide electrodes [11]. 

On the basis of temperature programmed reduction and oxidation (TPR-TPO) measurements, it was proposed that the calcination of chromia used as a catalyst for the selective fluorination of CF3CH2C1 into CF3CH2F depends strongly on the gas used to calcine the precursor [50], Furthermore, the fluorination of CF3CH2C1 depends directly on the number of reversibly oxidizible chromium atoms in the catalysts. The oxidation/reduction properties are related closely to the atmosphere of pre-treatment and a linear relationship between the catalytic activity and the hydrogen uptake during the second reduction step has been found [51],... 

Pace, C. P., and Stankovich, M. T., 1991, Oxidation-reduction properties of trimethylamine dehydrogenase effect of inhibitor binding. Arch. Biochem. Biophys. 287 9711104. 

Fig. 2. Oxidation-reduction properties of the FeMo-cofactor. M(ox), M(s-r), and M(r) represent the oxidized, semireduced (dithionite isolated form), and reduced form, respectively, of the protein-bound FeMo-cofactor (49).

Fig. 3. Oxidation-reduction properties of the P-cluster pair. P represents the form of the P-cluster pair found in dithionite isolated MoFe-protein, whereas P represents more oxidized forms of the center (65).

Compounds with oxidation reduction properties (oxides, sulphurs) to determine the accessible surface. 

The gas phase reaction proceeds very much as described for nickel carbonyl, but the product does not contain the nitrite group (10). A smoke is formed immediately the gases come into contact, but the analysis and infrared spectrum of the solid formed show it to be the oxide-nitrate Fe0(N03). It seems likely that initial reaction involves the NO2 radical, and an iron nitrite such as Fe(N02)3 may be produced initially. The oxidation-reduction properties of the ferric and nitrite ions may render them incompatible Fe0(N03) would then be left as a decomposition product. So little is known about transition metal nitrites that this must remain conjecture at present, but it may be relevant to recall that it has not yet been possible to isolate pure samples of Fe(N03)3, A1(N03)3, or Cr(N03)3. 

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