Nickel carbonyl, and

AH the common monobasic (107) and dibasic esters (108) of tetrahydrofurfuryl alcohol have been prepared by conventional techniques the dibasic esters and some of the mono esters are effective as primary or secondary plasticizers for vinyl polymers. Tetrahydrofurfuryl acrylate [2399-48-6] and methacrjiate [2455-24-5] specialty monomers, have been produced by carbonylation (nickel carbonyl and acetylene) of the alcohol (109) as weU as by direct esterification (110—112) and ester interchange (111). 

Nickel carbonyl is volatile, has Htde odor, and is extremely toxic. Symptoms of dangerous exposure may not appear for several days. Effective medical treatment should be started immediately. The plant should be designed to ensure containment of nickel carbonyl and to prevent operator contact. 

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. 

Tetramethylcyclobutadiene dichloride [76404-16-5] can be prepared by reaction of nickel carbonyl and 3,4-dichlorotetramethylcyclobutene (CBD) in polar solvents (103). The complex is black-violet, mp 185°C (dec). 

Nickel catalysts were used in most of the methanation catalytic studies they have a rather wide range of operating temperatures, approximately 260°-538°C. Operation of the catalytic reactors at 482°-538°C will ultimately result in carbon deposition and rapid deactivation of the catalysts (10). Reactions below 260°C will usually result in formation of nickel carbonyl and also in rapid deactivation of the catalysts. The best operating range for most fixed-bed nickel catalysts is 288°-482 °C. Several schemes have been proposed to limit the maximum temperature in adiabatic catalytic reactors to 482°C, and IGT has developed a cold-gas recycle process that utilizes a series of fixed-bed adiabatic catalytic reactors to maintain this temperature control. 

Nickel carbonyl and tetrachloropropadiene react in a wide variety of solvents to give the crystalline title compound which is extremely shock-sensitive, and explodes if touched when dry. 

Overall, nickel is not an immediate threat to the health of plants, animals, and humans at environmentally encountered levels, except in the case of nickel carbonyl, and progress has been made toward minimizing or eliminating occupational nickel exposure. 

The ability of nickel complexes, e.g., nickel carbonyl and its phosphine derivatives, to catalyze polymerization and other reactions of olefins and acetylenes has been studied extensively (46, 53), particularly by Reppe. 

Trimethylbenzaldehyde has been prepared from mes-itylglyoxylic acid,3,4 from mesitylene, nickel carbonyl, and aluminum chloride, and in excellent yield from mesitylene, hydrogen cyanide, and hydrogen chloride, as well as from mesitylene, carbon dioxide, and hydrogen chloride, in the presence of aluminum and cuprous chlorides.6 The above method is that applied to the preparation of other aldehydes by Rosen-mund and Zetzsche.7... 

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. 

A transient orange complex is formed in this reaction, which is very probably chloro-/i3-allylnickel(l 1) dimer, a complex that can be obtained from nickel carbonyl and allyl chloride in an inert solvent (8). The probable mechanism of the carbonylation then becomes clear with the additional facts that bromo-fi3-allylnickel(Il) dimer reacts with carbon monoxide to give unstable bromodicarbonyl(3-butenoyl)nickel(II), which then reacts further with CO to form nickel carbonyl and 3-butenoyl bromide (6). Six separate steps are believed to be involved ... 

Palladium catalyzes the carbonylation of allylic, vinylic, benzylic, and aromatic halides in alcohols to form esters under conditions similar to those required by the nickel carbonyl catalyst (11). The palladium-catalyzed reaction offers the advantage of not requiring the use of highly toxic and volatile nickel carbonyl, and perhaps higher catalyst activity, although accurate comparisons have not been made. Like the nickel reaction, the palladium reaction... 

