Chelates nickel

Nickel halide complexes with amines give mixtures of linear polymer and cychc trimers (30). Nickel chelates give up to 40% of linear polymer (31). When heated with ammonia over cadmium calcium phosphate catalysts, propargyl alcohol gives a mixture of pyridines (32). 

Nickel dialkyldithiocarbamates stabili2e vulcani2ates of epichlorhydrinethylene oxide against heat aging (178). Nickel dibutyldithiocarbamate [56377-13-0] is used as an oxidation inhibitor in synthetic elastomers. Nickel chelates of substituted acetylacetonates are flame retardants for epoxy resins (179). Nickel dicycloalkyldithiophosphinates have been proposed as flame-retardant additives for polystyrene (180—182) (see Flame retardants Heat stabilizers). 

The stability constant for the nickel chelate of pyrido[2,3-d]-pyrimidine-4(3 r)-one has been measured. ... 

Hydrogen reduction of nickel alkyl, Ni(C5H5)2 at 200°C, or nickel chelate, Ni(C5HFg02)2 at 250°C. 

It can also be deposited by the hydrogen reduction of the nickel chelate, Ni(C5HFg02)2 at 250°C.P 1 In addition to thermal processing reviewed above, nickel is deposited by laser C VD from the carbonyl with a krypton or a pulsed CO2 laser.P lP l... 

Dordick, 1991). In addition, Fancy et al. (1996) as well as Fancy and Kodadek (1997, 1998) have applied the oxidation of tyrosine to form dityrosine to the study of protein-protein interactions using nickel-chelated 6 X His tagged fusion proteins in oxidative environments. 

One limitation to this method should be noted. If the antibody-enzyme conjugate is prepared using antibody fragments such as Fab or F(ab )2, then nickel-chelate affinity chromatography will not work, since the requisite Fc portion of the antibody necessary for complexing with the metal is not present. 

Figure 20.15 An affinity chromatography support containing iminodiacetic acid groups chelated with nickel may be used to remove excess enzyme after reactions to produce antibody-enzyme conjugates. The nickel chelate binds to the antibody in the Fc region, retaining the conjugate while allowing free enzyme to pass through the gel unretarded.

Zero-valent nickel-chelating phosphine complexes are used at 120°C under C02 pressure. 

Nickel catalysts, 77 94, 99, 109 precipitated, 77 121-122 Nickel-catalyzed dinitrotoluene hydrogenation, 25 194 Nickel chelates, 77 117 Nickel chloride hexahydrate, 77 109, 110 Nickel chromate, molecular formula, properties, and uses, 6 562t Nickel-chromium alloy 600, in galvanic series, 7 805t... 

Nickel-chelating resins IgG Sepharose 6 Fast Flow Chelating Sepharose Fast Flow ... 

The first observation of an abnormal magnetic moment, in the sense intended here, was made by French et al. (90), who found that the normally diamagnetic bis(formylcamphor)ethylenedi-imine nickel(II) had a magnetic moment of 1.9 B.M. in methanol. They suggested that a fraction of the complex molecules were fully paramagnetic in the solution, an idea which is still universally accepted. Willis and Mellor (261) developed this theme and found that the phenomenon covered a wide range of nickel chelates and also of solvents. The moments developed were larger in pyridine than in inert solvents like benzene or chloroform, and the moments in pyridine often corresponded to complete conversion into para-... 

Axial perturbation may be taken to indicate the presence of negative charge on the 2-axis, which means that there must be atoms there. From the chemist s point of view it is interesting to know what sort of atoms lie on the axis, and whether they should be regarded as coordinated to the metal or not. Maki (161) proposed that, in solutions of these nickel chelates, all molecules are equally solvated, and that the difference between pyridine and inert solvents is only one of degree. In the melts there must then be some sort of molecular interaction, which does not have more than a minimal effect on the viscosity (222) the melts can be regarded as auto-solutions (221). 

In view of the inherent properties of the system, many attempts have been made to extend the shade range commercially but with little success. An example is the purple nickel chelate (65) derived from dimethylmaleic anhydride (B-71MI11207). 

The azomethine dye (102) (76BRP1451000) and the nickel chelates (103) and (104) have also been claimed to have activity in protecting image dyes from degradation by light (79BRP2022U9, 80BRP2026518). 

In the tunicates (sea squirts and their relatives) it occurs in a fixed ratio with cobalt, suggesting a metabolic role.460 A new class of nickel chelates called tunichlorins have been isolated. An example is shown in Fig. 16-27B. The function of tunichlorins is unknown but their existence suggests the possibility of unidentified biochemical roles for nickel. 

The nickel chelate with dithiooxalate anion (S Oi-, dto) is much more stable than that with the oxygen analogue. K2Ni(dto)2 has been obtained in two polymorphic forms. A dark-red... 

If two cations are present together, the one forming the more stable complex will generally precipitate at a lower pH, for differences in stability are usually more significant than differences in solubility. Anomalous and overriding solubility effects such as those noted with the copper and nickel chelates of DMG (see Section 10.2.1.2) are the exception rather than the rule.19 Under... 

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