Reactions reduction with hydrogen

Similar waves in the cathodic polarogram were observed by Donnet and Henrich 58) using oxidized carbon black. The wave disappeared after treatment with isobutyronitrile. It was assumed that isobutyro-nitrile gives an addition reaction with quinones. No reaction with this reagent was observed after reduction with hydrogen iodide, after treatment with aniline, or after treatment with diazomethane. The latter finding confirms the assumption by Studebaker et al. 38) that diazomethane is added to the quinones in the carbon black surface. 

Carbon is able to bind sulfur to its surface. The reaction of sugar charcoal or wood charcoal with elementary sulfur at temperatures of 400-1000° was studied in detail by Wibaut (118-122). In this reaction some carbon disulfide was formed as well as hydrogen sulfide, if hydrogen was present in the samples. The solid reaction products contained considerable amounts of sulfur, up to 20% by weight. The maximum sulfur uptake was observed at 600°. The sulfur was not completely volatized even by heating in a vacuum to 1000° (122). The sulfur came off in elementary form and as carbon disulfide. Neither could the sulfur be removed from the samples by extraction. It was disposed of by powerful chemical attack, e.g., by oxidation or by reduction with hydrogen at 700°. The formation of hydrogen sulfide started at 460°. 

Hexaruthenium carbonyl complexes have been used to prepare Ti02-supported mthenium catalysts for the sulfur dioxide reduction with hydrogen [112, 113], A catalyst derived from [Ru6C(CO)i6] showed higher activity in the production of elemental sulfur at low temperatures than that prepared from RUCI3 as precursor. This catalytic behavior is related with the formation of an amorphous ruthenium sulfide phase that takes place during the reaction over the ex-carbonyl catalyst [112]. 

Reduction with hydrogen sulfide and its salts is sometimes referred to as the Zinin reduction (Org. Reactions 1973, 20,455). 

Mecamylamine Mecamylamine, M2,3,3-tetramethylnorboman-2-ylamine (14.2. 2), is synthesized from 2,3,3-trimethylnorbomen-2, which is reacted in a Ritter reaction conditions with hydrogen cyanide in concentrated snlfuric acid, giving 2,3,3-trimethylnorbor-nan-2-ylformylamine (14.2.1), the reduction of which by lithium aluminum hydride leads to mecamylamine (14.2.2) [32,33]. 

In addition to the activity, other important requirements for the catalyst are the capability to start the reaction rapidly without the necessity for previous reduction with hydrogen and to perform effectively with intermittent operation these are essential properties for the catalyst in reformers, especially for portable and small-scale stationary fuel cell applications. In this respect, Dias and Assaf [61] focused on the potential of Pd, Pt and Ir to promote fast and intermittent ignition of methane ATR in Ni/y-Al203. They concluded that the three metals are very good promoters of the reduction of the nickel catalyst with methane, but the lower cost of palladium makes this metal more suitable than Pt and Ir for small fuel cells. 

The selenides may also be obtained by direct combination of the elements, either by passing selenium vapour over the heated metal in a vacuum or by heating the metal with selenium in a crucible, the reaction being started by means of a magnesium fuse.3 In the case of potassium the reaction is explosive. The compounds may also be obtained by the action of hydrogen selenide on the heated metal,4 on the heated metallic chloride or its vapour, preferably in the presence of nitrogen,5 or by reduction with hydrogen or carbon of an oxysalt such as a selenite.6 Selenides have also been prepared by electrolytic methods.7... 

O-p-tolylsulfonyl-a-D-mannoside (39) in 37% yield. Treatment of (39) with sodium iodide in acetone gave the 6-iodo derivative (40), which underwent reduction with hydrogen in the presence of a nickel boride" catalyst" to give methyl 4-0-benzoyl-2,3-0 carbonyl-6-deoxy-o>-D-manno-side (41) in 95% yield. Reaction of (41) with hydrogen bromide in acetic acid effected replacement of the methoxyl group at C-l, affording crystalline... 

The Kp values for the reactions of hydrogen transfer between primary and secondary alcohols and nitro compounds were calculated using Van Krevelen and Chermin procedure (ref. 4). Similarly as the simple reduction with hydrogen the catalytic hydrogen transfer from alcohols to nitro derivatives is strongly favored thermodynamically. For all studied reactions with primary alcohols the K... 

These substances, like most compounds with peroxide (O—O) bonds, may explode violently and unpredictably. Therefore ozonizations must be carried out with appropriate caution. The general importance of these reactions derives not from the ozonides, which usually are not isolated, but from their subsequent products. The ozonides can be converted by hydrolysis with water and reduction, with hydrogen (palladium catalyst) or with zinc and acid, to carbonyl compounds that can be isolated and identified. For example, 2-butene... 

Reactions (I) and (II) were studied (102) on alloys prepared by thermal decomposition (at 400°C) in air of coprecipitated Ni-Cu carbonates, followed by reduction with hydrogen (at 300 to 400°C). 

The traditional method of isolating the trans-dichlorobis-(ethylenediamine)cobalt(III) chloride salt by evaporation of the reaction mixture to dryness in the steam bath gives some reduction to cobalt(II). To avoid this, the chloride salt in the following procedure is isolated by saturation of the reaction mixture with hydrogen chloride gas and by precipitation with standing at room temperature. As an alternative method, the reaction mixture from the preparation of (carbonato)bis(ethylene-diamine)cobalt(III) chloride can be used as the starting material. 

The kinetic experiments, activity tests, and poisoning experiments were carried out in a gas-flow isothermal fixed bed reactor [6) at the benzene partial pressure of 7.55 kPa hydro gen partial pressure 99.82 kPa thiophene partial pressure 0.032 kPa and the reaction temperatures 403, 427 and 448 K. The size of the commercial cylindrical catalyst pellet was 5x5mm (21% Ni on alumina, supplied by BASF). The nickel oxide containing precursor was activated by reduction with hydrogen at 743 K for 10 hr. 

The dioxide difluorides of U, Np, Pu, and Am have all been isolated. Uranyl fluoride, being an important intermediate in the conversion of enriched UF6 to UO2 for the production of fuel rods for Advanced Gas-Cooled Nuclear Reactors, is undoubtedly the most studied. The majority of papers on UO2F2, therefore, are concerned with its formation from the reaction of UF6 with steam or its conversion to UO2 by reduction with hydrogen. 

Octacarbonyldicobalt decomposes readily at about 50°-60°C to give dodecacarbonyltetracobalt, and this thermal degradation reaction provides a convenient synthesis of Co4(CO)i2 on a small scale (103). Larger quantities of Co4(CO)i2 are better prepared by the reduction with hydrogen of an appropriate C0X2 compound (e.g., X = 2-ethylhexanoate or acetylacetonate) in the presence of Co2(CO)b [Eq. (10)] (104, 105). 

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