Hydrogen chelated

Fe304 + Fe + 8H+ + 4chelant > 4Fe(ll)chelant + 4H20 magnetite steel hydrogen chelated iron water... 

Abstract—The spectroscopic phenomena of strong hydrogen bonds (band shifts, band broadening, intensity increase) are attributed to the interaction of the n electrons with the hydrogen atom, using the latter s distorted p-orbit. The analogy of the spectra phenomena in the hydrogen-chelated and metal-chelated coinpounds is stressed. 

E. Further thoughts on Hydrogen-Chelates, and a Very Short 0 Bond that is Unsymmetrical... 

Examples of very short hydrogen bonds that are not S3mimetrical are of special interest. We have already given one example in Sect. XIX. Another is the cation represented in (26) whose structure (in the hydrated chloride) has been determined by X-ray (99) and subsequently be neutron-diffraction analysis (700). This cation is a hydrogen-chelate, like the hydrogen-maleate anion, and the hydrogen bond is similarly short ... 

The fact that (II) is formed only in neutral or basic solution but not in mineral acid solution may be explained as follows The dye acid underlying (I) contains the group A in the nonreactive hydrogen chelate form A which in its turn is in a pH-dependent equilibrium with the reactive anion A Accordingly, an adequate quantity of A" ions is obtained from this... 

Tautomerism and dynamics of hydrogen chelates were investigated in the quinazoline-2-acetonitrile series (Scheme 5.24) [63]. Equilibria are fast on the NMR... 

Some examples of the use of a temporary additional site of coordination have been published. Burk and Feaster have transformed a series of ketones into hydrazones capable of chelating to a rhodium catalyst (Scheme 4.7). Upon coordination, enanti os elective hydrogenation of the hydrazone is feasible, yielding N-aroylhydrazines in up to 97% ee. Finally, the hydrazines were transformed into amines by treatment with Sml2. 

In the most common method for chemiluminescent immunoassay (GLIA), after the immunological reaction and any necessary separation steps, the labeled compounds or complexes react with an oxidizer, eg, hydrogen peroxide, and an enzyme, eg, peroxidase, or a chelating agent such as hemin or metal... 

EDTA (ethylenediaminetetraacetic acid, [60-00-4]) chelates any trace metals that would otherwise decompose the hydrogen peroxide [7722-84-1]. The amine is preheated to 55—65°C and the hydrogen peroxide is added over one hour with agitation the temperature is maintained between 60 —70°C. The reaction is exothermic and cooling must be appHed to maintain the temperature below 70°C. After all the peroxide has been added, the temperature of the reaction mixture is raised to 75°C and held there from three to four hours until the unreacted amine is less than 2.0%. The solution is cooled and the unreacted hydrogen peroxide can be destroyed by addition of a stoichiometric amount of sodium bisulfite. This may not be desirable if a low colored product is desired, ia which case residual amounts of hydrogen peroxide enhance long-term color stabiUty. 

NKK s Bio-SR process is another iron-based redox process which instead of chelates, uses Thiobacillusferroidans )2iQ. - 2i to regenerate the solution (9). This process absorbs hydrogen sulfide from a gas stream into a ferric sulfate solution. The solution reacts with the hydrogen sulfide to produce elemental sulfur and ferrous sulfate. The sulfur is separated via mechanical means, such as filtering. The solution is regenerated to the active ferric form by the bacteria. 

Chelating agents that are polybasic acids give two or more hydrogen ions per molecule. The four stages of dissociation of EDTA, eg, are represented by the equations... 

In both cases n is the number of hydrogen ions displaced in the formation of the complex. In solutions where the ratio of free chelating agent to complex, ], is held constant, the slopes of the curves pM vs pH are equal. o n m. the region where H A is the principal form of the chelating... 

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