Mercury cobalt carbonyl

The especially stable mercury-cobalt carbonyl, which is readily soluble in organic solvents, forms quantitatively according to the equation... 

The mercury compounds HgFe(CO)4 and Fe(CO)4(HgX)2 (X = C1, Br, I), which were the first representatives of non-ionic metal derivatives of iron carbonyl hydrides, were discovered by Hock and Stuhlmann (V, 36). During investigations into the preparation of cobalt carbonyls from cobalt halides under CO pressure, in the presence of another metal as a halogen acceptor, we discovered the mixed metal carbonyls M[Co(CO)4]2 (M = Zn, Cd, Hg, Sn) and M[Co(CO)4]3 (M = In, Tl) (44), e.g.,... 

The cobalt carbonylates of Cd and In gave mixtures of dimers at the same concentrations at which Zn[Co(CO)4]2 also gave dimer mixtures. However, both catalysts also responded to Lewis acid cocatalysis. The mercury compound in itself was also unselective, but gave Binor-S in the presence of BPa O(C2H6)2. The catalyst In[Co(CO)4]3 did not produce a norbornadiene trimer. Concerted trimerization, though not completely unlikely, would require all three norbornadiene molecules in... 

A variety of cobalt carbonyl derivatives have been obtained in which the cobalt atom is o-bonded to an element other than carbon. These have been obtained both by wet methods involving metathesis of a solution of [Co(CO)4] with an appropriate derivative of the element to be bonded to cobalt and by dry methods involving high-pressure reactions of carbon monoxide with a mixture of cobalt metal or one of its compounds and an appropriate derivative of the other element. Thus, treatment of aqueous solutions of [Co(CO)4] with silver nitrate or mercury(II) cyanide gave the derivatives AgCo(CO)4 or Hg[Co(CO)4], respectively (220). The mercury derivative can also be prepared by the dry method, involving treatment of a mixture of mercury(II) bromide and cobalt metal with 200 atm of carbon monoxide at 150° C (247). The silver derivative AgCo(CO)4 could not be prepared by the dry method (247). The yellow zinc and cadmium derivatives M[Co(CO)4]2 (M = Zn or Cd) can be obtained by treatment of cobalt(II) bromide, cobalt metal, or dicobalt octacarbonyl with zinc or cadmium metal in the presence of carbon monoxide under pressure (247). 

Photoreactions can also be used to both synthesize and fragment mixed-metal oligomers and clusters. An example of such a transformation is the photochemical extrusion of mercury from the heterotrimetallic cobalt-mercury cluster complex HgCo2(CO)8. Photolysis into the MMCT transition of HgCo2(CO)g results in the formation of cobalt carbonyl, Co2(CO)g, and elemental mercury ... 

A new type of catalyst, a cobalt carbonyl complex, has been found for low-temperature (viz. 50 °C) homogeneous hydroformylation of alkenes. Nafion-H (a superacidic perfluorinated resin sulphonic acid) impregnated with mercury is recommended as a catalyst for the hydration of alkynes R C=CR (R = H or aryl, R = H, alkyl, or aryl) to form ketones R CH2C0R. Two mild methods for the hydrolysis of vinyl halides to ketones have been described one utilizes Bp3,Et20 and mercury(ii) acetate in acetic acid and the second mercury(ii) acetate in trifluoroacetic acid/ ... 

Vanhoye and coworkers [402] synthesized aldehydes by using the electrogenerated radical anion of iron pentacarbonyl to reduce iodoethane and benzyl bromide in the presence of carbon monoxide. Esters can be prepared catalytically from alkyl halides and alcohols in the presence of iron pentacarbonyl [403]. Yoshida and coworkers reduced mixtures of organic halides and iron pentacarbonyl and then introduced an electrophile to obtain carbonyl compounds [404] and converted alkyl halides into aldehydes by using iron pentacarbonyl as a catalyst [405,406]. Finally, a review by Torii [407] provides references to additional papers that deal with catalytic processes involving complexes of nickel, cobalt, iron, palladium, rhodium, platinum, chromium, molybdenum, tungsten, manganese, rhenium, tin, lead, zinc, mercury, and titanium. 

In the cobalt complex, each cobalt atom has a trigonal bipyramidal coordination geometry, whereas, in the manganese complex, each manganese atom is octahedrally coordinated. In both cases, the equatorial carbonyl groups are bent towards the central mercury atom. The structures of the related compounds... 

Although the mechanism of the reaction is not completely clear, it is certain that, organomercurials behave as alkylating agents of the cobalt complex. In improving this reaction, Seyferth found that carbonylation of mercurials can be carried out in the presence of catalytic amounts of Co2(CO)8 or Hg[Co(CO)4]2 under UV irradiation. 

So-called ultrafine metal powders below 1 i in diameter can be made by pyrogenic dissociation of the vapors of the carbonyls of iron, nickel, and cobalt. Aluminum of a particle size below the resolving power of the electron microscope has been formed by evaporation and condensation under vacuum in an inert atmosph e. Similarly, evaporated magnesium has been quenched by JP-4 fuel for directly making a slurry fuel. Also, long ball-milling fine magnesium powder in the presence of a surfactant can lead to particles below I n. Iron or nickel electrolytically deposited on a mercury cathode form very active, often pyrophoric, fine powdm that, however, can be stabilized in order to be handled in air. 

Ruj(CO)i,(n-HgCl)( Xj-ampy)] (Hampy=2-atnino-6-methylpyridine) with a variety of metal carbonyls affords complexes in which the ruthenium triangle is linked via a mercury atom to either cobalt, molybdenum or tungsten , while addition of diphenylmercury to [CpMFe2(CO),(n-H)(n,-COMe)] (M=Co,Rh) affords [ CpMFe2(CO)7(p3-COMe), (, -Hg)], the mercury atom bridging two iron-iron vectors . ... 

Carbonate formation from an alcohol and carbon monoxide is known to take place in the presence of a number of metal and non-metal redox couples, e.g. palladium, platinum, cobalt, copper, nickel, rhodium, mercury, selenium, and bromine. Most of these are also active in the oxidation of CO to CO2 in water, due to the similarity of the reaction pathways for CO2 and carbonate formation, which involve intermediate hydroxy carbonyl and alkoxy carbonyl species, respectively. Competition between carbon dioxide and carbonate formation is a major factor that has to be considered when catalyst re-oxidation is carried out by oxygen, as in most technical developments, since in this case water is co-produced in the reaction system. 

Metals can also be introduced by adsorption of the elemental vapor or melt, for instance in the case of mercury or alkali metals. Adsorption of molecular "precursors such as carbonyls of iron, cobalt, nickel and molybdenum, and subsequent thermal or photochemical decomposition has become an important approach for metals that are difficult to reduce. Other ligands such as alkyls or acetylacetonates have also been used for this purpose. In all these cases, thermal decomposition carries the risk of excessive mobility of the precursors or intermediates such that agglomeration and particle formation at the external surface of the zeolite crystals can occur. Barrer has described the synthesis of salt-bearing zeolites including the famous dry synthesis of ultramarin in 1828, which is sodalite containing intercalated Na-polysulphides. Adsorption of numerous non-ionic and salt species into zeolites was also described, either as such or as precursors for oxides, hydroxides, or metals. 

Mercury, di(cobalt tetra-carbonyl)- s. Di(cobalt tetracarbonyl)mercury Mercury(II) fluoride as reactant 16, 682 Mercury(II) oxide 16, 137, 193, 495, 620 Mercurypyrimidines... 

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