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Of Fe EDTA

Iron(II) ediylenediaminetetraacetic acid [15651 -72-6] Fe(EDTA) or A/,Ar-l,2-ethaiiediylbis[A[-(carboxymethyl)glyciQato]ferrate(2—), is a colorless, air-sensitive anion. It is a good reducing agent, having E° = —0.1171, and has been used as a probe of outer sphere electron-transfer mechanisms. It can be prepared by addition of an equivalent amount of the disodium salt, Na2H2EDTA, to a solution of iron(II) in hydrochloric acid. Diammonium [56174-59-5] and disodium [14729-89-6] salts of Fe(EDTA) 2— are known. [Pg.439]

The BiodeNOx process is a novel process concept to reduce NO emissions from flue gases of stationary sources like power plants and other industrial activities [1]. The concept combines a wet chemicd absorption process with a novel biotechnological regeneration method. In the wet chemical absorption step, flue gas components are absorbed into an aqueous solution of Fe"(EDTA) (EDTA= ethylme-diamino-tetraacetic acid). The following reactions take place ... [Pg.793]

The experimental results imply that the main reaction (eq. 1) is an equilibrium reaction and first order in nitrogen monoxide and iron chelate. The equilibrium constants at various temperatures were determined by modeling the experimental NO absorption profile using the penetration theory for mass transfer. Parameter estimation using well established numerical methods (Newton-Raphson) allowed detrxmination of the equilibrium constant (Fig. 1) as well as the ratio of the diffusion coefficients of Fe"(EDTA) andNO[3]. [Pg.794]

As the radical tends to disproportionate, the rate of dissolution gradually decreases. Addition of EDTA to the system greatly enhances the dissolution owing to the formation of Fe -EDTA which dissolves the oxide via a thermal pathway. In the presence of 2-propanol, the Fe -EDTA is continually regenerated and thus acts as a catalyst. Similar behaviour has been observed for magnetite particles (Segal Sellers, 1984). [Pg.316]

Haber-Weiss reaction Hyaluronate of the bovine vitreous body was similarly protected by (Cu,Zn)-SOD, by catalase, and by peroxidase. The degradation of hyaluronate in the presence of ascorbate or of Fe cations was not inhibited by (Cu,Zn)-SOD The formation of OH radicals from H O and ascorbate, in the presence of traces of Fe-EDTA, was largely independent of superoxide radicals... [Pg.16]

Figure 12-8 Seven-coordinate geometry of Fe(EDTA)(H20). Other metal ions that form seven-coordinate EDTA complexes include Fe2. Mg2, Cd2, Co2. Mn2, Ru3, Cr3+. Co3, V3, Ti3+, In3, Sn4, Os4, and Ti4. Some of these same ions also form six-coordinate EDTA complexes. Eight-coordinate complexes are formed by Ca2, Er3 , Yb3r, and Zr4. p Mizuta. Figure 12-8 Seven-coordinate geometry of Fe(EDTA)(H20). Other metal ions that form seven-coordinate EDTA complexes include Fe2. Mg2, Cd2, Co2. Mn2, Ru3, Cr3+. Co3, V3, Ti3+, In3, Sn4, Os4, and Ti4. Some of these same ions also form six-coordinate EDTA complexes. Eight-coordinate complexes are formed by Ca2, Er3 , Yb3r, and Zr4. p Mizuta.
Bull C, McClune GJ, Fee JA (1983) The mechanism of Fe-EDTA catalyzed superoxide dismutation. J Am Chem Soc 105 5290-5300... [Pg.186]

Xue, H.-B., Sigg, L. and Kari, F.G. (1995) Speciation of EDTA in natural waters exchange kinetics of Fe-EDTA in river water. Environ. Sci. TechnoL, 29, 59-68. [Pg.235]

Kurimura et al. (22) studied the oxidation of Fe +(EDTA) and Fe +(NTA) by dissolved oxygen in aqueous solutions and suggested that the oxidation proceeds by two parallel reaction paths, with both pro-tonated and unprotonated chelates reacting. The reaction mechanisms suggested (22,23) are as follows ... [Pg.174]

Reduction of Ferric Chelates by HSO3 and Formation of Dithionate. FeJ+(EDTA) is reduced by HSO3, producing dithionate and a small amount of S0/2 (24). The rate of reduction of Fe +(EDTA) is first order in [HSO3] and [Fe +(EDTA)], and inversely first order in [Fe2+(EDTA)]. [Pg.175]

