Cobalt(II) acetate

Chemical compound From Wikipedia, the free encyclopedia

Cobalt(II) acetate is the cobalt salt of acetic acid. It is commonly found as the tetrahydrate Co(CH3CO2)2·4 H2O, abbreviated Co(OAc)2·4 H2O. It is used as a catalyst.

Quick facts Names, Identifiers ...
Cobalt(II) acetate
Names
IUPAC name
Cobalt(II) acetate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.000.687 Edit this at Wikidata
UNII
  • InChI=1S/2C2H4O2.Co/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 checkY
    Key: QAHREYKOYSIQPH-UHFFFAOYSA-L checkY
  • InChI=1/2C2H4O2.Co/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2
    Key: QAHREYKOYSIQPH-NUQVWONBAX
  • ionic form: [Co+2].[O-]C(=O)C.[O-]C(=O)C
  • coordination form (anhydrate): O=C(C)O[Co]OC(C)=O
  • coordination form (tetrahydrate): O=C(C)O[Co-4]([O+H2])([O+H2])([O+H2])([O+H2])OC(C)=O
Properties
Co(C2H3O2)2
Molar mass 177.021 g/mol (anhydrous)
249.081 g/mol (tetrahydrate)
Appearance Pink crystals (anhydrous)
intense red crystals (tetrahydrate)
Odor vinegar (tetrahydrate)
Density 1.705 g/cm3 (tetrahydrate)
Melting point 140 °C (284 °F; 413 K) (tetrahydrate)
Soluble
Solubility soluble in alcohol, dilute acids, pentyl acetate (tetrahydrate)
+11,000·10−6 cm3/mol
1.542 (tetrahydrate)
Hazards
GHS labelling:[1]
GHS08: Health hazardGHS09: Environmental hazard
Danger
H317, H334, H341, H350i, H360F, H410
P203, P233, P260, P271, P272, P273, P280, P284, P302+P352, P304+P340, P318, P321, P333+P317, P342+P316, P362+P364, P391, P403, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Lethal dose or concentration (LD, LC):
503 mg/kg (oral, rat)
Safety data sheet (SDS) J.T. Baker MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X markN verify (what is checkYX markN ?)
Close

Synthesis and structure

Like many other transition metal acetates, cobalt(II) acetate forms by the reaction of cobalt oxide or hydroxide and acetic acid:

CoO + 2 CH3CO2H + 3 H2O → Co(CH3CO2)2·4H2O

The tetrahydrate has been shown by X-ray crystallography to adopt an octahedral structure, the central cobalt centre being coordinated by four water molecules and two acetate ligands.[2] The analogous nickel acetate is isostructural.[3]

Various hydrates are known including Co(CH3CO2)2·H2O and [Co(CH3CO2)2]5·0.5 H2O. These are coordination polymers:[4]

Segment of the Co(OAc)2(H2O) chain

Reactions and uses

Cobalt acetate is a precursor to various oil drying agents, catalysts that allow paints and varnishes to harden.[5]

Anhydrous cobalt acetate is a widely used source of cobalt in the synthesis of materials,[6] catalyst,[7] and complexes.[8]

Oxidation of acetic acid solutions of cobalt(II) acetate, e.g. with ozone, gives cobalt(III) acetates, which are strong oxidants.[9]

References

Related Articles

Wikiwand AI