With nickel

In 2013, Sengmany eta/. [184] reported the Ni-catdyzed synthesis of 3-amino-6-aryl- and 3-amino-6-heteroarylpyridazines - compounds that exhibit diverse biologic2il activities - using an electrochemical method. A large functional group diversity was shown on both the 3-amino-6-chloropyridazine and the aryl or heteroaryl halide reagent. The yields were satisfactory. 

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An iron saucepan with a layer of sand at the bottom is quite satisfactory the distilling flask is immersed in the bath to within 2 cm. of the side arm, and two asbestos boards, cut to fit the neck of the flask, rest on top of the bath (as in Fig. II, 5, 3).. Somewhat better rosiilts are obtained if the bath is filled with nickel shot. 

Gobalt occurs in the minerals cobaltite, smaltite, and erythrite, and is often associated with nickel, silver, lead, copper, and iron ores, from which it is most frequently obtained as a by-product. It is also present in meteorites. 

The resulting macrocyclic ligand was then metallated with nickel(II) acetate. Hydride abstraction by the strongly electrophilic trityl cation and proton elimination resulted in the formation of carbon-carbon double bonds (T.J. Truex, 1972). 

The reaction is initiated with nickel carbonyl. The feeds are adjusted to give the bulk of the carbonyl from carbon monoxide. The reaction takes place continuously in an agitated reactor with a Hquid recirculation loop. The reaction is mn at about atmospheric pressure and at about 40°C with an acetylene carbon monoxide mole ratio of 1.1 1 in the presence of 20% excess alcohol. The reactor effluent is washed with nickel chloride brine to remove excess alcohol and nickel salts and the brine—alcohol mixture is stripped to recover alcohol for recycle. The stripped brine is again used as extractant, but with a bleed stream returned to the nickel carbonyl conversion unit. The neutralized cmde monomer is purified by a series of continuous, low pressure distillations. 

Meta.1 Complexes. The importance of Ni complexes is based on their effectiveness as quenchers for singlet oxygen. Of disadvantage is their low colorfastness and their lower ir-reflectance compared to cyanine dyes (qv) therefore they are used in combination with suitable dyes. Numerous complexes are described in the Hterature, primarily tetrathiolate complexes of Pt or Ni, eg, dithiolatonickel complexes (3). Well known is the practical use of a combination of ben2othia2ole dyes with nickel thiol complexes in WORM disks (Ricoh, TDK) (17). 

Fresh reducing gas is generated by reforming natural gas with steam. The natural gas is heated in a recuperator, desulfurized to less than 1 ppm sulfur, mixed with superheated steam, further preheated to 620°C in another recuperator, then reformed in alloy tubes filled with nickel-based catalyst at a temperature of 830°C. The reformed gas is quenched to remove water vapor, mixed with clean recycled top gas from the shaft furnace, reheated to 925°C in an indirect fired heater, and injected into the shaft furnace. For high (above 92%) metallization a CO2 removal unit is added in the top gas recycle line in order to upgrade the quaUty of the recycled top gas and reducing gas. 

Ma.nufa.cture. Nickel carbonyl can be prepared by the direct combination of carbon monoxide and metallic nickel (77). The presence of sulfur, the surface area, and the surface activity of the nickel affect the formation of nickel carbonyl (78). The thermodynamics of formation and reaction are documented (79). Two commercial processes are used for large-scale production (80). An atmospheric method, whereby carbon monoxide is passed over nickel sulfide and freshly reduced nickel metal, is used in the United Kingdom to produce pure nickel carbonyl (81). The second method, used in Canada, involves high pressure CO in the formation of iron and nickel carbonyls the two are separated by distillation (81). Very high pressure CO is required for the formation of cobalt carbonyl and a method has been described where the mixed carbonyls are scmbbed with ammonia or an amine and the cobalt is extracted as the ammine carbonyl (82). A discontinued commercial process in the United States involved the reaction of carbon monoxide with nickel sulfate solution. 

Substituted derivatives of nickelocene, where one ring has been replaced, include the complex cyclopentadienyl nitrosyl nickel [12071 -73-7], (7T-C3H3)NiNO, a red Hquid, mp -41°C. A review of nitrosyl complexes with nickel is available (89). The dimer complex... 

Eye and Skin Contact. Some nickel salts and aqueous solutions of these salts, eg, the sulfate and chloride, may cause a primary irritant reaction of the eye and skin. The most common effect of dermal exposure to nickel is allergic contact dermatitis. Nickel dermatitis may occur in sensitized individuals following close and prolonged contact with nickel-containing solutions or metallic objects such as jewelry, particularly pierced earrings. It is estimated that 8—15% of the female human population and 0.2—2% of the male human population is nickel-sensitized (125). 

Other Higher Oleiins. Linear a-olefins, such as 1-hexene and 1-octene, are produced by catalytic oligomerization of ethylene with triethyl aluminum (6) or with nickel-based catalysts (7—9) (see Olefins, higher). Olefins with branched alkyl groups are usually produced by catalytic dehydration of corresponding alcohols. For example, 3-methyl-1-butene is produced from isoamyl alcohol using base-treated alumina (15). 

