Cobaltous Chloride

Title: Cobaltous Chloride
CAS Registry Number: 7646-79-9
Additional Names: Cobalt dichloride
Molecular Formula: Cl2Co
Molecular Weight: 129.84
Percent Composition: Cl 54.61%, Co 45.39%
Line Formula: CoCl2
Literature References: Prepn of anhydr from Co powder and Cl2: Osthoff, West, J. Am. Chem. Soc. 76, 4732 (1954); from the acetate and acetyl chloride: Watt et al., ibid. 77, 2752 (1955); by dehydration of the hexahydrate with SOCl2: Hecht, Z. Anorg. Chem. 254, 51 (1947). Prepn of the hexahydrate by treating an aqueous soln of a cobaltous salt with HCl: ACS Monograph Series no. 149, entitled "Cobalt - Its Chemistry, Metallurgy, and Uses," R. S. Young, Ed. (Reinhold, New York, 1960) p 76. Review: de Bie, Doyen, Cobalt 15, 3-13; 16, 3-15 (1962). Toxicity studies: G. J. A. Speijers et al., Food Chem. Toxicol. 20, 311 (1982); P. P. Singh, A. Y. Junnarkar, Indian J. Pharmacol. 23, 153 (1991). Review of toxicology: B. Venugopal, T. D. Luckey, Environ. Qual. Safety Suppl. 1, 4-73 (1975).
Properties: Pale-blue hygroscopic leaflets; colorless in very thin layers; turns pink on exposure to moist air. mp 735°; bp 1049°; d425 3.367. Dec 400° on long heating in air. Sublimes at 500° in HCl gas, forming iridescent, fluffy, colorless cryst. Sol in water, alcohols, acetone, ether, glycerol, pyridine. LD50 in mice, rats (mg/kg): 360.0, 171.0 orally; 92.6, 36.9 i.p.; 23.3, 4.3 i.v. (Singh, Junnarkar).
Melting point: mp 735°
Boiling point: bp 1049°
Density: d425 3.367
Toxicity data: LD50 in mice, rats (mg/kg): 360.0, 171.0 orally; 92.6, 36.9 i.p.; 23.3, 4.3 i.v. (Singh, Junnarkar)
Derivative Type: Hexahydrate
CAS Registry Number: 7791-13-1
Properties: Monoclinic crystals. Structure is reported to be [CoCl2(H2O)4].2H2O: Mizuno et al., J. Phys. Soc. Jpn. 14, 383 (1959), C.A. 53, 14630i (1959). Pink to red, slightly deliquesc, monoclinic, prismatic crystals. mp 87°; d20 1.924. On heating loses 4H2O at 52-56° forming the dihydrate, violet or blue crystals, d2525 2.477, stable unless exposed directly to moisture. Loses another H2O by 100°, giving monohydrate, violet, hygroscopic, amorphous solid or needles. Remaining H2O lost at 120-140°. Sol in water, alcohols, acetone, ether, glycerol. pH of 0.2 molar aq soln 4.6. The aq soln is pink to red, but turns blue when heated or when HCl or H2SO4 is added. Keep well closed. LD50 orally in rats: 766 mg/kg (Speijers).
Melting point: mp 87°
Density: d20 1.924; d2525 2.477
Toxicity data: LD50 orally in rats: 766 mg/kg (Speijers)
CAUTION: Large amounts of CoCl2 depress erythrocyte production. May lead to death in children. Other effects include cutaneous flushing, chest pains, dermatitides, tinnitus, nausea and vomiting, nerve deafness, thyroid hyperplasia, myxedema, congestive heart failure. See E. Beutler et al., Clinical Disorders of Iron Metabolism (Grune & Stratton, New York, 1963) pp 175-178.
Use: Invisible ink; humidity and water indicator; in hygrometers; temp indicator in grinding; in electroplating; for painting on glass and porcelain; prepn of catalysts; fertilizer and feed additive; foam stabilizer in beer; as absorbent for military poison gas and ammonia; in manuf of vitamin B12. Radioactive cobalt chloride, 57CoCl2 (half-life 271.79 days, pure gamma emitter) used in Mössbauer effect (nuclear clock).
Therap-Cat: Hematinic.
Therap-Cat-Vet: Nutritional factor. Used in cobalt deficiency in ruminants.
Keywords: Hematinic.
Cobaltous Chromate(III) Cobaltous Cyanide Cobaltous Fluoride Cobaltous Formate Cobaltous Hydroxide