Metals complexation agents for

Metal Complexing Agents for the Treatment of Alzheimer s Disease... 

Wallace EM, Yeh TC, Laird ER, Blake JF, Lyssikatos J (2007) Inhibition of Growth Factor Signaling by Small-Molecule Inhibitors of ErbB, Raf, and MEK. 1 65-114 White AR, Bush AI (2007) Metal Complexing Agents for the Treatment of Alzheimer s Disease. 2 107-136... 

Direct Titrations. The most convenient and simplest manner is the measured addition of a standard chelon solution to the sample solution (brought to the proper conditions of pH, buffer, etc.) until the metal ion is stoichiometrically chelated. Auxiliary complexing agents such as citrate, tartrate, or triethanolamine are added, if necessary, to prevent the precipitation of metal hydroxides or basic salts at the optimum pH for titration. Eor example, tartrate is added in the direct titration of lead. If a pH range of 9 to 10 is suitable, a buffer of ammonia and ammonium chloride is often added in relatively concentrated form, both to adjust the pH and to supply ammonia as an auxiliary complexing agent for those metal ions which form ammine complexes. A few metals, notably iron(III), bismuth, and thorium, are titrated in acid solution. 

Acetone cyanohydrin is used as a raw material for insecticides manufacture and also to produce ethyl a-hydroxyisobutryate [80-55-7], a pharmaceutical intermediate. It has been used as a complexing agent for metals refining and separation. Acetone cyanohydrin complexes can be used to separate, Cu , , 7x5, Cd , or Fe from Mg , , Ca , Na , or on strongly basic ion-exchange resins (31). Acetone cyanohydrin is... 

The heavy metals, copper, chromium, mercury, nickel, and 2inc, which are used as catalysts and complexing agents for the synthesis of dyes and dye intermediates, are considered priority poUutants (313). 

Many crown ethers synthesized by C. J. Pederson (Nobel Prize for Chemistry, 1987) who also studied their use as complexing agents for alkali metal and other cations. 

Schuster, M. Selective complexing agents for the trace enrichment of platinum metals. Fresenius J. Anal. Chem. 1992, 342, 791-794. 

Used industrially in organic synthesis, in the manufacture of insecticides and pharmaceuticals, as an intermediate in the synthesis of methacrylates used as a complexing agent for metals refining and separation. 

Chlorine is the major anion in surface- and mantle-derived fluids. It is the most abundant anion in hydrothermal solutions and is the dominant metal complexing agent in ore forming environments (Banks et al. 2000). Despite its variable occurrence, chlorine isotope variations in natural waters conunonly are small and close to the chlorine isotope composition of the ocean. This is also true for chlorine from fluid inclusions in hydrothermal minerals which indicate no significant differences between different types of ore deposits such as Mississippi-Valley and Porphyry Copper type deposits (Eastoe et al. 1989 Eastoe and Guilbert 1992). 

The bipyridines are dibasic, and the two acid dissociation constants Ki and K2, for all the bipyridines have been determined. Typical values are recorded in Table I. There has been considerable interest in the first dissociation constants Ki of 2,2 -bipyridine and substituted 2,2 -bipyridines because of their use as metal complexing agents. In general, the order of relative basic strengths of derivatives of 2,2 -bipyridine is as expected. Electron-attracting substituents reduce the basicity, whereas electron-donating substituents increase the basicity of the molecule. " The dissociation constants of several substituted bipyridines correlate well with the Hammet equation. 2,2 -Bipyridines with an electron-donating substituent at position 4 are monoprotonated at N-1 and not at... 

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