Polymerization was carried out in benzene in the presence of bis-(7r-allylnickel halides). The latter were prepared from nickel carbonyl and allyl halide (allyl bromide, crotyl chloride, bromide, or iodide etc.). The results of the polymerization runs are reported in Table I. The data indicate that all of the bis(7r-allylnickel halides) initiate by themselves the stereospecific butadiene polymerization yielding a polymer with 97-98% 1,4-units. The cis-l,4/trans-l,4 ratio depends on the halide in the dimeric r-allylnickel halide but not on the nature of allylic ligand. The case of bis(7r-crotylnickel halides) shows the effect of halide on microstructure, for whereas (C4H7NiCl)2 initiates cis- 1,4-polybutadiene formation, trans-1,4 polymers are produced by (C4H7NiI)2. The reactivity increase in the series Cl < Br < I. 

Significance of the constitutional nature of nickel carbonyls and their w-complex derivatives in poisonings and cancerogenesis New reagent—nickel tetracarbonyl... 

Write an electronic structural fomjula for nickel carbonyl, and discuss the arrangement of the electrons around the nickel atoms in relation to the structure of krypton. Iron forms a carbonyl Fe(CO)5, chromium a car bonyl Cr(CO)g discuss the electronic structures of these substances. 

The physical properties have the expected trend, while the thermal instability of the palladium derivative appears anomalous and can perhaps be attributed to a combination of kinetic and thermodynamic factors. (Platinum should be thermodynamically more unstable but kinetically stable.) In any case, it appears that Ni(PF3)4 is more stable than nickel carbonyl, and this confirms that the palladium and platinum tetratri-fluorophosphine derivatives could be prepared. 

Until about 1957, only metals toward the end of the transition series, such as Pd, Pt, Cu, Ag, and Hg, were known to form mono-olefin complexes. In 1959 Schrauzer 219, 220) prepared the first olefin complex of nickel, starting with nickel carbonyl and acrylonitrile ... 

This scheme implies addition reactions followed by substitution reactions, but the intermediate stages have not been identified. The NO2 substitution reactions are no doubt similar in principle to, but rather more complicated than, the reaction between nickel carbonyl and nitrogen dioxide (see below). The structure of the product, and the bonding of the NO2 groups to the metal, are discussed in connection with the nickel compound, which has been more fully investigated. 

Reaction with CO at —60° C. yielded nickel carbonyl and a Ci3 ketone. Addition of one mole of P(C2H5)3 formed a crystalline complex which was identical with the compound obtained from cyclododecatriene-centro-nickel and... 

Vinyl bromides are directly aminocarbonylated by nickel carbonyl and amines. Very similarly, Rh (CO)i6 and BU4NCI as cat yst convert allylphosphates to. -y-unsaturated amides via rr-allylrhodium complexes (equation 43). Although palladium(O) complexes are more reactive than rhodium(I) complexes, palladium(O) complexes undergo side reactions, like reductive elimination in the presence of carbon monoxide, and direct nucleophilic attack by amines. 

The Occupational Safety and Health Administration permissible exposure limit (PEL) time-weighted average (TWA) for nickel metal and other nickel compounds as nickel is 1 mg m the PEL TWA for nickel carbonyl is 0.007 mg m . The ACGIH threshold limit values (TLVs) for nickel metal, insoluble compounds, soluble compounds, nickel carbonyl, and nickel subsulflde, all expressed as nickel, are 1.5, 0.2, 0.1, 0.12, and 0.1 mgm, respectively. Except for nickel carbonyl, all of the TLVs are expressed as inhalable particulate. The US EPA reference dose for soluble nickel salts is 0.02 mg kg day, but this value is undergoing reevaluation, due to the availability of several relevant new studies. 

Hydrocarboxylation pf acetylenes. In 1953 Reppe" published details of his cur-bonylation" reaction, effected with use of nickel carbonyl and described more appropriately us a hydrocarboxylation (addition of the elements of formic acid). 

Aminocarbonylation can be achieved by use of a mixture of nickel carbonyl and an amine, as shown in a typical example. 

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