| 1. |
- Armstronga, D. A., et al.
(författare)
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Standard electrode potentials involving radicals in aqueous solution : Inorganic radicals
- 2013
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Ingår i: BioInorganic Reaction Mechanisms. - : Walter de Gruyter GmbH. - 2191-2491 .- 2191-2483. ; 9:1-4, s. 59-61
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Tidskriftsartikel (refereegranskat)abstract
- Inorganic radicals, such as superoxide and hydroxyl, play an important role in biology. Their tendency to oxidize or to reduce other compounds has been studied by pulse radiolysis; electrode potentials can be derived when equilibrium is established with a well-known reference compound. An IUPAC Task Group has evaluated the literature and produced the recommended standard electrode potentials for such couples as (O2/O2 ·-), (HO·, H+/H2O), (O3/O3 ·-), (Cl2/Cl2 ·-), (Br2 ·-/2Br-), (NO2 ·/NO2 -), and (CO3 ·-/CO3 2-).
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| 2. |
- Merkofer, M., et al.
(författare)
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Fenton chemistry and iron chelation under physiologically relevant conditions : Electrochemistry and kinetics
- 2006
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 19:10, s. 1263-1269
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Tidskriftsartikel (refereegranskat)abstract
- The goal of iron-chelation therapy is to reduce the levels of labile plasma iron, and intravenously administered desferrioxamine is the gold standard of therapeutic agents. Hydroxypyridinones, e.g., CP20 (3-hydroxy-1,2- dimethylpyridin-4(1H)-one), are used or are under investigation as orally administered iron chelators. We determined electrode potentials of CP20, the related hydoxypyridones CP361, CP363, and CP502, and ICL670 (4-[3,5-bis(2- hydroxyphenyl)-1H-1,2,4-triazol-1-yl]benzoic acid) under physiologically relevant conditions to address the question of whether iron in the presence of these chelating agents can carry out Fenton chemistry in vivo. We found that iron(III) but not iron(II) binds tightly to both CP20 and ICL670 at pH 7 and higher, compared to nearly complete binding of 1 µM iron(II) to 10 µM desferrioxamine at pH 7.4 The electrode potentials of the hydroxypyridinones shift to more negative values with decreasing pKa values at lower concentrations of iron(III) (0.02 mM) and ligand (0.1 mM). The electrode potential of the iron-CP20 system decreases as a function of increasing pH, with a minimum near pH 10.5. We estimate an electrode potential for the ascorbyl radical/ascorbate couple under physiological conditions of +105 mV, which is higher than the electrode potential of the iron(III) complex of CP20 at all concentrations of iron. The rate of oxidation of iron(II) in the presence of CP20 by hydrogen peroxide increases with the concentrations of both ligand and peroxide. Although iron(II) is oxidized by hydrogen peroxide, the thus-formed FeIII(CP20)3 complex cannot be reduced by ascorbate. Therefore, the tight binding of iron(III) by this class of chelators prevents redox cycling. © 2006 American Chemical Society.
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| 3. |
- Sargeson, A. M., et al.
(författare)
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Names and symbols for the transfermium elements
- 1997
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Ingår i: Pure and Applied Chemistry. - : Walter de Gruyter GmbH. - 0033-4545 .- 1365-3075. ; 69:12, s. 2471-2473
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Tidskriftsartikel (refereegranskat)abstract
- The recommendations (ref. 1) of the Commission on Nomenclature of Inorganic Chemistry (CNIC) on the nomenclature of the transfermium elements (101-109, inclusive) were considered by the IUPAC Bureau at Guildford (UK) in September 1995. As a result of the various criticisms of the recommendations and theway that they had been processed, the Bureau decided to adopt the recommendations as provisional and to circulate them to national/regional nomenclature centres in the normal way, with notices to be published innational/regional chemistry journals and magazines, requesting submission of comments to CNIC. In particular, the National Adhering Organizations (NAOs) were invited to express their views concerning the extant proposals for the names of these elements and the principles and traditions used to derive them. The response from the general chemical community was small, and the bulk of the replies came from nuclear scientists.
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| 4. |
- Sargeson, A. M., et al.
(författare)
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Names and symbols of transfermium elements (IUPAC recommendations 1994)
- 1994
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Ingår i: Pure and Applied Chemistry. - : Walter de Gruyter GmbH. - 0033-4545 .- 1365-3075. ; 66:12, s. 2419-2421
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Tidskriftsartikel (refereegranskat)abstract
- The Transfermium Working Group (TWG) was set up in 1986 under the joint auspices of the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP). Its conclusions, duly endorsed by IUPAC and IUPAP, were published in the following three reports:1. Criteria that must be satisfied for the discovery of a new chemical element to be recognized, Pure & Appl. Chem., 63, 879-886 (1991).2. Discovery of the transfermium elements: Introduction to the discovery profiles, Pure & Appl. Chem., 65, 1757-1763 (1993).3, Discovery of the transfermium elements: Discovery profiles of the transfermium elements, Pure & Appl. Chem., 65, 1764-1814 (1993).IUPAC went a stage further by inviting responses on reports 2 and 3 from the three major groups concerned, i.e., Lawrence Berkeley Laboratory, California; Joint Institute for Nuclear Research, Dubna; and Gesellschaft fur Schwerionenforschung , Darmstadt. These responses together with the TWG's reply to the responses were published unedited in Pure & Appl. Chem.,Vol. 65, (1993), pp. 1815-1824.
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