Nickel reaction

With this in view, we studied the development of the dehydrofluorination reaction of CF3CH2CI as function of the degree of fluorination of chromium oxide. Moreover, nickel and chromium oxide catalysts were prepared and tested for the dehydrofluorination reaction. Nickel oxide, a basic compound [S], could poison selectively the tes involved during the dehydrofluorination reaction. 

A-methoxy-carbonyl-2-pyrroline 235 Michael reactions, nickel catalysis 97-8 monophospholanes with pendant f-BuS group 17,19... 

According to the free energy change associated with the pertinent reaction, nickel will form nickel tetracarbonyl at low temperatures, and this carbonyl will become unstable and revert back to nickel and carbon monoxide at moderate temperatures. The Mond process for refining nickel is based on these features. In this process, impure nickel is exposed to carbon monoxide gas at 50 °C, whereby volatile nickel tetracarbonyl (Ni(CO)4) forms. No impurity present in the crude nickel reacts with carbon monoxide. Since formation of the... 

Nickel-catalyzed carbonylation of a-ketoalkynes has also been reported by Arzoumanian et al. under phase-transfer conditions.94 The carbonylation gave either furanone or unsaturated carboxylic acids depending on the substituents of substrates (Eq. 4.53). A similar reaction, nickel-catalyzed cyanation of a-ketoalkynes with KCN in water, was also reported to afford unsaturated hydroxylactams (Eq. 4.54).95... 

Ikeda and coworkers351 performed [2 + 2 + 2] cycloadditions of diynes with a,ji-enones using NiCl2/Zn (1 10) as the catalytic couple. In these reactions, nickel dichloride... 

The cell reactions are shown in Fig. 8.21, from which it can be seen that overdischarge and overcharge reactions are possible. Use is made of the overdischarge reaction to allow the assembly of the cell without the addition of elemental sodium. To the products of the discharge reaction - nickel and sodium chloride - is added a small quantity of aluminium which on the first charge generates enough excess sodium to prime the sodium electrode ... 

To meeet the demands of high-temperature applications such as hydrocarbon steam reforming and partial oxidation reactions, nickel-based alloys are frequently taken into consideration [10]. 

The heat thus generated in-situ over the packed bed is then available for the endothermic steam reforming reactions. Nickel was chosen as the metal for UMR, since it is the most common catalyst for the steam reforming reactions and can be readily oxidized and reduced. 

The toss of stereospecificity in the reaction nickel-catalyzed is supposed to be a result of a one-elec Iron transfer from nickel (0) to the epoxide (Scheme 13). 

The catalytic hydrogenation of benzene has been carried out as a model reaction to increase the hydrogenated cyclic compounds from aromatics. Catalyst samples containing nickel on different supports were prepared and tested. It was found that a-Al203 supported nickel showed the best activity for benzene conversion reaction. Nickel metal area, its dispersion and nickel crystal size were determined. The best activity is obtained with 40% nickel concentration (as oxide) and at the optimum nickel crystallite size of 196A° and optimum metal area of 10.8m2/g. 

No satisfactory containing material has been found in which to carry out this reaction. Nickel is at present the best known containing material, but it... 

It is well known that olefins dimerize on contact with a nickel oxide catalyst at elevated temperature. Since the discovery of their specific activity in catalysing dimerization reactions, nickel-based catalysts have been the subject of intensive mechanistic and kinetic studies directed toward identifying and understanding the active sites responsible for this property. Earlier nickel catalysts were homogeneous however, nickel deposited on different supports has shown high selectivity towards alkene dimerization (see Table 5, page 276). 

Other metals of Groups 8 to 10 have very different characteristics in respect of reactions of the butenes with hydrogen and deuterium as might be expected from the way they behave in the ethene- (and propene-) deuterium reactions, nickel, palladium, ruthenium, rhodium and osmium are able under some conditions to exhibit much higher values of r,/rfc, so that the butenes are able to achieve their equilibrium concentrations before their hydrogenation is finished. 

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