Cobalt ethylenediaminetetraacetate

The reactivity of metals in Reactions 11 and 12 can be influenced by the gegenion or by complexing agents (26-29). Generally, coordinated metals are less reactive. Thus, the cobaltic ethylenediaminetetraacetic acid complex is not reduced by hydroperoxides (30), although cobaltic carboxylates are reduced very rapidly (28, 31). Coordination of metallic catalysts has been generally employed for their deactivation (32). On the other hand, researchers (10) have reported that the coordination of tran-... 

Nitrite administration has been augmented by thiosulfate administration (intravenously) in the treatment of cyanide poisoning. Cobalt-containing compounds (e.g., cobalt chloride and cobalt ethylenediaminetetraacetate) have also been used to form complexes with cyanide, in... 

Chromium (ITT) can be analy2ed to a lower limit of 5 x 10 ° M by luminol—hydrogen peroxide without separating from other metals. Ethylenediaminetetraacetic acid (EDTA) is added to deactivate most interferences. Chromium (ITT) itself is deactivated slowly by complexation with EDTA measurement of the sample after Cr(III) deactivation is complete provides a blank which can be subtracted to eliminate interference from such ions as iron(II), inon(III), and cobalt(II), which are not sufficiently deactivated by EDTA (275). 

The heavy metals copper, manganese, cobalt and zinc were omitted individually and in combination from MS and B5 media to determine the effect on antibody stability in solution [63]. When IgG, antibody was added to these modified media in experiments similar to the one represented in Figure 2.2, only the B5 medium without Mn showed a significant improvement in antibody retention relative to normal culture media. Nevertheless, protein losses were considerable as only about 30% of the added antibody could be detected in the Mn-free medium after about 5 h. The beneficial effect of removing Mn was lost when all four heavy metals, Cu, Mn, Co and Zn, were omitted simultaneously. The reason for these results is unclear. Addition of the metal chelating agent ethylenediaminetetraacetate (EDTA) had a negligible effect on antibody retention in both MS and B5 media [63]. 

Numerous d cobalt(III) complexes are known and have been studied extensively. Most of these complexes are octahedral in shape. Tetrahedral, planar and square antiprismatic complexes of cobalt(lII) are also known, but there are very few. The most common ligands are ammonia, ethylenediamine and water. Halide ions, nitro (NO2) groups, hydroxide (OH ), cyanide (CN ), and isothiocyanate (NCS ) ions also form Co(lII) complexes readily. Numerous complexes have been synthesized with several other ions and neutral molecular hgands, including carbonate, oxalate, trifluoroacetate and neutral ligands, such as pyridine, acetylacetone, ethylenediaminetetraacetic acid (EDTA), dimethylformamide, tetrahydrofuran, and trialkyl or arylphosphines. Also, several polynuclear bridging complexes of amido (NHO, imido (NH ), hydroxo (OH ), and peroxo (02 ) functional groups are known. Some typical Co(lll) complexes are tabulated below ... 

Ethylenediaminetetraacetic acid, analogs, complexes of, 3 277 chelation by, 3 276-277 cobalt complex of, 3 281 complexes, 3 277-278 formation constant of, 3 273-274 -nickel, 3 17-18 stability of, 3 266-267 reaction with metal ions, 3 62 Ethylene dibromide, irradiation of, 5 196 4,5-Ethylenedithio-1,3-dithiole-2-thione based supramolecular complexes, 46 200-204 Ethylene glycol, 32 4... 

A Mb reconstituted with cobalt(II) protoporphyrin IX was found to play a role as a catalyst for the photoinduced hydrogenation of acetylene when eosin is linked on the surface of the protein as shown in Fig. 24 (91). Irradiation of the eosin-linked cobalt Mb was found to produce a cobalt(I) species due to electron transfer from the photoexcited eosin moiety to cobalt(II) in the protein. In an aqueous solution, the cobalt(I) species is converted into cobalt(III)-hydride and the intermediate may react with acetylene in the presence of Na2edta [edta = ethylenediaminetetraacetic acid (ligand)] as a radical scavenger to... 

EDTA (ethylenediaminetetraacetic acid) forms stable metal chelates with a number of metal ions. Using this reagent as a complexing- agent, arsenic, bismuth, and selenium can be determined without any interference in the presence of nickel and cobalt. The cobalt-EDTA chelate is stable in 5 M HCl solution, whereas the corresponding bismuth complex is not. The influence of copper on the determination of arsenic can also be eliminated with EDTA, but not in the determination of selenium. Thiourea has been used to eliminate the influence of copper in the determination of antimony and sodium oxalate to eliminate the influence of copper and nickel in the determination of tin. An addition of thiosemicarbazide and 1,10-phenanthro-line reduces the interference of copper, nickel, platinum, and palladium in the determination of arsenic. 

A Figure 23.12 The complex ion [Co(EDTA)] . The ligand is the polydentate ethylenediaminetetraacetate ion, whose full representation is given in Table 23,2. This representation shows how the two N and four 0 donor atoms coordinate to cobalt. 

The chromatographic behaviour of ethylenediaminetetraacetate complexes of cobalt(II), nickel(II), copper(II), chromium(III), iron(III), cobalt(III) and bismuth(III) on Sephadex columns has been investigated by Deguchi [ref. 68]. 

Recently the chelating agent ethylenediaminetetraacetic acid (EDTA) has been used in connection with this problem,and although the relationships are complex, it is possible to show biological activity for Ca++ and Co++. Slater has used 8-hydroxyquinaline to remove trace elements from the basal medium and has demonstrated a cobalt requirement in glucose-free medium. No such requirement was found, however, when glucose was present. 

Cl H24CO2N2O14, Tetraaquocobalt(II) (ethylenediaminetetraacetato(4-))cobaltate(II) dihydrate, 44B, 1008 Cl Hj4N2O14Zn2, Zinc ethylenediaminetetraacetate hexahydrate, 39B, 789... 

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