Cobalt(II) acetate


Cobalt acetate is the cobalt salt of acetic acid. It is commonly found as the tetrahydrate Co2·4 H2O, abbreviated Co2·4 H2O. It is used as a catalyst.

Synthesis and structure

Like many other transition metal acetates, cobalt acetate forms by the reaction of cobalt oxide or hydroxide and acetic acid:
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. The analogous nickel acetate is isostructural.
Various hydrates are known including Co2·H2O and 5·0.5 H2O. These are coordination polymers:

Reactions and uses

Cobalt acetate is a precursor to various oil drying agents, catalysts that allow paints and varnishes to harden.
Anhydrous cobalt acetate is a widely used source of cobalt in the synthesis of materials, catalyst, and complexes.
Oxidation of acetic acid solutions of cobalt acetate, e.g. with ozone, gives cobalt acetates, which are strong oxidants.

Safety

Cobalt salts are poisonous.