Another use of 4-/ f2 octylphenol is ia the productioa of uv stabilizers. 4-/ f2 -Octylpheaol reacts with sulfur dichloride to yield the thio-hisphenol derivative, which thea reacts with nickel acetate to form 2,2 -thiobis(4-/ f2 octylphenolate)-A/-butylamiQe nickel [14516-71 -3]. This type of stabilizer is widely used in the production of outdoor carpeting based on polypropylene fibers. Nickel compounds give a green discoloration which limits their apphcatioas. A second class of uv stabilizers based on the benzotriazole stmcture. 2-(2 -hydroxy-5 -/ f2 octylphenyl)benzotriazole [3147-75-9] is produced from 4-/ i -octylphenol (55). 

Tin ores and concentrates can be brought into solution by fusing at red heat in a nickel cmcible with sodium carbonate and sodium peroxide, leaching in water, acidifying with hydrochloric acid, and digesting with nickel sheet. The solution is cooled in carbon dioxide, and titrated with a standard potassium iodate—iodide solution using starch as an indicator. 

The determination of tin in metals containing over 75 wt % tin (eg, ingot tin) requites a special procedure (17). A 5-g sample is dissolved in hydrochloric acid, reduced with nickel, and cooled in CO2. A calculated weight of pure potassium iodate (dried at 100°C) and an excess of potassium iodide (1 3) are dissolved in water and added to the reduced solution to oxidize 96—98 wt % of the stannous chloride present. The reaction is completed by titration with 0.1 Af KIO —KI solution to a blue color using starch as the indicator. 

Diacetone-L-sorbose (DAS) is oxidized at elevated temperatures in dilute sodium hydroxide in the presence of a catalyst (nickel chloride for bleach or palladium on carbon for air) or by electrolytic methods. After completion of the reaction, the mixture is worked up by acidification to 2,3 4,6-bis-0-isoptopyhdene-2-oxo-L-gulonic acid (2,3 4,6-diacetone-2-keto-L-gulonic acid) (DAG), which is isolated through filtration, washing, and drying. With sodium hypochlorite/nickel chloride, the reported DAG yields ate >90% (65). The oxidation with air has been reported, and a practical process was developed with palladium—carbon or platinum—carbon as catalyst (66,67). The electrolytic oxidation with nickel salts as the catalyst has also... 

Eor the negative electrolyte, cadmium nitrate solution (density 1.8 g/mL) is used in the procedure described above. Because a small (3 —4 g/L) amount of free nitric acid is desirable in the impregnation solution, the addition of a corrosion inhibitor prevents excessive contamination of the solution with nickel from the sintered mass (see Corrosion and corrosion inhibitorsCorrosion and corrosion control). In most appHcations for sintered nickel electrodes the optimum positive electrode performance is achieved when one-third to one-half of the pore volume is filled with active material. The negative electrode optimum has one-half of its pore volume filled with active material. 

The methods of choice for beryUium oxide in beryUium metal are inert gas fusion and fast neutron activation. In the inert gas fusion technique, the sample is fused with nickel metal in a graphite cmcible under a stream of helium or argon. BeryUium oxide is reduced, and the evolved carbon monoxide is measured by infrared absorption spectrometry. BeryUium nitride decomposes under the same fusion conditions and may be determined by measurement of the evolved nitrogen. Oxygen may also be determined by activation with 14 MeV neutrons (20). The only significant interferents in the neutron activation technique are fluorine and boron, which are seldom encountered in beryUium metal samples. 

In Moroccan deposits, cobalt occurs with nickel in the forms of smaltite, skuttemdite, and safflorite. In Canadian deposits, cobalt occurs with silver and bismuth. Smaltite, cobaltite, erythrite, safflorite, linnaeite, and skuttemdite have been identified as occurring in these deposits. AustraUan deposits are associated with nickel, copper, manganese, silver, bismuth, chromium, and tungsten. In these reserves, cobalt occurs as sulfides, arsenides, and oxides. 

Most copper deposits are (/) porphyry deposits and vein replacement deposits, (2) strata-bound deposits in sedimentary rocks, (J) massive sulfide deposits in volcanic rocks, (4) magmatic segregates associated with nickel in mafic intmsives, or (5) native copper, typified by the lava-associated deposits of the Keweenaw Peninsula, Michigan. 

The property most frequently cited in connection with the use of Ti dental or medical appHances is titanium s unique biocompatibiHty. This helps practitioners avoid occasional allergic reactions that occur with nickel or chromium alloys, and removes concerns about the toxic or carcinogenic potential of appHances that contain nickel, chromium, or beryUium. Wrought alloys of titanium are used for orthodontic wires because of their unique elastic... 

Composites. Another type of electro deposit in commercial use is the composite form, in which insoluble materials are codeposited along with the electro-deposited metal or alloy to produce particular desirable properties. Polytetrafluoroethylene (PTFE) particles are codeposited with nickel to improve lubricity (see Lubrication and lubricants). SiHcon carbide and other hard particles including diamond are co-deposited with nickel to improve wear properties or to make cutting and grinding tools (see Carbides Tool materials). 

Esters can be obtained from halogenated olefins using a metal carbonyl catalyst (87), eg, /n j -l-bromo-2-phenylethylene is treated with nickel carbonyl in the presence of methanol to afford the corresponding methyl cinnamate (see Cinnamic acid). 

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