Nomenclature
CAS number: 10210-68-1
Di-μ-carbonylhexacarbonyldicobalt; octacarbonyldicobalt; cobalt tetracarbonyl; cobalt octacarbonyl.
C
8Co
2O
8; mol wt 341.95.
C 28.10%, Co 34.47%, O 37.43%.
Co
2(CO)
8.
Description and references
Prepn: Mond et al., J. Chem. Soc. 97, 798 (1910);
Gilmont, Blanchard, Inorg. Synth. 2, 238 (1946); Wender et al., ibid. 5, 190 (1957); Chini et al., Chim. Ind. (Milan) 55, 120 (1973). Crystal structure: Sumner et al., Acta Crystallogr. 17, 732 (1964). Two isomeric forms exist in soln: Noack, Spectrochim. Acta 19, 1925 (1963);
Bor, ibid. 2065; Noack, Helv. Chim.
Acta 47, 1064, 1555 (1964). Toxicity studies:
Kincaid et al., Arch. Ind. Hyg.
Occup. Med. 10, 210 (1954); Brief et al., Arch. Environ. Health 23, 373 (1971); Kalekin, C.A. 78, 67751z (1973); Spiridonova, Shabalina, Gig. Sanit. 1973, 73, C.A. 78, 119835b (1973). Reviews of prepn,
properties and chemistry of cobalt carbonyls: I. Wender et al., Bull. U.S. Bur. Mines 600, 83 pp (1960); Organic Syntheses via Metal
Carbonyls vol. 1, I. Wender, P. Pino, Eds.
(Interscience, New York, 1968) passim; Chalk, Harrod, “Catalysis
by Cobalt Carbonyls” in Adv. Organomet. Chem. 6, 119-170 (1968); Nicholls in Comprehensive Inorganic Chemistry vol. 3, J.
C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973)
pp 1059-1064.
Properties
Orange platelets obtained by vacuum sublimation.
d 1.87. mp 51°; dec above 52°. Stable in
an atm of H2 and CO; dec on exposure to air. Insol in
water. Sol in organic solvents such as ether, alcohol, CS2, naphtha. Slowly attacked by HCl, H2SO4,
more rapidly by HNO3, Br2. LD50 in mice, rats (mg/kg): 377.7, 753.8 by gavage (Spiridonova, Shabalina).Derivative
Cobalt carbonyl hydride.
Nomenclature
Cobalt hydrocarbonyl; tetracarbonylhydridocobalt; tetracarbonylhydrocobalt. C
4HCoO
4; mol wt 171.98.
C 27.94%, H 0.59%, Co 34.27%, O 37.21%.
Description and references
Unstable catalytic intermediate; active species
in some reactions catalyzed by Co2(CO)8.
Properties
Yellow, toxic, foul-smelling liquid. mp -26°. Dec at room
temp to Co2(CO)8. Sparingly sol in water (3 ×
10-3 moles/l); behaves as a strong acid. Readily oxidized
in air.Caution
Potential symptoms of overexposure
are irritation of eyes, skin, mucous membranes; cough, decreased pulmonary
function, wheezing, dyspnea. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140,
1997) p 74.Use
Catalyst for hydroformylation, hydrogenation, hydrosilation,
isomerization, carboxylation, carbonylation and polymerization reactions.