Production of Nickel Carbonyl

The reaction is very rapid, so that the partial pressure of CO at the metal surface is essentially zero. The carbonyl forms as a gas that diffuses as fast as it forms from the metal surface to the bulk gas stream. 

We wish to estimate the rate of mass transfer of CO(1) during the production of nickel carbonyl [Ni(CO)4](2) under the following conditions  

SOLUTION For every mole of carbonyl that diffuses to the bulk gas stream, 4 mol of CO diffuse to the metal surface. Thus, the flux ratios are determined as follows  

When the flux ratios are fixed, we may evaluate the mass transfer rate factor 0 from Eq. 8.2.20 

It is convenient to identify the mole fraction Xjq as the composition at the catalyst surface. The mole fraction in the bulk gas is and is 0.5. The mole fraction is zero, since carbon monoxide is entirely consumed by the reaction at the catalyst surface. Thus, 

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Figure 8.5. Composition profiles in the vapor film surrounding nickel spheres in the production of nickel carbonyl. Arrows indicate actual directions of mass transfer.

Example 1.16 Production of Nickel Carbonyl Steady-State, One-Dimensional Binary Flux Calculation... 

Nickel sulfate also is made by the reaction of black nickel oxide and hot dilute sulfuric acid, or of dilute sulfuric acid and nickel carbonate. The reaction of nickel oxide and sulfuric acid has been studied and a reaction induction temperature of 49°C deterrnined (39). High purity nickel sulfate is made from the reaction of nickel carbonyl, sulfur dioxide, and oxygen in the gas phase at 100°C (40). Another method for the continuous manufacture of nickel sulfate is the gas-phase reaction of nickel carbonyl and nitric acid, recovering the soHd product in sulfuric acid, and continuously removing the soHd nickel sulfate from the acid mixture (41). In this last method, nickel carbonyl and sulfuric acid are fed into a closed-loop reactor. Nickel sulfate and carbon monoxide are produced the CO is thus recycled to form nickel carbonyl. 

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. 

When acid catalysts are employed, in the absence of nickel carbonyl, the mechanism involves initial attack by a proton, followed by attack of the resulting carbocation on carbon monoxide to give an acyl cation, which, with water, gives the product ... 

The dissolution of porous minerals, the combustion of porous carbon, the reaction between porous carbon and carbon dioxide, and the formation of nickel carbonyl from pure nickel are some examples of fluid-solid reactions where the reactant solid is porous and where no solid reaction product is formed. A reaction of this type can be represented as... 

A solution of 10.5 g. (0.046 mol) of freshly distilled bis(tri-fluoromethyl)-l,2-dithiete (Note 2) in 200 ml. of n-pentane is cooled to —10° in a 1-1. round-bottomed flask equipped with an efficient reflux condenser and protected from moist air by a dry nitrogen blanket. A solution of 3.0 ml. (0.023 mol) of nickel carbonyl dissolved in 100 ml. of w-pentane is added down the condenser in one portion to this solution. The mixture is swirled to mix. An intense blue-violet color develops in about 15 to 20 seconds and after 1 to 2 minutes, vigorous evolution of carbon monoxide occurs. This evolution subsides in 10 minutes and the deep violet solution is allowed to warm to 0° during 2 hours to ensure complete reaction. Most of the pentane is removed by distillation at atmospheric pressure, the remaining 50 to 60 ml. is removed in vacuo (0.1 mm.), and the resultant crystalline mass is evacuated (0.1 mm.) at 50° for 4 hours. The crude product consists of shiny black-purple needles and weighs 11.8 g. (98%). Recrystallization from dry benzene (Note 3) gives shiny black crystals, m.p. 134 to 135° (sealed tube). The complex is air-stable but should be kept out of contact with moist air. 

A3-Pyrroline formation with carbonyl insertion also occurs during the reaction of /V-sulfinylarylamines with diphenylcyclopropenone in the presence of nickel carbonyl (Scheme 36).64 Phenyl isocyanate does not give a pyrroline product under these reaction conditions, hence the SO-CO exchange probably occurs within an intermediate metallocycle. The reaction... 

