Nickel appearance

A complex reaction takes place when dichlorobis(triphenylphosphine)-nickel (5) is treated with excess methylmagnesium bromide in ether. Detectable amounts of benzene, toluene, and biphenyl are formed, together with mixed phosphines. Nickel appears to be necessary for the substitution reaction since triphenylphosphine alone does not react with the Grignard reagent. 

Bruland et al. [122] have shown that seawater samples collected by a variety of clean sampling techniques yielded consistent results for copper, cadmium, zinc, and nickel, which implies that representative uncontaminated samples were obtained. A dithiocarbamate extraction method coupled with atomic absorption spectrometry and flameless graphite furnace electrothermal atomisation is described which is essentially 100% quantitative for each of the four metals studied, has lower blanks and detection Emits, and yields better precision than previously published techniques. A more precise and accurate determination of these metals in seawater at their natural ng/1 concentration levels is therefore possible. Samples analysed by this procedure and by concentration on Chelex 100 showed similar results for cadmium and zinc. Both copper and nickel appeared to be inefficiently removed from seawater by Chelex 100. Comparison of the organic extraction results with other pertinent investigations showed excellent agreement. 

Nickel ions have been shown to depress the in vivo and in vitro release of prolactin [336], while the release of growth hormone was stimulated, and only at relatively high ion concentrations. Hyperglycemia occurs in rats following intraperitoneal or intratracheal injections of NiCl2 [265, 337, 338], The mechanism of action of nickel appears to be inhibition of insulin release this inhibition could be related to the extremely high concentration of nickel found in the pituitary and the effect on the secretion of the pituitary hormones (growth hormone and adrenocorticotropic hormone). 

The next five transition metals iron, cobalt, nickel, copper and zinc are of undisputed importance in the living world, as we know it. The multiple roles that iron can play will be presented in more detail later in Chapter 13, but we can already point out that, with very few exceptions, iron is essential for almost all living organisms, most probably because of its role in forming the amino acid radicals required for the conversion of ribonucleotides to deoxyribonucleotides in the Fe-dependent ribonucleotide reductases. In those organisms, such as Lactobacilli6, which do not have access to iron, their ribonucleotide reductases use a cobalt-based cofactor, related to vitamin B12. Cobalt is also used in a number of other enzymes, some of which catalyse complex isomerization reactions. Like cobalt, nickel appears to be much more extensively utilized by anaerobic bacteria, in reactions involving chemicals such as CH4, CO and H2, the metabolism of which was important... 

Because of the high coke-forming tendencies of reduced crude, mainly due to a high concentration of Ramsbottom Carbon, the adverse effects of nickel appear to be somewhat moderated in the trip up the riser. Therefore, nickel does not appear to be quite as harmful as first anticipated. 

As indicated in Scheme 27, indoles may be alkylated by their acid-catalyzed reaction with alcohols. Similarly, r-butylation of pyrroles has been effected by the acid-catalyzed reaction with t- butyl acetate (B-77MI30502), and the diarylmethylation of 1-methylpyrrole from the acid-catalyzed reaction with the chromium trichloride complex of the diarylcarbinol has been described (78JA4124). The alkylation of indoles by alcohols in the presence of the aluminum alkoxide and Raney nickel appears to be efficient for the synthesis of 3-substituted indoles, but is less successful in the alkylation of 2-methylindole (79JHC501). The corresponding isopropylation of pyrrole produces 2,5-diisopropylpyrrole and 1-isopropylpyrrolidine, as the major products (79JHC501). 

The four types of nickel-containing enzymes are quite distinct in the coordination sites and catalytic function of the nickel centers. In urease, the nickel appears to be bound to oxygen and nitrogen ligands and appears to remain as Ni(II), a state which favors octahedral or square-planar coordination. The function of nickel in this unique case may be analogous to that of zinc in other hydrolases such as carboxypeptidase. 

During interaction of the diazonium chloride, and the o-ethyl dithiocarbonate ( xan-thate ) solutions, care must be taken to ensure that the intermediate diazonium dithiocarbonate decomposes to 2-thiocresol as fast as it is formed [1]. This can be assured by presence of a trace of nickel in the solution to effect immediate catalytic decomposition. When the 2 solutions were mixed cold and then heated to effect decomposition, a violent explosion occurred [2]. Caution The experiments claimed to show catalysis by nickel appear to have been performed on diazotised anthranilic acid which is the only benzenediazonium system never known to give explosive intermediates with sulfur nucleophiles [3]. 

The net charge on albumin appears to be more significant than the nature of the substrate when considering how much protein initially binds to the aqueous/solid interface. More protein adsorbed onto copper, nickel, and germanium substrates at pH 4.8, where albumin has no net surface charge, than at pH 4.0 or pH 7.4. Since no charge effects exist between the macromolecules adsorbed on the surface, high protein densities at the aqueous/solid interface would be expected. Copper and nickel appeared to accumulate the same quantities of albumin independent of the pH studied. 

A rough surface presents more surface area on which physical absorption can occur. More protein might have been expected to adsorb on the copper and nickel films as compared to germanium due to the granular nature of these films. Only at pH 7.4 did copper and nickel accumulate more albumin than did germanium, however. Despite the macroscopic differences in surface morphology copper and nickel appeared to accumulate the same quantity of albumin. 

