Cobalt carbonyl derivatives

A number of cobalt carbonyl derivatives have been subjected to y-irradiation and subsequent EPR spectroscopic investigation. 

Subtle differences in the behavior of azoarenes toward cobalt carbonyl derivatives are observed in regard to metal-complex formation. Azobenzene is transformed by dicobalt octacarbonyl in processes of orthometallation and carbonyl insertion into 2-phenylindazolin-3-one (see Section IV,D,2). In contrast, cyclopentadienylcobalt dicarbonyl effects N—N bond cleavage, and carbonylation of the isolable complex 88a provides 1 -phenylbenzimid-azolin-2-one (Scheme 106).171... 

Withers, H.P., Eliezer, K.F., and Mitchell, J.W. 1990. Slurry-phase Fischer-Tropsch synthesis and kinetic studies over supported cobalt carbonyl derived catalysts. Ind. Eng. Chem. Res. 29 1807-14. 

THE DECOMPOSITION OF COBALT OCTACARBONYL AND SUBSTITUTED BINUCLEAR COBALT CARBONYL DERIVATIVES IN THE PRESENCE OF TRIPHENYL PHOSPHINE... 

Benzyl- and phenylacetyl derivatives of tetracarbonylcobalt(I) are believed to be important intermediates in the cobalt-catalyzed carbonylation of benzyl halides to phenylacetic acidi2twi and to phenylpyruvic acid ", carried out under phase transfer catalysis in the presence of catalytic amounts of a cobalt-carbonyl derivative. The carbonylation to phenylacetic acid proceeds as follows ... 

Ryang and Tsutsumi at Osaka University obtained an acyloin from alkyllithium and Ni(CO)4 (Eq. (5.56)) [64]. Later, Corey and Hegedus applied this ob.servation to an acyl group tran.sfer reaction using nickel carbonyl (Eq. (5.57)) [65] and a cobalt carbonyl derivative [66]. 

Both Co2(CO)g and Co4(CO),2 are oxidized by air even in the solid state, and by halogens. With the latter, complete decomposition to CO and Co(II) halides occurs. Reaction of cobalt carbonyl derivatives with I2 in pyridine is frequently used for analyses by gas volumetry of CO evolved. Octacarbonyldicobalt, Co2(CO)g, is attacked by organic substances that contain active protons and converted to the corresponding Co(II) salts , as in reactions for Fe(CO)j [equations (1) and (m), 14.6.2.3.2]. Included here is reaction of Co2(CO)g with cyclopentadiene to give dicarbonylcyclopentadienylcobalt(I) as a dark red oil (b.p. 75 C/22 torr) ... 

Also rare earth metal-cobalt bonds are proposed for products from reactions of rare earth trichlorides and cobalt carbonyl derivatives (Suleimanov et al., 1982e). 

Beletskaya IP, Magomedov GK, Voskoboinikov AZ (1990) Heterometallic catalysts. Cobalt carbonyl derivatives of lanthanides in catalysis of octene-1 hydroformylation. J Organomet Chem 385 289-295... 

Octahedral cluster iridiiam carbonyl derivatives have also been described (275), but these have been investigated in less detail than their cobalt or rhodium analogs. They are obtained by the alkali-metal reduction of Irit(C0)i2 in a manner somewhat similar to the preparation of octahedral cluster cobalt carbonyl derivatives by the alkali-metal reduction of Coit(C0)i2 Reaction of Irij(C0)i2 with sodium metal in tetrahydrofuTcin first gives the tetrahedral cluster anion Hirij (CX7) i" aind then the dark brown, octahedral cluster anion Ir0(CO)i5 , which can be isolated as its tetraethylammonixam salt (275). ... 

Elemental sulfur and some organic sulfur compounds inhibit hydroformylation and hydrogenation catalyzed by cobalt carbonyls (1 2). In order to elucidate the mechanism of this "poisoning" effect, several new, sulfur-containing cobalt carbonyl derivatives have been prepared. 

The (cobalt carbonyl)-(carbon disulfide) complexes prepared in this laboratory by KLUMPP and coworkers (5, 6) belong apparently to a different class of sulfur-containing cobalt carbonyl derivatives. 

B1 SULFUR-CONTAINING COBALT CARBONYL DERIVATIVES,... 

The insertion of carbon monoxide into a C—M bond is a common reaction for alkyl derivatives of the late transition elements. It has been reported for Mo, Mn, Fe, Co, Ni, Pd, and Pt compounds. The insertion of CO into the C —Co bond of cobalt carbonyl derivatives is a key step in the 0x0 reaction and catalytic carboxylation processes (see Section IV,D). The CO insertion reaction is frequently reversible but sometimes only the reverse reaction, CO elimination, is known, e.g.,... 

Some kinetic studies involving the reactions of various cobalt carbonyl derivatives with triphenylphosphine have recently been reported. The rate constants were measured for the reactions of a variety of acylcobalt tetra-carbonyl derivatives with triphenylphosphine according to the following equation 237)... 

In a further study the reaction rates of a variety of cobalt carbonyl derivatives of different types with triphenylphosphine were measured (238). The following series of reactivity were observed ... 

An interesting series of cobalt carbonyl derivatives are the deep violet trinuclear derivatives of general formula YCCo3(CO)9. These were first prepared by treatment of the acetylene complexes Co2(CO)6(RC2H) with... 

The compounds YCCo3(CO)9 form purple crystalline derivatives soluble in organic solvents, but insoluble in water. Despite the presence of three cobalt atoms all of the compounds except for [Co3(CO)9C] 2 may be sublimed readily in vacuum, and some of them are reported to distill with steam without decomposition (222). They appear to be some of the most air-stable cobalt carbonyl derivatives. 

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). 

Heating a mixture of dicobalt octacarbonyl and iron pentacarbonyl in acetone for several hours results in the more complex iron-cobalt carbonyl derivative [Co(acetone)9][FeCo3(CO)i2] (32)... 

The use of the cobalt triad carbonyls as catalysts continues to provide many papers for this report. Publications cover the silylformylation of 1-Hexyne catalyzed by diodium-cobalt carbonyl clusters the formation of hydroxycarbene cobalt carbonyl derivatives, the use of rhodium cluster carbonyls in the water-gas shift reaction Rh4(CO) 2> and Co3Rh(CO)] 2 catalysts for the hydrosilation of isoprene, cyclohexanone and cyclohexenone catalytic reduction of NO by CO and the carbonylation of unsaturated compounds The chemistry of iridium carbonyl cluster complexes has been extended by making use of capping reactions with HgCl2and Au(PPh3)Q... 

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