Ni(CO)4 is the sole binary carbonyl complex of the elements of group 10 that is stable (Table 8.1). However, very few studies in which Ni(CO)4 is used in the preparation of catalysts have been reported [43]. This is probably due to the difficulty of manipulation of Ni(CO)4 and its very high toxicity. However, surface Ni(CO)4 species have been identified after the interaction of CO with highly dispersed supported nickel catalysts prepared by other routes [44]. Recent interest in the use of Ni(CO)4 has focused on the controlled production of nickel nanoparticles for specific purposes, such as in automotive converters [45]. The use of nickel tetracarbonyl as an agent for the nucleation process in the growth of single-wall carbon nanotubes has also been reported [46]. 

Adipic acid can also be made from THF, obtained from furfural. It is carbonylated in the presence of nickel carbonyl-nickel iodide catalyst. Furfural is a chemurgic product obtained by the steam-acid digestion of corn cobs, oat hulls, bagasse, or rice hulls. 

Attempts to purify the material further met with little success because of its extreme sensitivity toward oxygen. Recrystallization from ether, for instance, in a modified Schlenk tube (25), with exclusion of air, invariably led to an off-colored product. An attempt to sublime the product in a high vacuum resulted in complete decomposition. Analysis even on the crude product, however, confirmed its identity as a disubstituted derivative of nickel carbonyl. 

Other substitution products of nickel tetracarbonyl have also been reported examples49 are o-phenylene-bisdimethylarsine-dicarbonyl nickel and dipyridyl-dicarbonyl nickel. The infrared spectra indicate that bonds formed by the carbonyl groups are similar to those in nickel tet-ra, Carbonyl. 

The usual activation of carbon monoxide by coordination appears to involve complexes in which the caibon atom bonded to the metal is rendered slightly positive, and thus more readily attacked by electron rich species such as ethylemc or acetylenic linkages. An example is seen in the reaction of nickel carbonyl and aqueous acetylene, which results in the production of acrylic add. 

Reductive alkylation of ammonia may proceed under mild conditions over nickel catalysts. In examples using Raney Ni, temperatures ranging from 40 to 150°C and hydrogen pressures of 2-15 MPa have been used to obtain satisfactory results.3,4 In general, the reductive alkylation of ammonia with carbonyl compounds may produce primary, secondary, and tertiary amines, as well as an alcohol, a simple hydrogenation product of the carbonyl compound (Scheme 6.1). The selectivity to respective amine depends primarily on the molar ratio of the carbonyl compound to ammonia, although the nature of catalyst and structure of the carbonyl compound are also important factors for the selectivity. As an example, the reaction of benzaldehyde in the presence of 1 equiv of ammonia in ethanol over Raney Ni gave benzylamine in an 89.4% yield while with 0.5 molar equivalent of ammonia dibenzylamine was obtained in an 80.8% yield (eq. 6.1).4... 

In ammonia production, storage, and handling the main potential health hazard is the toxicity of the product itself. For this reason this section concentrates on ammonia only. Other toxic substances such as carbon monoxide or traces of nickel carbonyl (which may be formed during shut down in the methanation stage) may be only a risk in maintenance operations and need appropriate protection provisions as well as blanketing or flushing with nitrogen. 

Synthesis of maerolides. The intramolecular coupling reaction of allylic halides (I, 722-723 2, 290-292 3, 211) has now been shown to be applicable to the synthesis of maCrocyclic lactones. Thus addition of the dibromo ester (1) to 6 eq. of nickel carbonyl in N-methylpyrrolidone effects cyclization to the macrolide (2) as the major product. 

Routes to dialkyl (732) and diperfluoroarylnickel(II) compounds (5< 7) stabilized by bipyridyl have been reported. The addition of phenanthroline to solutions of nickel carbonyl induces disproportionation to Ni(II) and Ni(—1), e.g., [Ni(phen)3][Ni2(CO)a] is a typical product (373). 

Nickel Carbonyl. Reaction of nickel carbonyl with dinitrogen tetroxide in the liquid state follows that outlined for cobalt carbonyl. No nitrite is observed in the product, which is pure Ni(N03)2.2N204 heating gives the anhydrous nitrate. It has been customary to attribute the production of nitrate in this way to the heterolytic dissociation of the tetroxide which is possible in the liquid state. This is certainly true of solvolytic processes—e.g.,... 

Reaction with diazoalkanes. Catalytic amounts of nickel carbonyl decompose diazoalkanes to products evidently formed from an intermediate carbene. Use of a large excess of reagent in the presence of ethanol leads to formation of carboxylic acid esters in yields of 20-25%. 