Tetrakis[phosphorus(III) chloride] nickel is a pale yellow crystalline solid at room temperature and becomes colorless on cooling to about — 30°. This compound is stable in air when dry and unreactive with water at room temperature for a period of several days. It reacts slowly in the cold with dilute acids and with concentrated sulfuric or hydrochloric acid, but reacts rapidly in hot acid solutions. The compound reacts rapidly with ammonium hydroxide but more slowly with sodium hydroxide.1 It is reported that no decomposition occurs below 120° when the solid is heated, but that at higher temperatures the solid is decomposed and phosphorus (III) chloride is liberated 1 however, decomposition at 80° has been observed. Tetrakis[phos-phorus(III) chloride] nickel appears to be nonvolatile. 

Eventually we formed carbonyls in the liquid phase by redox disproportionation of nickel and cobalt derivatives of organic thioacids. In the reaction between nickel(II) dithiobenzoate and carbon monoxide in the presence of HS ion we assumed the formation of a sulfur-bridged nickel(IV) complex (VII, 32). More recent investigations (84), however, have shown that half the nickel appears as a monomeric nickel(II) complex of the same empirical formulation, formed by insertion of a sulfur atom in the dithio ligand, the other half of the nickel being reduced to nickel(O) by the sulfide. 

A correlation between the differences in the amount of Ni and Fe present in a majority of these ashes and their leachability was not observed. This lack of correlation suggests that these elements are in a matrix that is not readily solubilized by the water used to generate the leachate. Hansen and Fisher (4) have shown the iron to be primarily in the insoluble silicate matrix and nickel appears to be associated with an acid insoluble phase. However, for all of the other elements, the differences in amounts leached from the fly ashes were correlated with the bulk differences found in the fly ashes. 

It has not been possible so far to establish that Cr is an essential element required by plants, however, addition of Cr to soils deficient in the element has been shown to increase growth rates and yields of potatoes, maize, rye, wheat or oats (Scharrer and Schropp, 1935 Huffman and Allaway, 1973 Bertrand and De Wolf, 1986). Nickel appears to be an essential element for plants (Farago and Cole, 1988). Zerner and coworkers (Dixon et al., 1975) demonstrated that urease isolated from jack bean (Canavalia ensiformis) was a nickel enzyme. Eskew et al. (1983) have shown that Ni is an essential micronutrient for legumes. Most plants contain nickel in the range 1 - 6 mg kg-1 (Vanselow, 1966 Hutchinson, 1981). The uptake of Ni is enhanced by low pH values, and available nickel increases at pH less than 6.5 as a consequence of the breakdown of Ni complexes in the soil with Fe and Mn oxides. Uptake of nickel by plants and questions of toxicity and tolerance have been reviewed by Farago and Cole (1988). Nickel toxicity toward plants has been reviewed by Vanselow (1966) and Hutchinson (1981). 

Nickel Monocyanide.—Reduction of potassium nickelo-cyanide, K2Ni(CN)4, with potassium amalgam yields a red salt, K2Ni(CN)3, in which nickel appears to be monovalent. Upon acidifying, an orange-yellow precipitate of the monocyanide is obtained, NiCN. It readily oxidises to nickel cyanide, Ni(CN)a.4... 

Manganese appeared randomly at the 0-5-/xg/cm2 level in a pattern similar to, but lower than, that of iron, indicating that it probably was present in the processing water. Nickel appeared generally at the l-/xg/cm2 level in the Holland-made papers and at the 3-/xg/cm2 level in the pink Amies papers. It is likely that mercury, whose concentrations are questionable and not plotted here, actually is responsible for the pink color. 

Other binary nickel compounds, probably all containing Ni" but not all stoichiometric, may be obtained by the direct reaction of nickel with various nonmetals such as P, As, Sb, S, Se, Te, C, and B. Nickel appears to form a nitride Ni3N. The oxide K2Ni02 contains linear [O—Ni11—O]2" units.1... 

Metals Lead, calcium, arsenic, methyl mercury, organotins (TBTO, i.e., bis(tris- -butyltin)oxide), nickel Appears to depend of speciation of metal [35]... 

Workers at The Solution Makers noticed that recent shipments of solid iron (III) chloride and solid nickel (II) chloride purchased from ICCNA to make 1000 ppm solutions of iron and nickel appeared to be a slightly different color compared to the same chemicals purchased earlier. When they prepared the solutions, they too appeared to be a slightly different color compared to solutions prepared earlier. They are suspicious that these chemicals are out-of spec (meaning they do not meet the specifications required by law) due to a contaminant. Before they start pointing fingers and say that ICCNA s chemicals are out-of-spec, however, they would like to have an independent analysis done by our laboratory. The contract does not call for us to identify a contaminant. Our purpose is to simply discover whether or not there is, in fact, a colored contaminant present. The Solution Makers have given us samples of both the clean iron (III) chloride and nickel (II) chloride and also the chemicals suspected of being contaminated. 

The promoting action of cobalt and nickel appear to be similar and Ni promotes... 

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