In the cases of Fe (EDTA) and Fe (TPP), the peroxide products (Fe (EDTA)(02 ) and Fen (TPP)(02 ) ) were believed to result from an outer-sphere electron transfer from the metal to Oi - with subsequent coordination of the oxidized metal by 02 . However, the reduction of 02 -to naked 2 requires an exceptionally strong reducing agent (e.g. sodium metal), and is precluded for Fe (EDTA) and Fe (TPP). [Pg.3486]

The sites of production of peroxynitrite are more likely to lie in closer proximity to the site of superoxide production as the latter is limited to transfer across the plasma membrane via anion channels, and has a shorter half-life (see above) [18]. It decomposes spontaneously at physiological pH, a process facilitated by the presence of Fe-EDTA and SOD, to yield nitrate (-65%) and nitrogen dioxide and the hydroxyl radical (-35%). Peroxynitrite is not a radical per se, and is less reactive than its protonated form. The pKa of the protonation reaction is 6.8, hence this proceeds efficiently at physiological pH yielding the potent oxidising species, peroxynitrous acid, which correspondingly decomposes to form the hydroxyl radical and nitrogen dioxide shown in Eq. 10 [27] ... [Pg.40]

Reaction of superoxide with a reduced metal-ion complex to give oxidation of the complex and release of hydrogen peroxide (analogous to Reaction 5.97) has been observed in the reaction of Fe EDTA with superoxide. Reduction of a Co superoxo complex by free superoxide to give a peroxo complex (analogous to Reaction 5.99) has also been observed. ... [Pg.300]

An illustration of DNA strand cleavage mediated by hydroxyl radicals produced by the Fenton reaction (A) of Fe(EDTA) with hydrogen peroxide. The cleavage scheme (B) shows the products obtained as a result of initial C4 -Fl abstraction by the hydroxyl radicals. [Pg.463]

Figure 10. Schematic and densitometric traces illustrating the effects of Fe(EDTA) - mediated OH- attack on different types of DNA. Densitometric traces obtained after cleaving with Fe(EDTA) " (left) B-DNA (center) bent DNA and (right) DNA bound on one face of CaSO< crystals (35). Figure 10. Schematic and densitometric traces illustrating the effects of Fe(EDTA) - mediated OH- attack on different types of DNA. Densitometric traces obtained after cleaving with Fe(EDTA) " (left) B-DNA (center) bent DNA and (right) DNA bound on one face of CaSO< crystals (35).
Comparison of Fe complexes of edta and cydta reveals that deprotonation of coordinated water in Fe-cydta takes place two pH units above that of Fe-edta and the dimerization constant Ad is two units lower for Fe-cydta. Table II gives a summary of the protolytic properties of various Fe " " complexes. Fe pdta (pdta=l,2 propanediaminetetraacetate) with an intermediate backbone rigidity is included to gain a deeper understanding of the protolytic properties. [Pg.150]

Scheme 5. Scheme of equilibria connected with the formation of the ternary fluoride, nitrosyl, and dioxygen complexes of [Fe (edta)(H20)]... [Pg.161]

In order to clarify the nature of the reaction product, detailed IR and N-labeled NMR experiments were performed, from which it was concluded that the nitrosyl product can formally be described as a Ru -NO complex. Note that in the case of NO binding to [Fe edta)(H20)] , the nitrosyl product was found to be a Fe -NO species (58,59). Detailed kinetic studies using sf and fp experiments (65) confirmed the very rapid binding constant reported before (66). In addition, NO trapping experiment using [Fe (edta)(H20)] showed that it was impossible to remove the coordinated NO from [Ru (edta)(NO )], even in the presence of a very large excess of [Fe (edta)(H20)] , which demonstrated the very efficient binding of NO to [Ru (edta)(H20)] . [Pg.164]


See other pages where Of Fe EDTA is mentioned: [Pg.439]    [Pg.106]    [Pg.476]    [Pg.181]    [Pg.439]    [Pg.174]    [Pg.410]    [Pg.413]    [Pg.3197]    [Pg.140]    [Pg.339]    [Pg.489]    [Pg.83]    [Pg.264]    [Pg.3196]    [Pg.208]    [Pg.320]    [Pg.452]    [Pg.568]    [Pg.145]    [Pg.148]    [Pg.160]    [Pg.160]    [Pg.167]    [Pg.168]    [Pg.168]    [Pg.174]    [Pg.178]    [Pg.416]   
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