Use of nickel carbonyl to add 1 mol of HCN to 1,3-butadiene may be the first example of hydrocyanation by a homogeneous nickel catalyst. That work also recorded the important observation that substantial improvement in nitrile product yield results from conducting the reaction in the presence of ( 115)3 or (C H5)3As. This work led to extensive studies to develop effective nickel hydrocyanation catdysts. Virtually all subsequent developments have focused on finding the most effective nickel complex and the identification and application of promoters to improve catalyst efficiency and life. ... 

Ever since Parkyns (60) prepared nickel particles on oxide (A1203, Si02) surfaces by decomposition of nickel carbonyl, metal cluster compounds (alkoxides, carbonyls, organometallics, etc.) have been used increasingly for the production of laboratory metal catalysts (Table I), and several reviews have appeared on this subject (6l-65a,b). 

Nickel, cobalt, and iron catalysts are cmnmonly used for the Fischer-Tropsch s thesis. Nickel catalysts have been prepared by precipitation from a nitrate solution with potassium carbonate in the presence of thoria and kieselguhr in the proportions lOONiilSThOzilOO kieselguhr. It is not desirable to employ nickel catalysts at low temperatures and elevated pressures because the formation of nickel carbonyl is excessive. In the temperature range of 170-220°C at. low pressures, both liquid and gaseous products are obtained. As the temperature is increased to 300-350°C and the pressure increased to 300-400 psi, nickel catalysts produce only methane. Thus, these catal nsts can be used for making a gas from coal comparable in heating value to natural gas. 

Secondary and tertiary a-carbonyl allq l bromides or a-cyano allq l bromides also react with terminal alkenes in the presence of nickel catalysts, forming the corresponding a-alkenylated products of the carbonyl compounds or nitriles (Scheme 14.20). This transformation shows different regioselectivity from those mentioned above. ... 

The heterocyclic biphosphine (CF3 P-CF2)2 (for preparation see p. 250) displaces 2 moles of carbon monoxide from an excess of nickel carbonyl to give an unstable product thought to be (CF3-P-CF2)a Ni(CO)3 2. ... 

Several attempts have been made to measure the heat of combustion of nickel carbonyl. The most satisfactory is that of Fischer et al. 46). They used benzoic acid as a combustion aid, tested the homh gases after combustion for traces of unbumed Ni(CO)4 CO, and analyzed the solid product... 

Ethylene reacts with carbon monoxide and water in the presence of nickel carbonyl to give propionic acid in high yield. If care is taken to maintain a high concentration of propionic acid in the reaction mixture and the temperature, which is normally 300 in the propionic acid synthesis, is decreased to 240 °C propionic acid anhydride is formed in high yield in the presence of Ni(CO)4. Propionic acid ethyl ester is the main product in the reaction of ethylene, carbon monoxide and water (low water concentration must be applied) with cobalt carbonyls instead of Ni(CO)4. The conversion of ethylene with carbon monoxide in dilute alkaline medium with the aid of potassium nickel cyanide gives propionyl propionic acid [403-405]. At higher temperatures and without pH correction in the same reaction mainly polyketones with the sequences -(CHg-CHg-CO)- are formed. If the reaction is carried out in absence of water or alcohols and in presence of palladium iodide as catalyst, a mixture of hexenolide isomers is the main product. Colorless polyketones of the same structure are obtained if an excess of ethylene is treated with carbon monoxide in the presence of complex palladium salts as catalysts in an alcoholic hydrogen halide solution at 100 °C and 700 atm [406]. 

Bases coordinating through nitrogen atoms normally stimulate disproportionation of nickel carbonyl to carbonyl-free cations and polynuclear carbonylnickelates (3). In the cases of pyridine, morpholine, a-picoline, and piperidine, this reaction has been demonstrated to proceed via a neutral complex [Ni(CO)3L] (331). When the base is o-phenanthroline (331,332) or dipyridyl (333) the primary product, e.g., [Ni(CO)2(o-phen)J (331, 332), does not disproportionate and may be isolated. Very careful work has shown that the reaction of Ni(CO)4 and liquid ammonia gives as intermediates nonionic compounds [Ni(CO)3NH3] and [Ni(CO)2(NH3)2], both of which disproportionate above —60°C (334). 

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