513-79-1 cobalt carbonate

In the nickel—carbon and cobalt—carbon systems, the nickel carbide (3 1) [12012-02-1], Ni C, and cobalt carbide (3 1) [12011-59-5] C03C, are isomorphous with Fe C and exist only at low temperatures. The manganese—carbon system contains manganese carbide (3 1) [12121 -90-3] Mn C, isomorphous with Fe C, and manganese carbide (23 6) [12266-65-8] isomorphous with chromium carbide (23 6) [12105-81 -6] These... 

The mauve colored cobalt(II) carbonate [7542-09-8] of commerce is a basic material of indeterminate stoichiometry, (CoCO ) ( (0 )2) H20, that contains 45—47% cobalt. It is prepared by adding a hot solution of cobalt salts to a hot sodium carbonate or sodium bicarbonate solution. Precipitation from cold solutions gives a light blue unstable product. Dissolution of cobalt metal in ammonium carbonate solution followed by thermal decomposition of the solution gives a relatively dense carbonate. Basic cobalt carbonate is virtually insoluble in water, but dissolves in acids and ammonia solutions. It is used in the preparation of pigments and as a starting material in the preparation of cobalt compounds. 

Cobalt(II) acetylacetonate [14024-48-7] cobalt(II) ethyUiexanoate [136-52-7] cobalt(II) oleate [14666-94-5] cobalt(II) linoleate [14666-96-7] cobalt(II) formate [6424-20-0], and cobalt(II) resinate can be produced by metathesis reaction of cobalt salt solutions and the sodium salt of the organic acid, by oxidation of cobalt metal in the presence of the acid, and by neutralization of the acid using cobalt carbonate or cobalt hydroxide. 

Chrornium—cobalt—alurninum oxide [68187-11-1]—Cl Pigment Blue 36, Cl No. 77343. A blue—green pigment obtained by calcining a mixture of chromium oxide, cobalt carbonate, and aluminum oxide. It may contain small amounts (<1% each) of oxides of barium, boron, siUcon, and nickel. 

B12 and related organocobalt chemistry formation and cleavage of cobalt-carbon bonds. P. J. Toscano and L. G. Marzillo, Prog. Inorg. Chem., 1984, 31,105-204 (677). 

Fig. 1.—A simple cubic framework of trisilver cobalticyanide. The circles, in increasing size, represent silver, cobalt, carbon, and nitrogen, respectively.

Investigations of the cobalt-carbon bond energies in organometallic cobalt porphyrins continue to attract interest, originally because of their similarity to coenzyme B 2, and more recently because of their role in the catalysis of free radical... 

Niu, S., Hall, M. B., 1997, Comparison of Hartree-Fock, Density Functional, Mpller-Plesset Perturbation, Coupled Cluster, and Configuration Interaction Methods for the Migratory Insertion of Nitric Oxide into a Cobalt-Carbon Bond , J. Phys. Chem. A, 101, 1360. 

General descriptive/synthetic chemistry Cobalt carbon-bonded compounds10-12 coordination compounds2-9,13-15... 

As examples. Table 8 records some observations on d—d and charge transfer absorption bands in metal/protein systems. The examination of the spectrum of cobalt carbonic anhydrase (d—d) and of iron conalbumin (charge-transfer) permitted a prediction of the ligands from the protein to the metal. The predictions have now been substantiated by other methods. 

Lenhert and Hodgkin (15) revealed with X-ray diffraction techniques that 5 -deoxyadenosylcobalamin (Bi2-coenzyme) contained a cobalt-carbon o-bond (Fig. 3). The discovery of this stable Co—C-tr-bond interested coordination chemists, and the search for methods of synthesizing coen-zyme-Bi2 together with analogous alkyl-cobalt corrinoids from Vitamin B12 was started. In short order the partial chemical synthesis of 5 -de-oxyadenosylcobalamin was worked out in Smith s laboratory (22), and the chemical synthesis of methylcobalamin provided a second B 12-coenzyme which was found to be active in methyl-transfer enzymes (23). A general reaction for the synthesis of alkylcorrinoids is shown in Fig. 4. 

Fig. 28. Routes of cobalt-carbon bond cleavage showing possible electronic arrangements of the resulting spin labeled derivative...

The results of this work leads one to the conclusion that the catalytic intermediate is, a cobalt(II) species. The cobalt-carbon bond cleaves homolytically to give an organic free radical. If the initial cleavage gave a carbanion and cobalt(III), the ESR signal would not disappear, and if... 

In view of the ready commercial availability and apparent stability of the hexahy-drate, it is probable that the earlier report of explosion on impact, and deflagration on rapid heating [1] referred to the material produced by partial dehydration at 100°C, rather than the hexahydrate [2], The caked crystalline hydrated salt, prepared from aqueous perchloric acid and excess cobalt carbonate with subsequent heated evaporation, exploded violently when placed in a mortar and tapped gently to break up the crystalline mass, when a nearby dish of the salt also exploded [3]. Subsequent investigation revealed the probable cause as heating the solid stable hexahydrate to a temperature ( 150°C) at which partial loss of water produced a lower and endothermic hydrate (possibly a trihydrate) capable of explosive decomposition. This hazard may also exist for other hydrated metal perchlorates, and general caution is urged [4,5],... 

Rautala, P., and J. T. Norton Tungsten-Cobalt-Carbon System. J. Metals... 

Chemistry Formation and Cleavage of Cobalt Carbon Bonds. 31 105... 

Cobalt carbide (3 1), 4 649t, 691 Cobalt carbonate, analysis, 7 237t CobaltCII) carbonate, 7 230 uses, 7 239t... 

Given the reaction and the very high stability constants involved, the production of cobalt carbonic anhydrase would require a solution not of ACS-grade cobalt nitrate but a 99.999999999999. .. 999% pure cobalt nitrate solution. What happened in the lab synthesis was that trace metals in the ACS-grade salt were selectively bound to the apo-carbonic anhydrase because their stability constant advantage was orders of magnitude over that of cobalt. The sample used to discover this was sub-milligram in mass. 

The substitution behavior of coenzyme B12, in which a cobalt-carbon bond is present between the Co(III) center and the 5 -desoxy-... 

Such a peculiarity has also been observed in many other compounds with metal-carbon bonds, especially cobalt-carbon. As part of a study (using the above-mentioned extended CNDO method) of the AM(CO)3 isoelectronic series (AM from 772-C2H4Ni to rj6-C6H6Cr) it was shown that, in the t 3-C3HsCo derivative, the allyl group was linked to cobalt by means of the two C(H2) carbons and not predominantly by the C(H) carbon atom, despite the fact that Co—C(H2) = 2.10 A as compared with Co—C(H) = 1.98 A (55). 

Complexation of the nitrile to the cobalt atom (end-on or side-on) can occur followed by insertion into the cobalt-carbon bond to give a seven-membered intermediate (Fig. 4b). 

The strength of the cobalt-carbon bond is very much influenced by the nature of the other five ligands. If these ligands are varied, cobalt complexes may be obtained having different reactivities of the Co-C bond (45). 

Cobalt-carbon bonds may be formed or cleaved by reactions in which the organic group may be present as ... 

---